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A/C still won't cool after new TXV and compressor

Posted: Wed Jun 27, 2012 7:12 pm
by 91Beater
My compressor was sounding like an MRI machine which I removed and replaced with a compressor I bought from 90LegacySTI which he said is in working order.

I also replaced expansion valve with a brand new 4Seasons one. There was no signs of debris anywhere. Filter drier was also replaced as expected.

Now the compressor won't kick in for some reason, but this is to be determined later.

I jumped the compressor by directly activating by applying 12v. after of course adding the spec amount of oil and R12.

Low hangs at 25psi, high around 75psi... and here's the kicker... still no cooling.
WTF?!?!?!

Re: A/C still won't cool after new TXV and compressor

Posted: Fri Jun 29, 2012 6:17 pm
by Legacy777
It sounds like the compressor might not be working. The pressure should be MUCH higher, into the 200's or so. That or you don't have enough refrigerant in there. How much did you add?

Re: A/C still won't cool after new TXV and compressor

Posted: Fri Jun 29, 2012 7:32 pm
by 91Beater
Legacy777 wrote:It sounds like the compressor might not be working. The pressure should be MUCH higher, into the 200's or so. That or you don't have enough refrigerant in there. How much did you add?
The tag by the hood latch says 28-32oz. I added 30 oz.
Why isn't the compressor not getting activated though?

Re: A/C still won't cool after new TXV and compressor

Posted: Sat Jun 30, 2012 10:46 pm
by Legacy777
I don't know.....I'd double check all your electrical connections that may have been bumped or loosened.

Re: A/C still won't cool after new TXV and compressor

Posted: Fri Jul 20, 2012 1:28 am
by jp233
Could be the evap thermo switch or the A/C cut relay.

Also check to make sure the A/C fan will run when the compressor gets kicked on with MAX A/C and full blast on the blower.

Dang, if you had the whole system apart why didn't you convert to R134a ? Is R-12 still affordable up there, cause down here its much more pricey.

Re: A/C still won't cool after new TXV and compressor (FIXED

Posted: Sun Jul 22, 2012 9:09 pm
by 91Beater
The intermittent no kick-in issue is due to something electrical in the control box.

However, the no cool has nothing to do wit this as manual bypass by jumping the mode switch makes the compressor go, yet still didn't cool.

The problem was new-to-me compressor 90LegacySTI de
scribed to me as "known to work" wasn't working.
This was proven when another compressor was purchased and installed. System works great now.
So... finally brand new TXV
working compressor
flush & back flushed every lineset + condenser + evaporator.
New o-ring.
New schraeder valve.
I pressurized to 175 psi with CO2 and it held it
System was then vacuumed 30" of vacuum 2 hours and I turned off the valves on my gauges and let it sit for 2 hours.

It held vacuum.
Charged and it works great.

Re: A/C still won't cool after new TXV and compressor

Posted: Sun Jul 22, 2012 9:32 pm
by Legacy777
Good!

Glad you got it figured out and working.