I recently replaced the AC system on my 1991 camaro.

Here's what was done:

New AC Delco Compressor
New Condenser
New Accumulator (and r134a fitting)
New AC Lines (that attach to the compressor and go to the condenser and accumulator)
New VOV orifice valve
New green O-rings on all fittings

Blew the high pressure line and evaporater lines old oil out
Added 2 ounces of PAG 100 oil to compressor
Added 2 ounces of PAG 100 oil to condenser
Added 2 ounces of PAG 100 oil to accumulator
Added 2 ounces of PAG 100 oil to evaporator


Then I tried pulling a vacuum on the system and realized I had the wrong "o-ring" for the high pressure side of the compressor. Replaced that with the correct size.

Tried pullling a vacuum again, but my manifold gauge set keep going to 0 psi as soon as I tried closing off the valves. Also, they would only bring the psi down to about -8 instead of the required -28. I never got to pull a good vacuum. I figured the gauges were shot because they were giving my a lot of trouble, and I thought for the pressure to rise this quickly, there would be a very large leak.

I figured I'd add some refrigerant in with dye to try and find the leak, but nothing seemed to leak out.

I then filled the system up with refrigerant (r134a) and it has blown very cool for about a week with seemingly very little to possibly no leak.



HOWEVER, this last Friday, my compressor started smoking at the clutch!

After checking it out, my compressor is getting VERY hot to the touch under operation. The clutch is basically shot.


I used my manifold gauges to test pressure and the low side is about 35psi and the high side is around 240psi when running (its in the low 80s when i did this.)

The compressor clutch will stop slightly, then struggle and spark if I give the car RPM when running (to test the pressure under load.) If not doing this, the compressor stays on (constant, no cycling.)


With all this happening, the air is still blowing very cold from the vents, but the compressor/clutch is about to go.





I have a new compressor, condenser, and accumulator on their way. I'm going to buy new oil and get the refrigerant taken car of too. I think I'm going to stick with a regular orifice tube this time (maybe the red ford ones I've heard of.)




My questions are,

Can anyone see what I may have done inherently wrong (besides not being able to pull a good vacuum, it was a hotter dry day so I don't think there should be much to any moisture in the system)?


How hot are these compressor supposed to get? ( I read as hot as the valve cover somewhere, but those were very hot too and it could burn my hand if I let it. My compressor could burn me quite easily if I wasn't careful)


Should I not use a VOV valve? (I actually had to reuse my old orifice tubes o-ring because this valve wouldn't fit in the evap line. I cleaned the old o-ring off with new oil and put it on the VOV valve and it fit snugg in place)


Could the hot compressor be a sign of bad pressure switches (either on the accumulator or compressor?)


Could I have gotten a bad AC compressor?





Please anyone with knowledge on this subject help me out. I've done AC on three other vehicles that were empty before, and those are still running well years later, I don't know what is going wrong on this car.

Thanks for your time!

 

Sounds like you didn't put enough oil in the compressor, you want the bulk of the oil in it. 6 oz. in the compressor 2 oz. in the accumulator and none in the evap. or cond..... I never had a issue while in the business 20+ years do'n it this way.

If you can't pull a vacuum and your gauges are suspect, update to a new set. Proper functioning gauges is a must, since retiring from the business my high dollar leak detector took a dump. I didn't want to spend the bux on another high dollar one for occasional jobs, I opted for a chepo (under 20 bux) on Ebay that works just fine.

Lastly,

The last job I did on my Buick, I installed the Ford blue orfice tube everyone raved about helping the system cool better. What I found is, it didn't make any difference at all..... I believe their claim is from them adding a little extra or a little less (over charged before) refrigerant then claiming the Ford orfice helped..... IMO, stick with a GM replacement orfice and know it's right for the system.....

 

Thank you for the reply! I haven't gotten the orifice tube yet so I'll go grab the correct one when I'm ready to work on the system again.

The instructions on the compressor said to pour 2 ounces of oil in the compressor, and then gave a chart of how much oil to pour in the other parts of the system, so I followed that chart. It did seem weird to me that it only called for 2 ounces in the compressor because I know they usually take more (like the 6 ounces you mentioned) so I will make sure to do that next time.

I did find some cheap gauges on craigslist I will probably pick up pretty soon too. My gauges seemed to function last night, but I had issues with them previously. It's too bad also because I spent 100 dollars on them a while back.

 

Just an update.

I got all the new A/C stuff in and flushed the components I didn't replace.

This time, I used a 96 Ford Crown Vic orifice tube (it was orange) and it fit in the evap tube much better.

I also put 6 ounces of PAG 100 oil in the compressor, and 2 in the accumulator instead of spreading it through the system.

My manifold gauges ended up being fine, but my hoses were leaking, so I purchased all new hoses.

With this, the system stayed at -29" of hg for over a day after I did the intial vacuuming. For the initial vacuuming, I ran the vacuum pump for roughly 2 minute intervals and then held vacuum about 10 different times (ran vacuum, closed gauges to keep vacuum for about 15 minutes, then ran vacuum again.) I did this because I didn't want to keep my air compressor from continuously running.

Anyways, after doing that, I ended up initially flooding the high pressure hose with liquid r134a (with car off on initial fill, then closed the high pressure line. I read to do this with a new empty system to help cycle oil on initial start up), then opened the low pressure line and let the gas fill with the Car on and A/C on max.

I filled the system with as close to 40 ounces as I could (3.5 cans 12 ounces cans, taking into account losses when changing cans and purging lines.)



My new compressor does not get too hot now (during charging before it was full it was getting hot still), and is cooling very well. The compressor still gets quite warm when it is on, but I can safety hold my hand on the compressor without risk of burning.

It must have been the combination of my manifold gauges not letting me vacuum/add enough refrigerant last time, along with potentially faulty new compressor than made it seize within one week.


Hopefully this thread can help someone in the future when doing A/C.

 

Glad you got it working and very glad it didn't catch fire while driving!