Since the early 70's Jeep has been putting in a proportioning valve in
all and the load weight (height) sensing valve in some Jeeps to prevent
rear wheel lock up.

If the rear wheels lock when you are not expecting it, you can do 360's
faster than you can blink.

I personally would get that valve back into the system or add a few sand
bags to the box to give it some weight so the wheels don't lock as easy.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"Stephen R. Conrad" wrote:
>
> I just noticed that the brake lines starting with the proportioning valve
> have been reworked on my recently acquired MJ. I haven't traced all the
> altered lines but for one thing the height sensing valve has been bypassed.
> Maybe this explains wht the dash light is always illuminated. (I fixed that
> probem : ) )The brakes generally work OK but a light foot is required to
> keep the rears from locking up. My question is: In how big of a hurry do I
> need to be to return to the original configuration? This of course presumes
> that the height sensing valve can be salvaged or replaced. Thanks.
>
> 86 MJ longbed, auto, 2.5L, 155K
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.596 / Virus Database: 379 - Release Date: 2/26/2004

 

Since the early 70's Jeep has been putting in a proportioning valve in
all and the load weight (height) sensing valve in some Jeeps to prevent
rear wheel lock up.

If the rear wheels lock when you are not expecting it, you can do 360's
faster than you can blink.

I personally would get that valve back into the system or add a few sand
bags to the box to give it some weight so the wheels don't lock as easy.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"Stephen R. Conrad" wrote:
>
> I just noticed that the brake lines starting with the proportioning valve
> have been reworked on my recently acquired MJ. I haven't traced all the
> altered lines but for one thing the height sensing valve has been bypassed.
> Maybe this explains wht the dash light is always illuminated. (I fixed that
> probem : ) )The brakes generally work OK but a light foot is required to
> keep the rears from locking up. My question is: In how big of a hurry do I
> need to be to return to the original configuration? This of course presumes
> that the height sensing valve can be salvaged or replaced. Thanks.
>
> 86 MJ longbed, auto, 2.5L, 155K
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.596 / Virus Database: 379 - Release Date: 2/26/2004

 

Since the early 70's Jeep has been putting in a proportioning valve in
all and the load weight (height) sensing valve in some Jeeps to prevent
rear wheel lock up.

If the rear wheels lock when you are not expecting it, you can do 360's
faster than you can blink.

I personally would get that valve back into the system or add a few sand
bags to the box to give it some weight so the wheels don't lock as easy.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"Stephen R. Conrad" wrote:
>
> I just noticed that the brake lines starting with the proportioning valve
> have been reworked on my recently acquired MJ. I haven't traced all the
> altered lines but for one thing the height sensing valve has been bypassed.
> Maybe this explains wht the dash light is always illuminated. (I fixed that
> probem : ) )The brakes generally work OK but a light foot is required to
> keep the rears from locking up. My question is: In how big of a hurry do I
> need to be to return to the original configuration? This of course presumes
> that the height sensing valve can be salvaged or replaced. Thanks.
>
> 86 MJ longbed, auto, 2.5L, 155K
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.596 / Virus Database: 379 - Release Date: 2/26/2004

 

Hi Stephen,
The Pump that's part of the master cylinder and looks like:
http://www.----------.com/88XJabsPump.jpg has been replaced with a
regular non ABS that works, right? If so, then for sure replace the
proportioning valve with one from a regular brake lines, because the
fittings the stock ABS uses, the best way is to rob an old XJ. And of
course the thingie with the lever on it doesn't need to be hooked up
because it's not needed to shut off the ABS any longer, when loaded.
God Bless America, ßill O|||||||O
mailto:--------------------

"Stephen R. Conrad" wrote:
>
> Thanks for the replies.
>
> I did not mention in the first post that there are also air shocks on the
> rear. Wouldn't this fool a working height sensing valve? I don't know in
> what order these changes were made. I had broken spring leafs replaced 2 on
> right 1 on left and a rusted out shackle on the left.
>
> Bill, I don't think that this one ever had abs.
>
> Will, The old height sensing valve is still on the vehicle but the link to
> the diff is gone. Everything is very rusty under there. The old brake lines
> just under the proportioning valve (located directly under the master
> cylinder are still there, but have been cut away and new lines installed. I
> have not completely followed the new routing, but one of the outlets from
> the proportioning valve is not being used. The one directly on the bottom of
> the valve.
>
> "Stephen R. Conrad" <sconradpt@yahoo.com> wrote in message
> news:c2dvsh$1rgp40$1@ID-129890.news.uni-berlin.de...
> > I just noticed that the brake lines starting with the proportioning valve
> > have been reworked on my recently acquired MJ. I haven't traced all the
> > altered lines but for one thing the height sensing valve has been
> bypassed.
> > Maybe this explains wht the dash light is always illuminated. (I fixed
> that
> > probem : ) )The brakes generally work OK but a light foot is required to
> > keep the rears from locking up. My question is: In how big of a hurry do I
> > need to be to return to the original configuration? This of course
> presumes
> > that the height sensing valve can be salvaged or replaced. Thanks.
> >
> > 86 MJ longbed, auto, 2.5L, 155K
> >
> >
> > ---
> > Outgoing mail is certified Virus Free.
> > Checked by AVG anti-virus system (http://www.grisoft.com).
> > Version: 6.0.596 / Virus Database: 379 - Release Date: 2/26/2004
> >
> >
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.596 / Virus Database: 379 - Release Date: 2/26/2004

 

Hi Stephen,
The Pump that's part of the master cylinder and looks like:
http://www.----------.com/88XJabsPump.jpg has been replaced with a
regular non ABS that works, right? If so, then for sure replace the
proportioning valve with one from a regular brake lines, because the
fittings the stock ABS uses, the best way is to rob an old XJ. And of
course the thingie with the lever on it doesn't need to be hooked up
because it's not needed to shut off the ABS any longer, when loaded.
God Bless America, ßill O|||||||O
mailto:--------------------

"Stephen R. Conrad" wrote:
>
> Thanks for the replies.
>
> I did not mention in the first post that there are also air shocks on the
> rear. Wouldn't this fool a working height sensing valve? I don't know in
> what order these changes were made. I had broken spring leafs replaced 2 on
> right 1 on left and a rusted out shackle on the left.
>
> Bill, I don't think that this one ever had abs.
>
> Will, The old height sensing valve is still on the vehicle but the link to
> the diff is gone. Everything is very rusty under there. The old brake lines
> just under the proportioning valve (located directly under the master
> cylinder are still there, but have been cut away and new lines installed. I
> have not completely followed the new routing, but one of the outlets from
> the proportioning valve is not being used. The one directly on the bottom of
> the valve.
>
> "Stephen R. Conrad" <sconradpt@yahoo.com> wrote in message
> news:c2dvsh$1rgp40$1@ID-129890.news.uni-berlin.de...
> > I just noticed that the brake lines starting with the proportioning valve
> > have been reworked on my recently acquired MJ. I haven't traced all the
> > altered lines but for one thing the height sensing valve has been
> bypassed.
> > Maybe this explains wht the dash light is always illuminated. (I fixed
> that
> > probem : ) )The brakes generally work OK but a light foot is required to
> > keep the rears from locking up. My question is: In how big of a hurry do I
> > need to be to return to the original configuration? This of course
> presumes
> > that the height sensing valve can be salvaged or replaced. Thanks.
> >
> > 86 MJ longbed, auto, 2.5L, 155K
> >
> >
> > ---
> > Outgoing mail is certified Virus Free.
> > Checked by AVG anti-virus system (http://www.grisoft.com).
> > Version: 6.0.596 / Virus Database: 379 - Release Date: 2/26/2004
> >
> >
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.596 / Virus Database: 379 - Release Date: 2/26/2004

 

Hi Stephen,
The Pump that's part of the master cylinder and looks like:
http://www.----------.com/88XJabsPump.jpg has been replaced with a
regular non ABS that works, right? If so, then for sure replace the
proportioning valve with one from a regular brake lines, because the
fittings the stock ABS uses, the best way is to rob an old XJ. And of
course the thingie with the lever on it doesn't need to be hooked up
because it's not needed to shut off the ABS any longer, when loaded.
God Bless America, ßill O|||||||O
mailto:--------------------

"Stephen R. Conrad" wrote:
>
> Thanks for the replies.
>
> I did not mention in the first post that there are also air shocks on the
> rear. Wouldn't this fool a working height sensing valve? I don't know in
> what order these changes were made. I had broken spring leafs replaced 2 on
> right 1 on left and a rusted out shackle on the left.
>
> Bill, I don't think that this one ever had abs.
>
> Will, The old height sensing valve is still on the vehicle but the link to
> the diff is gone. Everything is very rusty under there. The old brake lines
> just under the proportioning valve (located directly under the master
> cylinder are still there, but have been cut away and new lines installed. I
> have not completely followed the new routing, but one of the outlets from
> the proportioning valve is not being used. The one directly on the bottom of
> the valve.
>
> "Stephen R. Conrad" <sconradpt@yahoo.com> wrote in message
> news:c2dvsh$1rgp40$1@ID-129890.news.uni-berlin.de...
> > I just noticed that the brake lines starting with the proportioning valve
> > have been reworked on my recently acquired MJ. I haven't traced all the
> > altered lines but for one thing the height sensing valve has been
> bypassed.
> > Maybe this explains wht the dash light is always illuminated. (I fixed
> that
> > probem : ) )The brakes generally work OK but a light foot is required to
> > keep the rears from locking up. My question is: In how big of a hurry do I
> > need to be to return to the original configuration? This of course
> presumes
> > that the height sensing valve can be salvaged or replaced. Thanks.
> >
> > 86 MJ longbed, auto, 2.5L, 155K
> >
> >
> > ---
> > Outgoing mail is certified Virus Free.
> > Checked by AVG anti-virus system (http://www.grisoft.com).
> > Version: 6.0.596 / Virus Database: 379 - Release Date: 2/26/2004
> >
> >
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.596 / Virus Database: 379 - Release Date: 2/26/2004