[SupraCentral]

Car: 1995 Supra

Symptoms: A/C blows cold, but not all the time. Sometimes it will run for an hour without a problem and will easily pull the interior temp down to 65 deg F on a 80 deg F day. Other times it will just start blowing hot air. If you look under the hood during the failure, the compressor is still engaged, but no cold air.

The A/C system diagnostics (as specified in the 95 TSRM) show no error codes stored at all.

Using a gauge on the low pressure port shows pressure in the 35 - 40 psi range when the system is running and blowing cold air. Temp gauge inserted into the center console vent shows air at 58 deg F with ambient in the 85 deg F range.

When the failure occurs the pressure gauge on the low side port drops to 0 psi, even when the compressor is running.

System contaminated? Moisture in the refrigerant freezing in the evaporator?

Any ideas?

Most cars I would just take to an A/C shop, but the thought of leaving a Supra with those guys gives me the willies...

 

[supradupaflyguy]

sounds like your thermostatic expansion valve is stuck closed

 

[SupraCentral]

sounds like your thermostatic expansion valve is stuck closed

Thanks, that lead me further into the TSRM (114 pages on A/C alone) and I found a description of my symptoms.

It states that moisture in the system is freezing the expansion valve stuck, so we are both right.

I'll have to do an evac and replace the dryer.

Thanks man!

 

[MtFujiSupra]

The 'ole TXV trick...

 

[jw1627]

I have a 1995 and need to refil the air conditioning coolant, but I am having a fitment issue. The r134a canister I bought comes with a hose and guage, but the hose is not fitting on the inlet in front of the radiator. Do I need an adapter or is there another place to fill from?

 

[yellowbeast]

it sounds like your trying to connect to the high pressure side of the system. you need to connect to the low pressure side which is closer to passenger side fender. another tip, when charging the system immerse the can of freon (not completely) in warm/hot water this will help it flow better and don't turn it upside down.

 

[jw1627]

you're probably right; i think i am trying to go through the high pressure side. i'll look for the low pressure area. thanks for the canister tip.

 

[SupraCentral]

You're damned lucky they set it up to prevent you from doing that. The high pressure side is VERY high pressure. It can blow up in your hand if you get it hooked to the high side.

 

[SupraWillis]

I have had success with removing the shims behind the pulley nut. This increases the clutch pressure on the AC, I do not know if it will effect it in the long run. My AC use to make a nast clicking noise but after removing the shims, it took care of the problem.