A/C problem

[system-f]

Everything on the A/C seems to work just fine except it doesn't cool.

When running:
High side is around 200psi
Low side shows a vacuum????

When I shut the engine off and let it sit on most systems the high side and low side pressures quickly stabilize and match, but this system when shut off the high side will show 150psi and the low side 40psi for 30mins after shut off!! I am thinking the expansion valve is stuck closed, ideas?

[tenchimuyo93]

yea sounds like a blockage somewhere in the system, id have the whole system flushed just to be safe.

[Dr_Snooz]

I had a chance to learn a little more about A/Cs this week. Your high side pressure seems low. Try throwing in some freon till you get it up to 250-275 @ 2,500 rpm on the high side. Your low side should be somewhere near zero degrees (plus or minus 4°) on the 134a scale. That might do the trick.

Apparently, when you throw a compressor, it blows garbage down the line into your expansion valve. You might consider replacing yours if you replaced a compressor at some point. It's not real hard to get to on these cars.

The cheapo can of stop leak at Wal- Mart has worked for two days now. If it holds up, I'll be recommending that to y'all as well.

[system-f]

Thank you for your response.

Try throwing in some freon till you get it up to 250-275 @ 2,500 rpm on the high side. Your low side should be somewhere near zero degrees (plus or minus 4°) on the 134a scale. That might do the trick.

After reading the manual it said 200 psi on the high side after running for 10mins. is ok. The manual also said, and I found after posting, that a vacuum on the low side is either a frozen expansion valve, faulty valve or blockage.

[2oodoor]

could be contamination causing some freezing, definatley stopped up
If you are going to pull it down again it may benefit you to take both ends off the condensor and do a good flush/check flow, it may have black death. You could spend another 100 bucks on everything else and still be a waste otherwise.
Black death, results from years of contamination, quick fixes, compressor pukes, over heating, fans not working properly etc. All the residual will lay up baked in the condensor like articulosis

[system-f]

Black death is my biggest fear.

Here are the pics of the evap. pull.



Isn't it nice that honda has an evap. assembly and you don't have to remove the dash to get it out...man this was easy.



I discharged the system from the high side going into the evap. which cause it to get a little cold with all that freon boiling off right there.

[nswst8]

Remember to do a super flush with either a/c flush or denatured alcohol.

Pag 46 is the oil they recommend for R134a in honda compressor its what I'm using.

Just remember that R-12 mineral oil and Pag don't like each other, ester is compatable with both.

[system-f]

I have pulled the condensor, evap. and all lines except two low side and one high side which can be flushed while in the vehicle. The compressor seems great turning smoothly and providing good suction. I will replace the expansion valve, drier, and flush all lines. I am not going to mess with the oil in the compressor as the car was already converted when I bought it and will probably refill with esters. Once again, this being my 3rd 3g Accord, I forgot how easy these cars were to work on.