Re: Re: TJ A/C Issues
 

SnoMan writes:

> Never happen, the low pressure cutout switch would kick in long before
> you even came close to negative pressure.

One would hope so, but the OP said that was faulty.

A leak means you have no pressure sooner or later with the system off.
If it is turned on and runs (faulty low-pressure switch), it will
certainly have negative pressure (vs ambient) on the suction side, and a
leak in that half will pull in air and moisture. Even without running,
a leaky system admits air and moisture slowly after the refrigerant is
gone. Consider that a system that fails due to a refrigerant leak will
often go for months or years before being repaired, so the dessicant
will be saturated, just due to amibent temperature and barometric
cycling.

A/C technicians often have a superstition that their vacuum pump removes
moisture from a contaminated system, including regenerating the
dessicant. Not true. You should replace the dessicant (which means the
whole accumulator on a TJ) if there's any chance it was open to the air,
leaky for a long time, or otherwise compromised.

If you want to regenerate dessicant, you have to bake it. Room
temperature vacuum is not enough.

Re: Re: TJ A/C Issues
 

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9953E90899CC6someconundrum@216.196.97.131. ..
....
>
> If you want to regenerate dessicant, you have to bake it. Room
> temperature vacuum is not enough.

Bake it? Done this? Reliable?

Thanks.

Earle



--
Posted via a free Usenet account from http://www.teranews.com

Re: Re: TJ A/C Issues
 

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9953E90899CC6someconundrum@216.196.97.131. ..
....
>
> If you want to regenerate dessicant, you have to bake it. Room
> temperature vacuum is not enough.

Bake it? Done this? Reliable?

Thanks.

Earle



--
Posted via a free Usenet account from http://www.teranews.com

Re: Re: TJ A/C Issues
 

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9953E90899CC6someconundrum@216.196.97.131. ..
....
>
> If you want to regenerate dessicant, you have to bake it. Room
> temperature vacuum is not enough.

Bake it? Done this? Reliable?

Thanks.

Earle



--
Posted via a free Usenet account from http://www.teranews.com

Re: Re: TJ A/C Issues
 

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9953E90899CC6someconundrum@216.196.97.131. ..
....
>
> If you want to regenerate dessicant, you have to bake it. Room
> temperature vacuum is not enough.

Bake it? Done this? Reliable?

Thanks.

Earle



--
Posted via a free Usenet account from http://www.teranews.com

Re: TJ A/C Issues
 

On Jun 18, 10:54 pm, Richard J Kinch <k...@truetex.com> wrote:
> SnoMan writes:
> > Never happen, the low pressure cutout switch would kick in long before
> > you even came close to negative pressure.
>
> One would hope so, but the OP said that was faulty.
>
> A leak means you have no pressure sooner or later with the system off.
> If it is turned on and runs (faulty low-pressure switch), it will
> certainly have negative pressure (vs ambient) on the suction side, and a
> leak in that half will pull in air and moisture. Even without running,
> a leaky system admits air and moisture slowly after the refrigerant is
> gone. Consider that a system that fails due to a refrigerant leak will
> often go for months or years before being repaired, so the dessicant
> will be saturated, just due to amibent temperature and barometric
> cycling.
>
> A/C technicians often have a superstition that their vacuum pump removes
> moisture from a contaminated system, including regenerating the
> dessicant. Not true. You should replace the dessicant (which means the
> whole accumulator on a TJ) if there's any chance it was open to the air,
> leaky for a long time, or otherwise compromised.
>
> If you want to regenerate dessicant, you have to bake it. Room
> temperature vacuum is not enough.

Low pressure switch is fine, accumulator was replaced again under
warranty along with the compressor to avoid the issue you mentioned.

Re: TJ A/C Issues
 

On Jun 18, 10:54 pm, Richard J Kinch <k...@truetex.com> wrote:
> SnoMan writes:
> > Never happen, the low pressure cutout switch would kick in long before
> > you even came close to negative pressure.
>
> One would hope so, but the OP said that was faulty.
>
> A leak means you have no pressure sooner or later with the system off.
> If it is turned on and runs (faulty low-pressure switch), it will
> certainly have negative pressure (vs ambient) on the suction side, and a
> leak in that half will pull in air and moisture. Even without running,
> a leaky system admits air and moisture slowly after the refrigerant is
> gone. Consider that a system that fails due to a refrigerant leak will
> often go for months or years before being repaired, so the dessicant
> will be saturated, just due to amibent temperature and barometric
> cycling.
>
> A/C technicians often have a superstition that their vacuum pump removes
> moisture from a contaminated system, including regenerating the
> dessicant. Not true. You should replace the dessicant (which means the
> whole accumulator on a TJ) if there's any chance it was open to the air,
> leaky for a long time, or otherwise compromised.
>
> If you want to regenerate dessicant, you have to bake it. Room
> temperature vacuum is not enough.

Low pressure switch is fine, accumulator was replaced again under
warranty along with the compressor to avoid the issue you mentioned.

Re: TJ A/C Issues
 

On Jun 18, 10:54 pm, Richard J Kinch <k...@truetex.com> wrote:
> SnoMan writes:
> > Never happen, the low pressure cutout switch would kick in long before
> > you even came close to negative pressure.
>
> One would hope so, but the OP said that was faulty.
>
> A leak means you have no pressure sooner or later with the system off.
> If it is turned on and runs (faulty low-pressure switch), it will
> certainly have negative pressure (vs ambient) on the suction side, and a
> leak in that half will pull in air and moisture. Even without running,
> a leaky system admits air and moisture slowly after the refrigerant is
> gone. Consider that a system that fails due to a refrigerant leak will
> often go for months or years before being repaired, so the dessicant
> will be saturated, just due to amibent temperature and barometric
> cycling.
>
> A/C technicians often have a superstition that their vacuum pump removes
> moisture from a contaminated system, including regenerating the
> dessicant. Not true. You should replace the dessicant (which means the
> whole accumulator on a TJ) if there's any chance it was open to the air,
> leaky for a long time, or otherwise compromised.
>
> If you want to regenerate dessicant, you have to bake it. Room
> temperature vacuum is not enough.

Low pressure switch is fine, accumulator was replaced again under
warranty along with the compressor to avoid the issue you mentioned.

Re: TJ A/C Issues
 

On Jun 18, 10:54 pm, Richard J Kinch <k...@truetex.com> wrote:
> SnoMan writes:
> > Never happen, the low pressure cutout switch would kick in long before
> > you even came close to negative pressure.
>
> One would hope so, but the OP said that was faulty.
>
> A leak means you have no pressure sooner or later with the system off.
> If it is turned on and runs (faulty low-pressure switch), it will
> certainly have negative pressure (vs ambient) on the suction side, and a
> leak in that half will pull in air and moisture. Even without running,
> a leaky system admits air and moisture slowly after the refrigerant is
> gone. Consider that a system that fails due to a refrigerant leak will
> often go for months or years before being repaired, so the dessicant
> will be saturated, just due to amibent temperature and barometric
> cycling.
>
> A/C technicians often have a superstition that their vacuum pump removes
> moisture from a contaminated system, including regenerating the
> dessicant. Not true. You should replace the dessicant (which means the
> whole accumulator on a TJ) if there's any chance it was open to the air,
> leaky for a long time, or otherwise compromised.
>
> If you want to regenerate dessicant, you have to bake it. Room
> temperature vacuum is not enough.

Low pressure switch is fine, accumulator was replaced again under
warranty along with the compressor to avoid the issue you mentioned.

Re: Re: TJ A/C Issues
 

Earle Horton writes:

>> If you want to regenerate dessicant, you have to bake it. Room
>> temperature vacuum is not enough.
>
> Bake it? Done this? Reliable?

Standard procedure for silica gel or molecular sieve dessicants.