Need A/C help

[wjtowne]

Ok, I need some A/C help.

It started last summer. My A/C wasn't working, so I took it to the Ford dealer. They checked for leaks and said there weren't any and then recharged the system. All was good for about 3 months. Then it stopped working again. It was near winter, so I left it until this summer.

I went to the store and purchases a DIY recharge kit with gage. So, I recharged the system. Here is what I did.

Hooked up the gage to the low side valve. I was getting about 8 psi so there was still a little freon in the system. I turned on the engine and set the A/C to max. I begain recharging. Pretty soon the compressor would cycle on and off. When the low side got to about 50 psi the compressor would turn on until it dropped to about 20 (I think) then cycle off. I continued to charge until the low side stayed at about 30 psi with the compressor engaged. I was getting Ice cold air.

Question 1. When I turn off the A/C the low side pressure would rise to over 80 psi. Is this normal?

Question 2. when I remove the gage. The freon is leaking out through the schrader valve. Did I overcharge and blow the schrader valve seal?

Question 3. If the large rise in pressure on the low side with the compressor off is normal, I probably had a leak at the schader valve the whole time and the dealer didn't find it. Maybe it won't leak with a vacuum, but will with pressure. Can I replace just the schrader valve or do I need a whole piece that has the valve (not sure what part that is)?

Thanks,
Willie

 

[audiomax]

i am by no means a A/C specialist, but I have replaced just the schrader valve on vehicle before. As far as the low side pressure, it is normal for it to rise when the A/C is not in use, Sounds like the valve has been leaking, and you lost the freon, which caused the system to quit working. Replace the valve, chrge and see if it doesnt take care of it.

 

[my98nnj]

1) When the system isn't running, the pressures will equalize.
2) You found your leak, replace the valve.

 

[Papa]

That is why those little caps are so important, it is not uncommon for valves to leak. The same is true of tires.

 

[wjtowne]

I was able to tighten up the existing valve and the AC has worked now for a month or so.

BTW. It was hard to find a valve stem tool that was long enought to reach the stem to tighten it.

 

[koda2000]

i believe others have answered your questions. the long a/c valve tool is available at autozone (and no doubt other auto parts stores) for a few bucks. it's very common for these valves to leak, especially the charging/low side. if you've lost the little blue and red plastic valve covers, or if their o-ring/gaskets are missing or damaged, get replacements and make sure they're on tight.