AC service valves
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Junior Member
Joined: Jul 2010
Posts: 41
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From: Rio Grande Valley
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I have done extensive searching and reading and have not found this specific topic. I have a 1990 Cherokee Sport with the 4.0. The AC compressor has these weird valves on it from the factory. I need to replace, repair or eliminate those valves to get my AC working.
CF Veteran

Joined: Feb 2015
Posts: 1,528
Likes: 2
From: North Carolina
Year: 1993
Model: Cherokee
Engine: 4.0
looks like you have the r12 system but somebody already retrofitted it to r134a, the blue and red cap are your high and low pressure ports. Since it's an older system, it also has valves to open and close the high/low pressure port. Those valves are the little stud looking things with the square head on them sticking out. Looks like they are in the open position. Hope this helps
CF Veteran

Joined: Feb 2015
Posts: 1,528
Likes: 2
From: North Carolina
Year: 1993
Model: Cherokee
Engine: 4.0
Also, here is a pic of the valves I'm talking about, with the square heads. This is the only pic I could find. Some cars open turning right, some turning left. Just depends. On my 93 jeep, the service ports are on the back of the compressor and to open them, I got to turn right, and left is to tighten. Yours may be opposite.
Seasoned Member
Joined: Dec 2014
Posts: 419
Likes: 12
From: Oregon (Wetside)
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0l
You don't say why you need to eliminate them, but I think you need them with this style of compressor/ head. Here is link to explain their function. They also make your compressor serviceable without losing the refrigerant.
http://wiki.amcevolution.com/index.p...Service_Valves
http://wiki.amcevolution.com/index.p...Service_Valves
Senior Member



Joined: Sep 2015
Posts: 940
Likes: 72
From: Abysmo, NJ
Year: 1999
Model: Cherokee
Engine: 4.0
AMC used these service valves on their cars from Rambler days into the 1980s, and apparently on early XJs as well. No need to eliminate them unless stuck or leaking. I use a 1/4" drive socket with an allen wrench to operate the valves. (On the cars I've worked on, the 1/4" square end fits the service valve stem perfectly.)
As the diagram that Oswalla provided indicates, for normal AC operation turn the valves all the way counterclockwise to "back-seat" them. Turn clockwise a few turns to position them in the middle for servicing and charging the system. Normally you would not "front-seat" the valves (full clockwise) unless replacing the compressor. This position permits the compressor to be removed without discharging the system, aside from the small amount in the compressor itself.
As the diagram that Oswalla provided indicates, for normal AC operation turn the valves all the way counterclockwise to "back-seat" them. Turn clockwise a few turns to position them in the middle for servicing and charging the system. Normally you would not "front-seat" the valves (full clockwise) unless replacing the compressor. This position permits the compressor to be removed without discharging the system, aside from the small amount in the compressor itself.
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CF Veteran

Joined: Feb 2015
Posts: 1,528
Likes: 2
From: North Carolina
Year: 1993
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Jan 2015
Posts: 2,152
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From: Minnesota
Year: 1999
Model: Cherokee
Engine: 4.0L
Originally Posted by 93XJeeper
looks like somebody already did, it's got r134 retrofit kit on it.
Thread Starter
Junior Member
Joined: Jul 2010
Posts: 41
Likes: 0
From: Rio Grande Valley
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
You don't say why you need to eliminate them, but I think you need them with this style of compressor/ head. Here is link to explain their function. They also make your compressor serviceable without losing the refrigerant.
http://wiki.amcevolution.com/index.p...Service_Valves
http://wiki.amcevolution.com/index.p...Service_Valves
Seasoned Member
Joined: Dec 2014
Posts: 419
Likes: 12
From: Oregon (Wetside)
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0l
That should work, just have to have a way to get gauges on and fill. Another option is to get a set from wrecking yard. U-pull-it yard would be cheapest
Seasoned Member
Joined: Dec 2014
Posts: 419
Likes: 12
From: Oregon (Wetside)
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0l
Check this out, this might be what your looking for. Not the search term I would of used to find it.
FORD BACK-SEAT ROTOLOCK YORK R210L A/C
COMPRESSOR SUCTION FITTING
http://www.acpartsguys.com/service_valves
or
http://www.ebay.com/itm/BACK-SEAT-RO...-/280963786818
and 1 more
http://thepartguy.com/ac-hosesMustangCougar.html
FORD BACK-SEAT ROTOLOCK YORK R210L A/C
COMPRESSOR SUCTION FITTING
http://www.acpartsguys.com/service_valves
or
http://www.ebay.com/itm/BACK-SEAT-RO...-/280963786818
and 1 more
http://thepartguy.com/ac-hosesMustangCougar.html
Last edited by Oswalla; Jun 22, 2016 at 01:38 PM.
Thread Starter
Junior Member
Joined: Jul 2010
Posts: 41
Likes: 0
From: Rio Grande Valley
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Check this out, this might be what your looking for. Not the search term I would of used to find it.
FORD BACK-SEAT ROTOLOCK YORK R210L A/C
COMPRESSOR SUCTION FITTING
http://www.acpartsguys.com/service_valves
or
http://www.ebay.com/itm/BACK-SEAT-RO...-/280963786818
and 1 more
http://thepartguy.com/ac-hosesMustangCougar.html
FORD BACK-SEAT ROTOLOCK YORK R210L A/C
COMPRESSOR SUCTION FITTING
http://www.acpartsguys.com/service_valves
or
http://www.ebay.com/itm/BACK-SEAT-RO...-/280963786818
and 1 more
http://thepartguy.com/ac-hosesMustangCougar.html
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