Anyone converted 4.0L from R12 to R134a?
07-19-2006, 01:50 AM
#11
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
Hi Sam,
It would be nice if you can vacuum the system before adding R134a, yet, it
is not critical. From my last 2 years' experience, It will still work.
The reason that you have a high pressure reading might be due to the
compressor is not engaging. This is the case for one of my 93 ZJs.
In my case, the compressor side electric cable (factory taped to the
positive cable from the battery) was not plugged fully into the compressor.
Good Luck
Paul
P.S. The cable connector might be partially unplugged when one
replace/disconnect the battery.
<redlinescooby@hotmail.com> wrote in message
news:1153272471.441132.176100@p79g2000cwp.googlegr oups.com...
>I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> had an AC guy try to recover the R12, but he said it was 98% air. I'm
> using one of the InterDynamics kits and thought everything was going
> smoothly. Even though the instructions did not mention it, someone
> told me that I needed to remove the valve core from the low side port,
> since the conversion kit supplied adaptor fitting already has one. I
> have a valve core removal tool, but I can't seem to locate the valve
> core inside the fitting. After installing the adapter fittings, I
> tried to add some R134, but the meter is saying that it's overcharged.
> I don't believe that any R134 is even making it into the system.
> Another guy told me that I need to pull a vacuum on it. Has anyone
> else had this problem before?
>
> Thanks,
>
> Sam
>
It would be nice if you can vacuum the system before adding R134a, yet, it
is not critical. From my last 2 years' experience, It will still work.
The reason that you have a high pressure reading might be due to the
compressor is not engaging. This is the case for one of my 93 ZJs.
In my case, the compressor side electric cable (factory taped to the
positive cable from the battery) was not plugged fully into the compressor.
Good Luck
Paul
P.S. The cable connector might be partially unplugged when one
replace/disconnect the battery.
<redlinescooby@hotmail.com> wrote in message
news:1153272471.441132.176100@p79g2000cwp.googlegr oups.com...
>I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> had an AC guy try to recover the R12, but he said it was 98% air. I'm
> using one of the InterDynamics kits and thought everything was going
> smoothly. Even though the instructions did not mention it, someone
> told me that I needed to remove the valve core from the low side port,
> since the conversion kit supplied adaptor fitting already has one. I
> have a valve core removal tool, but I can't seem to locate the valve
> core inside the fitting. After installing the adapter fittings, I
> tried to add some R134, but the meter is saying that it's overcharged.
> I don't believe that any R134 is even making it into the system.
> Another guy told me that I need to pull a vacuum on it. Has anyone
> else had this problem before?
>
> Thanks,
>
> Sam
>
07-19-2006, 01:50 AM
#12
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
Hi Sam,
It would be nice if you can vacuum the system before adding R134a, yet, it
is not critical. From my last 2 years' experience, It will still work.
The reason that you have a high pressure reading might be due to the
compressor is not engaging. This is the case for one of my 93 ZJs.
In my case, the compressor side electric cable (factory taped to the
positive cable from the battery) was not plugged fully into the compressor.
Good Luck
Paul
P.S. The cable connector might be partially unplugged when one
replace/disconnect the battery.
<redlinescooby@hotmail.com> wrote in message
news:1153272471.441132.176100@p79g2000cwp.googlegr oups.com...
>I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> had an AC guy try to recover the R12, but he said it was 98% air. I'm
> using one of the InterDynamics kits and thought everything was going
> smoothly. Even though the instructions did not mention it, someone
> told me that I needed to remove the valve core from the low side port,
> since the conversion kit supplied adaptor fitting already has one. I
> have a valve core removal tool, but I can't seem to locate the valve
> core inside the fitting. After installing the adapter fittings, I
> tried to add some R134, but the meter is saying that it's overcharged.
> I don't believe that any R134 is even making it into the system.
> Another guy told me that I need to pull a vacuum on it. Has anyone
> else had this problem before?
>
> Thanks,
>
> Sam
>
It would be nice if you can vacuum the system before adding R134a, yet, it
is not critical. From my last 2 years' experience, It will still work.
The reason that you have a high pressure reading might be due to the
compressor is not engaging. This is the case for one of my 93 ZJs.
In my case, the compressor side electric cable (factory taped to the
positive cable from the battery) was not plugged fully into the compressor.
Good Luck
Paul
P.S. The cable connector might be partially unplugged when one
replace/disconnect the battery.
<redlinescooby@hotmail.com> wrote in message
news:1153272471.441132.176100@p79g2000cwp.googlegr oups.com...
>I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> had an AC guy try to recover the R12, but he said it was 98% air. I'm
> using one of the InterDynamics kits and thought everything was going
> smoothly. Even though the instructions did not mention it, someone
> told me that I needed to remove the valve core from the low side port,
> since the conversion kit supplied adaptor fitting already has one. I
> have a valve core removal tool, but I can't seem to locate the valve
> core inside the fitting. After installing the adapter fittings, I
> tried to add some R134, but the meter is saying that it's overcharged.
> I don't believe that any R134 is even making it into the system.
> Another guy told me that I need to pull a vacuum on it. Has anyone
> else had this problem before?
>
> Thanks,
>
> Sam
>
07-19-2006, 01:50 AM
#13
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
Hi Sam,
It would be nice if you can vacuum the system before adding R134a, yet, it
is not critical. From my last 2 years' experience, It will still work.
The reason that you have a high pressure reading might be due to the
compressor is not engaging. This is the case for one of my 93 ZJs.
In my case, the compressor side electric cable (factory taped to the
positive cable from the battery) was not plugged fully into the compressor.
Good Luck
Paul
P.S. The cable connector might be partially unplugged when one
replace/disconnect the battery.
<redlinescooby@hotmail.com> wrote in message
news:1153272471.441132.176100@p79g2000cwp.googlegr oups.com...
>I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> had an AC guy try to recover the R12, but he said it was 98% air. I'm
> using one of the InterDynamics kits and thought everything was going
> smoothly. Even though the instructions did not mention it, someone
> told me that I needed to remove the valve core from the low side port,
> since the conversion kit supplied adaptor fitting already has one. I
> have a valve core removal tool, but I can't seem to locate the valve
> core inside the fitting. After installing the adapter fittings, I
> tried to add some R134, but the meter is saying that it's overcharged.
> I don't believe that any R134 is even making it into the system.
> Another guy told me that I need to pull a vacuum on it. Has anyone
> else had this problem before?
>
> Thanks,
>
> Sam
>
It would be nice if you can vacuum the system before adding R134a, yet, it
is not critical. From my last 2 years' experience, It will still work.
The reason that you have a high pressure reading might be due to the
compressor is not engaging. This is the case for one of my 93 ZJs.
In my case, the compressor side electric cable (factory taped to the
positive cable from the battery) was not plugged fully into the compressor.
Good Luck
Paul
P.S. The cable connector might be partially unplugged when one
replace/disconnect the battery.
<redlinescooby@hotmail.com> wrote in message
news:1153272471.441132.176100@p79g2000cwp.googlegr oups.com...
>I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> had an AC guy try to recover the R12, but he said it was 98% air. I'm
> using one of the InterDynamics kits and thought everything was going
> smoothly. Even though the instructions did not mention it, someone
> told me that I needed to remove the valve core from the low side port,
> since the conversion kit supplied adaptor fitting already has one. I
> have a valve core removal tool, but I can't seem to locate the valve
> core inside the fitting. After installing the adapter fittings, I
> tried to add some R134, but the meter is saying that it's overcharged.
> I don't believe that any R134 is even making it into the system.
> Another guy told me that I need to pull a vacuum on it. Has anyone
> else had this problem before?
>
> Thanks,
>
> Sam
>
07-19-2006, 09:23 AM
#14
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
I did not open any valves. I was expecting a needle valve in the low
side port fitting, but cannot find it. I noticed the fitting also has
a 1/4 inch square type lug coming out at 90 deg angle. Is that the
valve you are talking about. I'm a rookie when it comes to AC systems!
Sam
Jeff DeWitt wrote:
> redlinescooby@hotmail.com wrote:
> > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > using one of the InterDynamics kits and thought everything was going
> > smoothly. Even though the instructions did not mention it, someone
> > told me that I needed to remove the valve core from the low side port,
> > since the conversion kit supplied adaptor fitting already has one. I
> > have a valve core removal tool, but I can't seem to locate the valve
> > core inside the fitting. After installing the adapter fittings, I
> > tried to add some R134, but the meter is saying that it's overcharged.
> > I don't believe that any R134 is even making it into the system.
> > Another guy told me that I need to pull a vacuum on it. Has anyone
> > else had this problem before?
> >
> > Thanks,
> >
> > Sam
> >
>
> It's always a very good idea to throughly pump down a system if you are
> changing the refrigerant.
>
> Is it possible that your gage is measuring the high side instead of the
> low side? And you did open the valves right? I don't mean to be
> insulting but speaking for myself I've had more trouble overlooking the
> stupidest things that were obvious in retrospect.
>
> I don't recommend this but I installed AC on a vehicle that didn't have
> it before, and used a factory evaporator designed for R12 with a modern
> compressor (along with new everything else). This being a new install
> it was of course full of air at normally air pressure. Not having the
> proper equipment to pump it down and then put in just the right amount
> of refrigerant (and just how much R-134a does a non stock AC unit in a
> Studebaker take anyway?!) I started putting refrigerant in until the
> unit was blowing cold and the gage was in the green, worked just fine.
>
> Good luck!
>
> Jeff DeWitt
side port fitting, but cannot find it. I noticed the fitting also has
a 1/4 inch square type lug coming out at 90 deg angle. Is that the
valve you are talking about. I'm a rookie when it comes to AC systems!
Sam
Jeff DeWitt wrote:
> redlinescooby@hotmail.com wrote:
> > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > using one of the InterDynamics kits and thought everything was going
> > smoothly. Even though the instructions did not mention it, someone
> > told me that I needed to remove the valve core from the low side port,
> > since the conversion kit supplied adaptor fitting already has one. I
> > have a valve core removal tool, but I can't seem to locate the valve
> > core inside the fitting. After installing the adapter fittings, I
> > tried to add some R134, but the meter is saying that it's overcharged.
> > I don't believe that any R134 is even making it into the system.
> > Another guy told me that I need to pull a vacuum on it. Has anyone
> > else had this problem before?
> >
> > Thanks,
> >
> > Sam
> >
>
> It's always a very good idea to throughly pump down a system if you are
> changing the refrigerant.
>
> Is it possible that your gage is measuring the high side instead of the
> low side? And you did open the valves right? I don't mean to be
> insulting but speaking for myself I've had more trouble overlooking the
> stupidest things that were obvious in retrospect.
>
> I don't recommend this but I installed AC on a vehicle that didn't have
> it before, and used a factory evaporator designed for R12 with a modern
> compressor (along with new everything else). This being a new install
> it was of course full of air at normally air pressure. Not having the
> proper equipment to pump it down and then put in just the right amount
> of refrigerant (and just how much R-134a does a non stock AC unit in a
> Studebaker take anyway?!) I started putting refrigerant in until the
> unit was blowing cold and the gage was in the green, worked just fine.
>
> Good luck!
>
> Jeff DeWitt
07-19-2006, 09:23 AM
#15
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
I did not open any valves. I was expecting a needle valve in the low
side port fitting, but cannot find it. I noticed the fitting also has
a 1/4 inch square type lug coming out at 90 deg angle. Is that the
valve you are talking about. I'm a rookie when it comes to AC systems!
Sam
Jeff DeWitt wrote:
> redlinescooby@hotmail.com wrote:
> > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > using one of the InterDynamics kits and thought everything was going
> > smoothly. Even though the instructions did not mention it, someone
> > told me that I needed to remove the valve core from the low side port,
> > since the conversion kit supplied adaptor fitting already has one. I
> > have a valve core removal tool, but I can't seem to locate the valve
> > core inside the fitting. After installing the adapter fittings, I
> > tried to add some R134, but the meter is saying that it's overcharged.
> > I don't believe that any R134 is even making it into the system.
> > Another guy told me that I need to pull a vacuum on it. Has anyone
> > else had this problem before?
> >
> > Thanks,
> >
> > Sam
> >
>
> It's always a very good idea to throughly pump down a system if you are
> changing the refrigerant.
>
> Is it possible that your gage is measuring the high side instead of the
> low side? And you did open the valves right? I don't mean to be
> insulting but speaking for myself I've had more trouble overlooking the
> stupidest things that were obvious in retrospect.
>
> I don't recommend this but I installed AC on a vehicle that didn't have
> it before, and used a factory evaporator designed for R12 with a modern
> compressor (along with new everything else). This being a new install
> it was of course full of air at normally air pressure. Not having the
> proper equipment to pump it down and then put in just the right amount
> of refrigerant (and just how much R-134a does a non stock AC unit in a
> Studebaker take anyway?!) I started putting refrigerant in until the
> unit was blowing cold and the gage was in the green, worked just fine.
>
> Good luck!
>
> Jeff DeWitt
side port fitting, but cannot find it. I noticed the fitting also has
a 1/4 inch square type lug coming out at 90 deg angle. Is that the
valve you are talking about. I'm a rookie when it comes to AC systems!
Sam
Jeff DeWitt wrote:
> redlinescooby@hotmail.com wrote:
> > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > using one of the InterDynamics kits and thought everything was going
> > smoothly. Even though the instructions did not mention it, someone
> > told me that I needed to remove the valve core from the low side port,
> > since the conversion kit supplied adaptor fitting already has one. I
> > have a valve core removal tool, but I can't seem to locate the valve
> > core inside the fitting. After installing the adapter fittings, I
> > tried to add some R134, but the meter is saying that it's overcharged.
> > I don't believe that any R134 is even making it into the system.
> > Another guy told me that I need to pull a vacuum on it. Has anyone
> > else had this problem before?
> >
> > Thanks,
> >
> > Sam
> >
>
> It's always a very good idea to throughly pump down a system if you are
> changing the refrigerant.
>
> Is it possible that your gage is measuring the high side instead of the
> low side? And you did open the valves right? I don't mean to be
> insulting but speaking for myself I've had more trouble overlooking the
> stupidest things that were obvious in retrospect.
>
> I don't recommend this but I installed AC on a vehicle that didn't have
> it before, and used a factory evaporator designed for R12 with a modern
> compressor (along with new everything else). This being a new install
> it was of course full of air at normally air pressure. Not having the
> proper equipment to pump it down and then put in just the right amount
> of refrigerant (and just how much R-134a does a non stock AC unit in a
> Studebaker take anyway?!) I started putting refrigerant in until the
> unit was blowing cold and the gage was in the green, worked just fine.
>
> Good luck!
>
> Jeff DeWitt
07-19-2006, 09:23 AM
#16
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
I did not open any valves. I was expecting a needle valve in the low
side port fitting, but cannot find it. I noticed the fitting also has
a 1/4 inch square type lug coming out at 90 deg angle. Is that the
valve you are talking about. I'm a rookie when it comes to AC systems!
Sam
Jeff DeWitt wrote:
> redlinescooby@hotmail.com wrote:
> > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > using one of the InterDynamics kits and thought everything was going
> > smoothly. Even though the instructions did not mention it, someone
> > told me that I needed to remove the valve core from the low side port,
> > since the conversion kit supplied adaptor fitting already has one. I
> > have a valve core removal tool, but I can't seem to locate the valve
> > core inside the fitting. After installing the adapter fittings, I
> > tried to add some R134, but the meter is saying that it's overcharged.
> > I don't believe that any R134 is even making it into the system.
> > Another guy told me that I need to pull a vacuum on it. Has anyone
> > else had this problem before?
> >
> > Thanks,
> >
> > Sam
> >
>
> It's always a very good idea to throughly pump down a system if you are
> changing the refrigerant.
>
> Is it possible that your gage is measuring the high side instead of the
> low side? And you did open the valves right? I don't mean to be
> insulting but speaking for myself I've had more trouble overlooking the
> stupidest things that were obvious in retrospect.
>
> I don't recommend this but I installed AC on a vehicle that didn't have
> it before, and used a factory evaporator designed for R12 with a modern
> compressor (along with new everything else). This being a new install
> it was of course full of air at normally air pressure. Not having the
> proper equipment to pump it down and then put in just the right amount
> of refrigerant (and just how much R-134a does a non stock AC unit in a
> Studebaker take anyway?!) I started putting refrigerant in until the
> unit was blowing cold and the gage was in the green, worked just fine.
>
> Good luck!
>
> Jeff DeWitt
side port fitting, but cannot find it. I noticed the fitting also has
a 1/4 inch square type lug coming out at 90 deg angle. Is that the
valve you are talking about. I'm a rookie when it comes to AC systems!
Sam
Jeff DeWitt wrote:
> redlinescooby@hotmail.com wrote:
> > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > using one of the InterDynamics kits and thought everything was going
> > smoothly. Even though the instructions did not mention it, someone
> > told me that I needed to remove the valve core from the low side port,
> > since the conversion kit supplied adaptor fitting already has one. I
> > have a valve core removal tool, but I can't seem to locate the valve
> > core inside the fitting. After installing the adapter fittings, I
> > tried to add some R134, but the meter is saying that it's overcharged.
> > I don't believe that any R134 is even making it into the system.
> > Another guy told me that I need to pull a vacuum on it. Has anyone
> > else had this problem before?
> >
> > Thanks,
> >
> > Sam
> >
>
> It's always a very good idea to throughly pump down a system if you are
> changing the refrigerant.
>
> Is it possible that your gage is measuring the high side instead of the
> low side? And you did open the valves right? I don't mean to be
> insulting but speaking for myself I've had more trouble overlooking the
> stupidest things that were obvious in retrospect.
>
> I don't recommend this but I installed AC on a vehicle that didn't have
> it before, and used a factory evaporator designed for R12 with a modern
> compressor (along with new everything else). This being a new install
> it was of course full of air at normally air pressure. Not having the
> proper equipment to pump it down and then put in just the right amount
> of refrigerant (and just how much R-134a does a non stock AC unit in a
> Studebaker take anyway?!) I started putting refrigerant in until the
> unit was blowing cold and the gage was in the green, worked just fine.
>
> Good luck!
>
> Jeff DeWitt
07-19-2006, 12:13 PM
#17
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
You need to pump the system down to get all the R12, moisture and air out of
it. You should replace the oil with a R134a compatible oil, either PAG or
ester. O-rings designed to handle R12 cannot really handle R134a and the
higher pressures and temperatures that come with it. These parts are all
cheap, but you have to open the system to the air in order to replace them.
Sure you can do a half-assed job, and the system will work after you charge
it up. But if you do a good job it will still be working years down the
road.
With regard to the valve, it is possible that you have a manual valve in the
low side port, rather than a Schraeder valve. Do you have a digital camera?
Earle
<redlinescooby@hotmail.com> wrote in message
news:1153315422.381330.65000@m73g2000cwd.googlegro ups.com...
> I did not open any valves. I was expecting a needle valve in the low
> side port fitting, but cannot find it. I noticed the fitting also has
> a 1/4 inch square type lug coming out at 90 deg angle. Is that the
> valve you are talking about. I'm a rookie when it comes to AC systems!
>
> Sam
>
>
> Jeff DeWitt wrote:
> > redlinescooby@hotmail.com wrote:
> > > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > > using one of the InterDynamics kits and thought everything was going
> > > smoothly. Even though the instructions did not mention it, someone
> > > told me that I needed to remove the valve core from the low side port,
> > > since the conversion kit supplied adaptor fitting already has one. I
> > > have a valve core removal tool, but I can't seem to locate the valve
> > > core inside the fitting. After installing the adapter fittings, I
> > > tried to add some R134, but the meter is saying that it's overcharged.
> > > I don't believe that any R134 is even making it into the system.
> > > Another guy told me that I need to pull a vacuum on it. Has anyone
> > > else had this problem before?
> > >
> > > Thanks,
> > >
> > > Sam
> > >
> >
> > It's always a very good idea to throughly pump down a system if you are
> > changing the refrigerant.
> >
> > Is it possible that your gage is measuring the high side instead of the
> > low side? And you did open the valves right? I don't mean to be
> > insulting but speaking for myself I've had more trouble overlooking the
> > stupidest things that were obvious in retrospect.
> >
> > I don't recommend this but I installed AC on a vehicle that didn't have
> > it before, and used a factory evaporator designed for R12 with a modern
> > compressor (along with new everything else). This being a new install
> > it was of course full of air at normally air pressure. Not having the
> > proper equipment to pump it down and then put in just the right amount
> > of refrigerant (and just how much R-134a does a non stock AC unit in a
> > Studebaker take anyway?!) I started putting refrigerant in until the
> > unit was blowing cold and the gage was in the green, worked just fine.
> >
> > Good luck!
> >
> > Jeff DeWitt
>
it. You should replace the oil with a R134a compatible oil, either PAG or
ester. O-rings designed to handle R12 cannot really handle R134a and the
higher pressures and temperatures that come with it. These parts are all
cheap, but you have to open the system to the air in order to replace them.
Sure you can do a half-assed job, and the system will work after you charge
it up. But if you do a good job it will still be working years down the
road.
With regard to the valve, it is possible that you have a manual valve in the
low side port, rather than a Schraeder valve. Do you have a digital camera?
Earle
<redlinescooby@hotmail.com> wrote in message
news:1153315422.381330.65000@m73g2000cwd.googlegro ups.com...
> I did not open any valves. I was expecting a needle valve in the low
> side port fitting, but cannot find it. I noticed the fitting also has
> a 1/4 inch square type lug coming out at 90 deg angle. Is that the
> valve you are talking about. I'm a rookie when it comes to AC systems!
>
> Sam
>
>
> Jeff DeWitt wrote:
> > redlinescooby@hotmail.com wrote:
> > > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > > using one of the InterDynamics kits and thought everything was going
> > > smoothly. Even though the instructions did not mention it, someone
> > > told me that I needed to remove the valve core from the low side port,
> > > since the conversion kit supplied adaptor fitting already has one. I
> > > have a valve core removal tool, but I can't seem to locate the valve
> > > core inside the fitting. After installing the adapter fittings, I
> > > tried to add some R134, but the meter is saying that it's overcharged.
> > > I don't believe that any R134 is even making it into the system.
> > > Another guy told me that I need to pull a vacuum on it. Has anyone
> > > else had this problem before?
> > >
> > > Thanks,
> > >
> > > Sam
> > >
> >
> > It's always a very good idea to throughly pump down a system if you are
> > changing the refrigerant.
> >
> > Is it possible that your gage is measuring the high side instead of the
> > low side? And you did open the valves right? I don't mean to be
> > insulting but speaking for myself I've had more trouble overlooking the
> > stupidest things that were obvious in retrospect.
> >
> > I don't recommend this but I installed AC on a vehicle that didn't have
> > it before, and used a factory evaporator designed for R12 with a modern
> > compressor (along with new everything else). This being a new install
> > it was of course full of air at normally air pressure. Not having the
> > proper equipment to pump it down and then put in just the right amount
> > of refrigerant (and just how much R-134a does a non stock AC unit in a
> > Studebaker take anyway?!) I started putting refrigerant in until the
> > unit was blowing cold and the gage was in the green, worked just fine.
> >
> > Good luck!
> >
> > Jeff DeWitt
>
07-19-2006, 12:13 PM
#18
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
You need to pump the system down to get all the R12, moisture and air out of
it. You should replace the oil with a R134a compatible oil, either PAG or
ester. O-rings designed to handle R12 cannot really handle R134a and the
higher pressures and temperatures that come with it. These parts are all
cheap, but you have to open the system to the air in order to replace them.
Sure you can do a half-assed job, and the system will work after you charge
it up. But if you do a good job it will still be working years down the
road.
With regard to the valve, it is possible that you have a manual valve in the
low side port, rather than a Schraeder valve. Do you have a digital camera?
Earle
<redlinescooby@hotmail.com> wrote in message
news:1153315422.381330.65000@m73g2000cwd.googlegro ups.com...
> I did not open any valves. I was expecting a needle valve in the low
> side port fitting, but cannot find it. I noticed the fitting also has
> a 1/4 inch square type lug coming out at 90 deg angle. Is that the
> valve you are talking about. I'm a rookie when it comes to AC systems!
>
> Sam
>
>
> Jeff DeWitt wrote:
> > redlinescooby@hotmail.com wrote:
> > > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > > using one of the InterDynamics kits and thought everything was going
> > > smoothly. Even though the instructions did not mention it, someone
> > > told me that I needed to remove the valve core from the low side port,
> > > since the conversion kit supplied adaptor fitting already has one. I
> > > have a valve core removal tool, but I can't seem to locate the valve
> > > core inside the fitting. After installing the adapter fittings, I
> > > tried to add some R134, but the meter is saying that it's overcharged.
> > > I don't believe that any R134 is even making it into the system.
> > > Another guy told me that I need to pull a vacuum on it. Has anyone
> > > else had this problem before?
> > >
> > > Thanks,
> > >
> > > Sam
> > >
> >
> > It's always a very good idea to throughly pump down a system if you are
> > changing the refrigerant.
> >
> > Is it possible that your gage is measuring the high side instead of the
> > low side? And you did open the valves right? I don't mean to be
> > insulting but speaking for myself I've had more trouble overlooking the
> > stupidest things that were obvious in retrospect.
> >
> > I don't recommend this but I installed AC on a vehicle that didn't have
> > it before, and used a factory evaporator designed for R12 with a modern
> > compressor (along with new everything else). This being a new install
> > it was of course full of air at normally air pressure. Not having the
> > proper equipment to pump it down and then put in just the right amount
> > of refrigerant (and just how much R-134a does a non stock AC unit in a
> > Studebaker take anyway?!) I started putting refrigerant in until the
> > unit was blowing cold and the gage was in the green, worked just fine.
> >
> > Good luck!
> >
> > Jeff DeWitt
>
it. You should replace the oil with a R134a compatible oil, either PAG or
ester. O-rings designed to handle R12 cannot really handle R134a and the
higher pressures and temperatures that come with it. These parts are all
cheap, but you have to open the system to the air in order to replace them.
Sure you can do a half-assed job, and the system will work after you charge
it up. But if you do a good job it will still be working years down the
road.
With regard to the valve, it is possible that you have a manual valve in the
low side port, rather than a Schraeder valve. Do you have a digital camera?
Earle
<redlinescooby@hotmail.com> wrote in message
news:1153315422.381330.65000@m73g2000cwd.googlegro ups.com...
> I did not open any valves. I was expecting a needle valve in the low
> side port fitting, but cannot find it. I noticed the fitting also has
> a 1/4 inch square type lug coming out at 90 deg angle. Is that the
> valve you are talking about. I'm a rookie when it comes to AC systems!
>
> Sam
>
>
> Jeff DeWitt wrote:
> > redlinescooby@hotmail.com wrote:
> > > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > > using one of the InterDynamics kits and thought everything was going
> > > smoothly. Even though the instructions did not mention it, someone
> > > told me that I needed to remove the valve core from the low side port,
> > > since the conversion kit supplied adaptor fitting already has one. I
> > > have a valve core removal tool, but I can't seem to locate the valve
> > > core inside the fitting. After installing the adapter fittings, I
> > > tried to add some R134, but the meter is saying that it's overcharged.
> > > I don't believe that any R134 is even making it into the system.
> > > Another guy told me that I need to pull a vacuum on it. Has anyone
> > > else had this problem before?
> > >
> > > Thanks,
> > >
> > > Sam
> > >
> >
> > It's always a very good idea to throughly pump down a system if you are
> > changing the refrigerant.
> >
> > Is it possible that your gage is measuring the high side instead of the
> > low side? And you did open the valves right? I don't mean to be
> > insulting but speaking for myself I've had more trouble overlooking the
> > stupidest things that were obvious in retrospect.
> >
> > I don't recommend this but I installed AC on a vehicle that didn't have
> > it before, and used a factory evaporator designed for R12 with a modern
> > compressor (along with new everything else). This being a new install
> > it was of course full of air at normally air pressure. Not having the
> > proper equipment to pump it down and then put in just the right amount
> > of refrigerant (and just how much R-134a does a non stock AC unit in a
> > Studebaker take anyway?!) I started putting refrigerant in until the
> > unit was blowing cold and the gage was in the green, worked just fine.
> >
> > Good luck!
> >
> > Jeff DeWitt
>
07-19-2006, 12:13 PM
#19
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
You need to pump the system down to get all the R12, moisture and air out of
it. You should replace the oil with a R134a compatible oil, either PAG or
ester. O-rings designed to handle R12 cannot really handle R134a and the
higher pressures and temperatures that come with it. These parts are all
cheap, but you have to open the system to the air in order to replace them.
Sure you can do a half-assed job, and the system will work after you charge
it up. But if you do a good job it will still be working years down the
road.
With regard to the valve, it is possible that you have a manual valve in the
low side port, rather than a Schraeder valve. Do you have a digital camera?
Earle
<redlinescooby@hotmail.com> wrote in message
news:1153315422.381330.65000@m73g2000cwd.googlegro ups.com...
> I did not open any valves. I was expecting a needle valve in the low
> side port fitting, but cannot find it. I noticed the fitting also has
> a 1/4 inch square type lug coming out at 90 deg angle. Is that the
> valve you are talking about. I'm a rookie when it comes to AC systems!
>
> Sam
>
>
> Jeff DeWitt wrote:
> > redlinescooby@hotmail.com wrote:
> > > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > > using one of the InterDynamics kits and thought everything was going
> > > smoothly. Even though the instructions did not mention it, someone
> > > told me that I needed to remove the valve core from the low side port,
> > > since the conversion kit supplied adaptor fitting already has one. I
> > > have a valve core removal tool, but I can't seem to locate the valve
> > > core inside the fitting. After installing the adapter fittings, I
> > > tried to add some R134, but the meter is saying that it's overcharged.
> > > I don't believe that any R134 is even making it into the system.
> > > Another guy told me that I need to pull a vacuum on it. Has anyone
> > > else had this problem before?
> > >
> > > Thanks,
> > >
> > > Sam
> > >
> >
> > It's always a very good idea to throughly pump down a system if you are
> > changing the refrigerant.
> >
> > Is it possible that your gage is measuring the high side instead of the
> > low side? And you did open the valves right? I don't mean to be
> > insulting but speaking for myself I've had more trouble overlooking the
> > stupidest things that were obvious in retrospect.
> >
> > I don't recommend this but I installed AC on a vehicle that didn't have
> > it before, and used a factory evaporator designed for R12 with a modern
> > compressor (along with new everything else). This being a new install
> > it was of course full of air at normally air pressure. Not having the
> > proper equipment to pump it down and then put in just the right amount
> > of refrigerant (and just how much R-134a does a non stock AC unit in a
> > Studebaker take anyway?!) I started putting refrigerant in until the
> > unit was blowing cold and the gage was in the green, worked just fine.
> >
> > Good luck!
> >
> > Jeff DeWitt
>
it. You should replace the oil with a R134a compatible oil, either PAG or
ester. O-rings designed to handle R12 cannot really handle R134a and the
higher pressures and temperatures that come with it. These parts are all
cheap, but you have to open the system to the air in order to replace them.
Sure you can do a half-assed job, and the system will work after you charge
it up. But if you do a good job it will still be working years down the
road.
With regard to the valve, it is possible that you have a manual valve in the
low side port, rather than a Schraeder valve. Do you have a digital camera?
Earle
<redlinescooby@hotmail.com> wrote in message
news:1153315422.381330.65000@m73g2000cwd.googlegro ups.com...
> I did not open any valves. I was expecting a needle valve in the low
> side port fitting, but cannot find it. I noticed the fitting also has
> a 1/4 inch square type lug coming out at 90 deg angle. Is that the
> valve you are talking about. I'm a rookie when it comes to AC systems!
>
> Sam
>
>
> Jeff DeWitt wrote:
> > redlinescooby@hotmail.com wrote:
> > > I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> > > had an AC guy try to recover the R12, but he said it was 98% air. I'm
> > > using one of the InterDynamics kits and thought everything was going
> > > smoothly. Even though the instructions did not mention it, someone
> > > told me that I needed to remove the valve core from the low side port,
> > > since the conversion kit supplied adaptor fitting already has one. I
> > > have a valve core removal tool, but I can't seem to locate the valve
> > > core inside the fitting. After installing the adapter fittings, I
> > > tried to add some R134, but the meter is saying that it's overcharged.
> > > I don't believe that any R134 is even making it into the system.
> > > Another guy told me that I need to pull a vacuum on it. Has anyone
> > > else had this problem before?
> > >
> > > Thanks,
> > >
> > > Sam
> > >
> >
> > It's always a very good idea to throughly pump down a system if you are
> > changing the refrigerant.
> >
> > Is it possible that your gage is measuring the high side instead of the
> > low side? And you did open the valves right? I don't mean to be
> > insulting but speaking for myself I've had more trouble overlooking the
> > stupidest things that were obvious in retrospect.
> >
> > I don't recommend this but I installed AC on a vehicle that didn't have
> > it before, and used a factory evaporator designed for R12 with a modern
> > compressor (along with new everything else). This being a new install
> > it was of course full of air at normally air pressure. Not having the
> > proper equipment to pump it down and then put in just the right amount
> > of refrigerant (and just how much R-134a does a non stock AC unit in a
> > Studebaker take anyway?!) I started putting refrigerant in until the
> > unit was blowing cold and the gage was in the green, worked just fine.
> >
> > Good luck!
> >
> > Jeff DeWitt
>
07-19-2006, 05:58 PM
#20
Guest
Posts: n/a
Re: Anyone converted 4.0L from R12 to R134a?
I made some progress today. Turns out that my compressor does not have
a Schrader valve in the low pressure fitting. It just has a manual
valve. Hopefully by this time tomorrow, I'll have some colder air
blowing in my Jeep!
Sam
redlinescooby@hotmail.com wrote:
> I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> had an AC guy try to recover the R12, but he said it was 98% air. I'm
> using one of the InterDynamics kits and thought everything was going
> smoothly. Even though the instructions did not mention it, someone
> told me that I needed to remove the valve core from the low side port,
> since the conversion kit supplied adaptor fitting already has one. I
> have a valve core removal tool, but I can't seem to locate the valve
> core inside the fitting. After installing the adapter fittings, I
> tried to add some R134, but the meter is saying that it's overcharged.
> I don't believe that any R134 is even making it into the system.
> Another guy told me that I need to pull a vacuum on it. Has anyone
> else had this problem before?
>
> Thanks,
>
> Sam
a Schrader valve in the low pressure fitting. It just has a manual
valve. Hopefully by this time tomorrow, I'll have some colder air
blowing in my Jeep!
Sam
redlinescooby@hotmail.com wrote:
> I have a 91 Cherokee that I'm trying to convert from R12 to R134a. I
> had an AC guy try to recover the R12, but he said it was 98% air. I'm
> using one of the InterDynamics kits and thought everything was going
> smoothly. Even though the instructions did not mention it, someone
> told me that I needed to remove the valve core from the low side port,
> since the conversion kit supplied adaptor fitting already has one. I
> have a valve core removal tool, but I can't seem to locate the valve
> core inside the fitting. After installing the adapter fittings, I
> tried to add some R134, but the meter is saying that it's overcharged.
> I don't believe that any R134 is even making it into the system.
> Another guy told me that I need to pull a vacuum on it. Has anyone
> else had this problem before?
>
> Thanks,
>
> Sam