Took a while but I should have all the parts to replace everything except the evap. by Friday. Thanks for the advise, seems "Synthetic PAG" works for both R12 and R134 so I'll use it so a change in the future will not be difficult. I've ordered a new condenser that might be parallel from looking at the pictures but won't know till it gets here. "JeepAir" had liquid lines that were hard to find for 89. (Same as 90.)
89 XJ A/C repair advise?
- Thread starter b5blue
- Start date
FYI I found info that states R134 will indeed destroy the container screen inside an old R12 dryer using XH-5 desiccant. A dryer using XH-9 is safe for both R12 and R134. (The mindset being rearward/forward compatible for new parts.)
I found the best pricing for a NEW compressor on RockAuto, 150.62 shipped. (Includes new clutch.)
I found the best pricing for a NEW compressor on RockAuto, 150.62 shipped. (Includes new clutch.)
Ecomike
NAXJA# 2091
- Location
- MilkyWay Galaxy
WOWZER, $48 is a great deal!!!! Also I see you are doing your home work and finding the right stuff, congrats. I was told it was the desiccant itself that turned to sludge and clogged the screen, Either way you got the scoop on the best drier to use. Good work. Not bad on the compressor price. Let us know how well it works and operating pressures please.
Something to consider
I upgraded from R12 to R134 on my '90 XJ and found that you can get everything to work "pretty well" but unless you change your evaporator out as well, it will be sub-optimal. In the 100+ degree Texas heat I have to run it at max and it still won't get comfortable but it will blow cold and will keep you from passing out from heat exhaustion ;-).
With this setup you will never be able to achieve perfect pressures. To make this work as well as possible you will find that you will need to find the best balance between the high pressure line and the low pressure line. If I recall correctly, the High Pressure line will need to be a little higher than "perfect" while the Low Pressure line will need to be a little lower than "perfect". The reason for this is that the R134 evaporator has a larger outlet port (which is why the expansion valve is different). When you use the R12 evaporator the smaller outlet port constrains the gas expansion and thus, you won't get the maximum efficiency. You will only see this with a proper set of gauges but this is also why people report that when you use the cheap low side gauge only, it is best to under-fill it a bit.
Don't get me wrong, it will work pretty well with the old evaporator but it won't be able to handle really hot days as well as it would if you had the proper evaporator.
Pressures are a function of ambient temperatures so it will change depending on the outside temperature but you can find charts online that will help you understand what to aim for.
HTH
I upgraded from R12 to R134 on my '90 XJ and found that you can get everything to work "pretty well" but unless you change your evaporator out as well, it will be sub-optimal. In the 100+ degree Texas heat I have to run it at max and it still won't get comfortable but it will blow cold and will keep you from passing out from heat exhaustion ;-).
With this setup you will never be able to achieve perfect pressures. To make this work as well as possible you will find that you will need to find the best balance between the high pressure line and the low pressure line. If I recall correctly, the High Pressure line will need to be a little higher than "perfect" while the Low Pressure line will need to be a little lower than "perfect". The reason for this is that the R134 evaporator has a larger outlet port (which is why the expansion valve is different). When you use the R12 evaporator the smaller outlet port constrains the gas expansion and thus, you won't get the maximum efficiency. You will only see this with a proper set of gauges but this is also why people report that when you use the cheap low side gauge only, it is best to under-fill it a bit.
Don't get me wrong, it will work pretty well with the old evaporator but it won't be able to handle really hot days as well as it would if you had the proper evaporator.
Pressures are a function of ambient temperatures so it will change depending on the outside temperature but you can find charts online that will help you understand what to aim for.
HTH
Last edited:
Ecomike
NAXJA# 2091
- Location
- MilkyWay Galaxy
I have done three 85-89 XJ upgrades between 2006 and 2008, still all working perfectly and the ONLY thing I did not replace was the evaporator, and I got the exit grill temps down to about 40 F, with about 25-30 psi low side and about 220 psi high side (it was about 310 high side before I replaced the condenser with a 97 parallel flow style). I have never ever had a vehicle in 42 years here that cooled well enough in Houston summers with 90% humidity and 95-105 F days unless it was on Max AC, including dozens of new rental cars.
I'm by Tampa Bay so have been miserable with feels like temps around 100. My 50's Jeeps all had well placed large vents that caught bunches of air, the Cherokee's give you no venting really. Modern cars all block any way of venting so even on nice days it still gets hot inside.
I pulled up to the house last week and the XJ started stumbling and shaking. So there was the last part needed sitting at my door but now I've got something to fix before repairing A/C! My hope is the R12 with new parts holds up many years and the parallel flow condenser helps make up for the actual smaller size these Jeep use. (For the job they do they look undersized)
I pulled up to the house last week and the XJ started stumbling and shaking. So there was the last part needed sitting at my door but now I've got something to fix before repairing A/C! My hope is the R12 with new parts holds up many years and the parallel flow condenser helps make up for the actual smaller size these Jeep use. (For the job they do they look undersized)
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