A/C outlet Temp!

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Jul 10, 2009 | 08:41 PM

Herb

Thread Starter

Racer

Joined: Sep 2002

Posts: 337

Likes: 2

From: New Orleans La

A/C outlet Temp!

I'm curious what outlet temp your getting.
My a/c used to be really cold with the R-12 freon but my compressor went out and I replaced it and switched over to 134 freon.

All I can get is 45 degrees with the thermostat all the way down and on recirculate in the rain at 75 outside air temp.
My other vehicle will get down in the 30's at 95 outside temp and it has 134 freon.

Thanks
Herb

Jul 10, 2009 | 10:13 PM

MBDiagMan

Racer

Joined: Nov 2005

Posts: 456

Likes: 3

From: Sumner Texas

It should do better than that. What year? Is it an original R12 converted or a later model? It's always helpful with such questions to know the year model and details that are pertinent to the question being asked.

Have you put gauges on the system?

Jul 10, 2009 | 10:27 PM

Herb

Thread Starter

Racer

Joined: Sep 2002

Posts: 337

Likes: 2

From: New Orleans La

It's a 93 LT1 with a new same as stock compressor converted to 134.

It has been vacuumed down twice.

Jul 10, 2009 | 10:40 PM

Stanley Distribution

Melting Slicks

Joined: May 2009

Posts: 3,223

Likes: 0

A system designed for R12 but using R134a will always have higher temps than it did using R12. Usually it's not much, so it's not a big deal.

Your other car that cools fine with R134a was probably a setup designed to use it from the factory correct? Usually OEM's design the A/C system with more capacity to deal with the R134a being less efficient.

Jul 11, 2009 | 05:49 AM

Herb

Thread Starter

Racer

Joined: Sep 2002

Posts: 337

Likes: 2

From: New Orleans La

Yes, your right! The other vehicle was designed for 134.
Thanks
Herb

Jul 11, 2009 | 06:00 AM

coupeguy2001

Le Mans Master

Joined: Sep 2006

Posts: 6,050

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From: Phoenix AZ

2021 C4 of the Year - Modified Finalist

I have an 86 that I converted to 134. I too cannot see temps below 45. I did change out my blower motor, and now I get more volume. Checker/kragen has the motors for around $25. the car really cools now

Jul 11, 2009 | 06:46 AM

Crzyfrlss1

Instructor

Joined: Mar 2009

Posts: 126

Likes: 1

From: Newington CT

R134 will almost never be as cold as R12, it's just the way it is.

But one trick that usually works is to undercharge the system by 15% but still, most of the time I never see temps below 40-42.

Unless I'm working on school bus AC units which are 300k btu or bigger and I see 28 degrees out of those with 134a.

Jul 11, 2009 | 12:39 PM

SunCr

Le Mans Master

Joined: Dec 2000

Posts: 7,839

Likes: 22

From: San Diego, Ca

You need an accurate thermomter first. Do you know what a steady 38 degrees does to your knuckles? There are limitations with what any mobile a/c can and cannot do and the one thing none can do is drop the evaporator below freezing. Get your operating pressures so that you have some idea as to what the Evaporator temperature is. Find out how low it can go by pulling the Blower Motor Connector and noting the pressure the compressor cuts out at. With that info, we might be able to help you make it better.