Hi all! I'm working on my 1998 Jimmy again. This time I'm working on the A/C. I had it working just fine last summer but then the compressor decided to leak from the seal in the middle over the winter. No biggie—I got the system working well last summer so I figured I could do it again. It has been more of a challenge this year and I could really use some help.

When I started working on the A/C a couple weeks ago the system was completely discharged and wouldn't hold vacuum. I started by replacing the compressor with a remanufactured unit. I put in the required amount of oil and turned the shaft to move the oil through the compressor. When I went to replace the accumulator the outlet pipe on the evaporator twisted right off the evaporator which led to a new evaporator. Since I had to replace the evaporator I took the opportunity to flush the condenser while it was disconnected and the system was open. I put it all back together with the reman compressor, new evaporator, new variable orifice tube, and new PAG 150 oil in the appropriate places to spec.

I put the vacuum pump on it and vacuumed it down to a little over 29" hg and it held for an hour. I started charging the system with R-134a and it only took part of two 12oz cans before it stopped taking refrigerant. It was enough to get the compressor to start cycling but not enough to get any cooling. When the compressor started cycling it was about 80°F outside. The clutch engaged at 42psi on the low side and kicked off at 22psi. The high side cycled between 80 and 100psi.

What do I need to do to get the proper amount of refrigerant in the system? It won't take any more. I tried revving the engine up over 2000 RPM but that didn't get the compressor to suck in any more refrigerant.

 

You need to replace the receiver/dryer, then put it on a vacuum and see if it holds, and then continue to vacuum the system for another half hour. Then recharge the system.

 

Toby have you tried flipping the can upside down and back and forth. These can be charged with the can completely upside down. You can also stick the can in a pot of warm water. The small cans get really cold and the vapor pressure changes to the point that the liquid will not change to a gas,

 

When I replaced the compressor I installed a brand new accumulator. Are you saying that brand new one is bad?

 

I haven't tried flipping the can. I was worried that the refrigerant would come out as a liquid and then try to go through the compressor and damage it. I'll try that next week. I'm headed out to the coast this weekend and A/C won't be necessary out there as I doubt it will be over 70°F.

 

Do not turn the can upside down.Yes, this will make it take the Freon easier, but you are taking a chance of putting liquid in the compressor and locking it up. Only vapor should ever go to the compressor. If it doesn't take more Freon, you have another problem.

 

 

Success! I did two things to get more refrigerant into the Jimmy: I jumped the compressor to run the low side pressure down to about 15psi to draw more refrigerant in from the can and I also put the refrigerant cans in warm water. Both of those things allowed me to get all 28oz into the system. It blows nice and cold now which was especially appreciated over this past weekend when I took my family to Eastern Washington for a little vacation.

Thanks all!