I bought a '00 Sport over the winter, and just recently realized the AC doesn't work. We're going to have a heat wave in Boston over the next few days so I thought today would be a good day to get the a/c looked at. I brought it to my shop, because I noticed that the compressor kept cycling on and off every second or two. They thought the refrigerant might be low, but after testing it for leaks and recharging it, they got a code (1491 I think) for the radiator fan relay. They said the fan was working fine, but they replaced the relay anyway, but the compressor still wouldn't work. They recommended replacing the compressor, and quoted about $750 for everything. I told them I couldn't afford it, paid the diagnostic fee, and they evacuated the system. They said if the compressor gets replaced, they can refill it and it should be fine.

I'm pretty mechanically inclined (replaced water pump, plugs, etc.) so today I picked up a new compressor, accumulator, and the refrigerant oil. Once I replace everything I'll take it back to my shop and have it recharged, saving me over $300. I just want to make sure I have everything right before I start. I tried searching but couldn't find anything concrete on the forum. I have the Jeep factory manual, which has great detail, but I was wondering if anyone else had tips/suggestions. This is my plan:

1. Remove serp belt.
2. Disconnect and remove the old accumulator and compressor.
3. Install new accumulator and fill w/ 4 ounces of PAG-100, R134a oil
4. Install compressor, filling with oil and rotating per manufacturers instructions to distribute oil.

It seems pretty straightforward, and the system should be clean since the shop evacuated it for about 45 minutes before I picked up the truck. Once I install the new parts, I can drive it a mile or so to the shop without doing any damage, right? Will exposing the accumulator to air for a few hours before the fill damage it in any way? Sorry if these are dumb questions, it's been a while since I worked on ac. Any thoughts appreciated, thanks!

 

You want to flush that system entirely, or get ready to buy another compressor in the very near future. What if you replace the compressor, system is charged builds pressure and say the evaporator is shot?

 

When you say flush, do you mean with a cleaner, or just compressed air? I was at advance earlier to pick up some parts and they were out of the cleaner I was considering getting (http://bit.ly/qjI5v3).

I figured if compressed air could make it through, then there isn't a clog/blockage. Do you recommend the cleaner? In either case, is there a recommendation on the pressure of the compressed air? Definitely don't want to burst anything.

Thanks,
A

 

Definitely flush the evap and cond....we poured a bottle of a/c flush in each and blew with 40-50 psi compressed air. Get a new liquid line as it has a built-in orifice tube....always a good idea to replace that along with the accumulator/dryer. How about the hose/manifold assembly.....at least flush the old one. Turn the new compressor upside down to empty any oil. We poured 1/2 of the oil into the accumulator and the other 1/2 into the new compressor, buttoned it all up, took it to a pro to pull vacuum and charge with refrigerant.....13 mos later, still have 34F at the center vents.

 

I did my compressor 2 summers ago. REALLY easy job. Not sure of the differences (if any) but Ive got a '99. Basically remove ONLY what needs to be removed. Replace with new compressor (Mine was $220 from a Jeep supply place, cant remember which right now) and attach everything. Then I took it to the shop and told them my compressor went and I had to replace it, can you guys do everything to it that needs to be done to get it cold again. They flushed and vacuumed the system and charged it for like $120ish. So, for around $350 I had everything done. Cheap, no. The cheapest you can get out of it. Definitely.

 

Thanks for the info. I have access to a small compressor so I can try flushing it and then cleaning it out. That's what my plan is w/ the oil, so it looks like that should fix the issue. I'm not sure how they verified that the compressor is the issue, but I trust my mechanic has he hasn't steered me wrong before. I'll check w/ him tomorrow to confirm all this.

I can drive to the shop after installing the new parts as long as there is oil present, right?

 

Does the compressor try to start? You may want to check the a/c compressor clutch air gap first and see if it is within spec. That can be done with the compressor on the vehicle and the a/c system intact.

 

Currently the compressor does nothing because the system is evacuated. I believe that when at vacuum, a pressure switch does not allow the compressor to run.

However, this morning before the shop took a look at it, the compressor would try to turn on, but after about 1-2 seconds it would putter out. The compressor would continue to cycle like this when the AC was set to on.

 

So today I replaced the accumulator and compressor, which was pretty straightforward. I brought it to my shop, and they performed a leak test and charged the system, and when they turned they AC on, it worked fine.

However, when they simulated continuous driving, by running at a steady idle of 1500 rpm, the compressor never shut off and continued to build a high pressure and eventually bursting the refrigerant out of the relief valve in the compressor.

They think it's just a pressure switch on the high side not telling the compressor to shut off once it gets to the right pressure (about 300 psi I think). This sounds plausible, but I wasn't sure if something else might be the problem.

Any thoughts?