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88 Cherokee a/c line thing

90xj06

NAXJA Forum User
Location
Peabody, MA
1988 Cherokee 4.0. suction line has a bump in it. Is it a muffler? I have reason to believe what ever it is has gotten clogged as I'm frosting up on it. I just replaced my dryer and noticed this. Also there is some kind of valve thing that connects to the dryer does it also have a name?
 
I took some closed cell foam and wrapped it, secured with tie wraps. The wrap extends beyond the metal fittings.

How's the 152 working for you?
 
its been working great. did some adjusting to the evaporator temperature switch to cycle off at ~40 and back on at ~50.

but i got a hole in my condenser over the winter and after replacing that im having some issues. just slowly going through everything. i have a noisy compressor so i may swap in a 91+ compressor setup with r134 ports for ease of service.
 
You'll need to go later than '92 - mine used R12 from the factory (been converted to 134 for something like 12 years now, though).
 
The ac brackets are different from Renix to HO. I think the '92 bracket will mount to the Renix block if you can source one.

When mine seized a while back, I looked at an "upgrade", rather than a conversion. After all the tradeoffs, decided to remain with year correct parts. At the time, although still more expensive, R-12 was easily acquired (yes, I'm 609 certified). I didn't care for the alternatives under SNAP at the time. I still have 2 cans of R-12 left.
 
Normally I would leave it period correct. But the compressor is starting to make noise while idleing.

There are a few at my local yard I could source brackets and parts. I might just go with a new compressor and hoses. Essentially replacing everything but the evaporator.

I also have 2 cans of R-12 and I just can't give them up or use them.
 
I look forward to trying the multi pass and see if it makes any difference.

Also, I seem to recall hearing somewhere that R12 hoses aren't perfectly compatible with R134a, that they leak down over time. I have one conversion going which I have to add a little to once a year, I wonder if that isn't it?
 
That doesn't ring a bell with me. The only time I've lost refrigerant in my 134-converted R12 system is when something truly failed (condensor rot, or rusted-out liquid line). No recollection of having leakdown.
 
R152a is awesome. So far so good on my conversion on another vehicle.

I'm not sure what the bump is, but IIRC R134a introduction was 94 or 95.

Also, did you flush the old mineral oil out and add ester oil while doing your R152a conversion? You need to - mineral oil won't flow with R152a, gotta use ester oil, and it might be why your compressor is making noise now. If you open the system to replace the compressor and see "black death" black gunk or silvery metal debris, it's time to flush everything extremely carefully and replace anything you can't flush.
 
...replace anything you can't flush.

This should be read as remove dash, remove HVAC cabinet, and replace evaporator. Then change the accumulator/dryer. The original condenser is single pass and can be flushed.

This is why people complain about the price of a shop replacing a compressor that trashed. It includes all of the above or the shrapnel will eventually circulate to an inevitable physical disagreement with the new unit, resulting in another failure in short order.
 
Recently replaced the condenser and dryer. Clean as a whistle no gunk or particles. The compressor had been making noise from the time I got the jeep.
 
Excellent, glad to hear it - it's nice to be wrong sometimes.

This should be read as remove dash, remove HVAC cabinet, and replace evaporator. Then change the accumulator/dryer. The original condenser is single pass and can be flushed.

This is why people complain about the price of a shop replacing a compressor that trashed. It includes all of the above or the shrapnel will eventually circulate to an inevitable physical disagreement with the new unit, resulting in another failure in short order.

Yep. On my wife's Roadmaster I had to replace the compressor because it fragged (damn Harrison R4s... it's what they do best), along with the receiver/dryer, capillary tube, evaporator, and condenser. I was able to find a junkyard liquid line to flush carefully with a lot of acetone and some pipe cleaners, and the suction line and liquid line from the receiver/dryer to the evap I was able to clean out as well. Wasn't fun, but the AC blows ice cold now w/ R152a and POE oil, a year or two later, so I am happy with it.

I debated installing a filter before the compressor but couldn't find one that wasn't effectively a piece of window screening. There's already one of those in the system (part of the capillary tube) and it did nothing to help last time, so I didn't see the point. Nearly used a filter assembly intended for a residential AC unit, but wasn't sure it was compatible with the refrigerant or oil.
 
WTH is R-152a? Are they switching from 134a now to something new?

I still drive an 85 diesel jeep LOL. trying to catch up :)

R152a is awesome. So far so good on my conversion on another vehicle.

I'm not sure what the bump is, but IIRC R134a introduction was 94 or 95.

Also, did you flush the old mineral oil out and add ester oil while doing your R152a conversion? You need to - mineral oil won't flow with R152a, gotta use ester oil, and it might be why your compressor is making noise now. If you open the system to replace the compressor and see "black death" black gunk or silvery metal debris, it's time to flush everything extremely carefully and replace anything you can't flush.
 
R12 is dichlorodifluoromethane. Used in AC until the early 90s and as "canned air duster" and those little pocket airhorns until the late 80s or early 90s.
R134a is 1,1,1,2-tetrafluoroethane. Used as AC until the present day and as "canned air duster" and those little pocket airhorns until the mid 00s, iirc.
R152a is 1,1-difluoroethane. Used as an R12 substitute (with the proper lubrication oil) by nerds like me, and currently used as "canned air duster" and those little pocket airhorns. (seeing a pattern yet? :roll:)

If you go to your local chinesium dealership (Harbor Freight) and find the Ultra Duster cans on the shelf - they are R152a with bitterant added. Currently priced at $4.99 for a 10oz can. My wife's Roadmaster AC system actually has 3 cans of that in it... I didn't feel like finding a vendor for "R152a" as a refrigerant. Been working great for a year or two now.

The best part? It works just as well as R12 (R134a requires larger condenser and evaporator coils to provide the same cooling) and has a much lower GWP and ODP than most other currently available refrigerants. AND it's cheaper.
 
Very informative, I had not run across that yet. I may try it one day. What gauge pressures and outdoor temps did you use to charge/fill it?

But thermometer :rolleyes: ? LOL

I have one more upgrade job on my bucket list, may just try it. What oil did you use? The one PAG??? (IIRC) The one that works with remaining mineral oil so you do not need to do a pure/complete oil swap/flush?

R12 is dichlorodifluoromethane. Used in AC until the early 90s and as "canned air duster" and those little pocket airhorns until the late 80s or early 90s.
R134a is 1,1,1,2-tetrafluoroethane. Used as AC until the present day and as "canned air duster" and those little pocket airhorns until the mid 00s, iirc.
R152a is 1,1-difluoroethane. Used as an R12 substitute (with the proper lubrication oil) by nerds like me, and currently used as "canned air duster" and those little pocket airhorns. (seeing a pattern yet? :roll:)

If you go to your local chinesium dealership (Harbor Freight) and find the Ultra Duster cans on the shelf - they are R152a with bitterant added. Currently priced at $4.99 for a 10oz can. My wife's Roadmaster AC system actually has 3 cans of that in it... I didn't feel like finding a vendor for "R152a" as a refrigerant. Been working great for a year or two now.

The best part? It works just as well as R12 (R134a requires larger condenser and evaporator coils to provide the same cooling) and has a much lower GWP and ODP than most other currently available refrigerants. AND it's cheaper.
 
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