A/C woes

I have been having some problems with my a/c since I got the jeep. It works ok, but likes to cycle on/off with some belt squeal. A while back I put some r134a into it without checking the pressure, re-tensioned the belt, etc. Well I looked at it today and appears I have overcharged it to about 100psi. It's been overcharged for a while so im guessing ive probably done some damage.

I guess I am exploring my options at this point can I take it and have the pressure relieved or am I looking at new compressor? If i replace the compressor do I have to replace the condensor/hoses? Can I replace the compressor without having to have the system vac'd or purged.

I am very mechanically inclined but cooling systems are something ive never really messed with.

first how did you check the pressure?
and if the compressor isnt making noise it should be fine
if you have a gauge then you should be able to use it to bleed some pressure off it slowly
make sure you read the can you used to add to it if it says anything about having sealer in it do not breather that crap it can kill you and most shops wont touch a system if they know you put sealer in it and the sealer will plug everything and take out the compressor

Slap some safety glasses on and push in the schrader valve. Why take it somewhere?

Don't get it on the ground. Its illegal.

4x4wagon said:

first how did you check the pressure?
and if the compressor isnt making noise it should be fine
if you have a gauge then you should be able to use it to bleed some pressure off it slowly
make sure you read the can you used to add to it if it says anything about having sealer in it do not breather that crap it can kill you and most shops wont touch a system if they know you put sealer in it and the sealer will plug everything and take out the compressor

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I checked it with on the low-side port while the jeep was off.

I am a little bit ignorant in this arena. I am assuming the pressure is supposed to be around 35psi on the low side which is the only one I have a gauge for.

The pulley seems to be make a sound that I can only describe as "rough" sounding, and it still likes to squeal every once and a while.

if the a/c has been off for 5min or more the pressure should be equal on the high side and the low side and with it off the pressure in the system should be about the same as ambient temp with the a/c on the low side should be about 20-30psi at high idle about 1000rpm depending on how hot it is

4x4wagon is right - pressure will more or less equalize without the compressor running. Always verify operating pressures while the AC is running on its highest/coldest setting. Depending on ambient temps, you should see between 30 and 50 psi on the low side. If you want specifics, I'll post the FSM chart in a bit.

charts are good to have but experience has taught me that old systems rarely follow the charts but it should be in the ballpark focus on vent temps and find someone with a gauge set so you can see the high side

4x4wagon said:

charts are good to have but experience has taught me that old systems rarely follow the charts but it should be in the ballpark focus on vent temps and find someone with a gauge set so you can see the high side

Click to expand...

so i went back today and did it properly with the jeep running and both the pressures are very close to that chart.

i still dont understand why it cycles off and on so often. the air is cold so i know its working.

My 98 cycles on and off every minute or so also. Its quite annoying.

lowrange2 said:

My 98 cycles on and off every minute or so also. Its quite annoying.

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mine does it probably 4 or 5 times in a minute. I could be wrong but it seems like it does it more when its colder.