Retrofit from R12 to 134A

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Apr 25, 2009 | 07:01 PM

JeepingDan

Thread Starter

CF Veteran

Joined: Apr 2009

Posts: 18,786

Likes: 14

From: CT.

Year: 88

Model: Comanche (MJ)

Engine: 4.0 HO

Retrofit from R12 to 134A

I fitted my '89' from R12 to 134A 36oz 6oz mineral oil. I had to reposition the low side valve just so I could get the gauges on.
Did a deep vac for 1 hour to make sure any air or old R12 was completely sucked out of the system.

Next Like stated above filled with 6 oz of mineral oil and 36 oz 134A
The low side should read around 40 psi and high side 150 psi are good numbers.

Now I can drive my renix comfortably in the hot summer.

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Last edited by JeepingDan; May 7, 2011 at 04:58 PM.

Apr 25, 2009 | 09:41 PM

4.3L XJ

CF Veteran

Joined: Aug 2008

Posts: 6,588

Likes: 495

From: Chico, CA

Year: 1986

Model: Cherokee

Engine: 4.3L with headers and full 3" exhaust system

Hey guy, looks like you know something about this. I was going to post a new thread on charging with a sight glass, which some of us have. It won't let me post anything in the tech section for some reason. You wanna do it?

Apr 25, 2009 | 10:07 PM

solderjunkie

Seasoned Member

Joined: Apr 2009

Posts: 470

Likes: 4

From: Nashville TN

Model: Cherokee

Good job!

We have been pushing Freeze 12 at work... non-flammable and has a similar volumetric pressure to R12. The manufacturer says the Freeze 12 is compatible with mineral-based oils in R12 systems.

A little hint... mine has R134A. I don't trust the Freeze 12 yet.