Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

1991 Suburban with R134a retrofit gone bad

RockyMtnMan on Mon July 04, 2011 6:07 PM User is offline

Year: 1991
Make: GMC
Model: Suburban
Engine Size: 5.7l
Refrigerant Type: R134a
Country of Origin: United States

I got this GMC Suburban (V2500 with 350) about 10 years ago, and it came to me with a marbles
rattling compressor, dual A/C with R12. The owner had recharged the A/C the previous week,
but it had already leaked out by the time I test drove it (and doomed myself to it).

My then-mechanic in CA said it was a good time to convert to R134, since the compressor was
getting swapped out for a new unit; he did a minimal flush job (probably didn't pull the expansion
valve in back, nor the oriffice tube in front), and the resulting A/C performance was underwhelming.

He did screw on the retrofit charging adapters; is that a reversible change?

A few weeks later, the charge had leaked out, and he swapped out the larger of the two rear
A/C lines for a fresh factory hose; he did not change O-rings elsewhere, nor convert to "barrier"
hoses. Now the 'Burb will hold a charge for about a summer, so there's either a very slow leak
somewhere, or I'm dealing with porous hoses, or some other gotcha. I have the system
discharged now (rear motor fan is shot), so I could dig in and do some serious flushing,
then recharge with R134a and look for leaks.

Questions for the forum:

Does this seem like a reasonable plan? I'm wondering if the conversion simply wasn't done to the
standards recommended by this forum (especially the flushing). Maybe I should replace the stock
hoses with "barrier hoses" and replace all O-rings on principle, are these even available for a vehicle
this old (aside from a custom hose fabrication effort)?

Should I consider converting back to R12? Seems these 'Big as a House' vehicles don't do well with
the retrofit. I'd want to be sure I was leak-free before taking the $$$ plunge. I'm very happy with my
other vehicles I've left at R12 (1983 Mercedes, 1987 Shelby CSX).

Should I convert to a parallel flow condensor? Even with R12, my older Big Block Suburban didn't do
well at idle, even after I replaced the fan clutch.

Any pointers to a GOOD A/C shop in the Denver/Boulder area of Colorado?

-------------------------
'91 Suburban with dueling AC

TRB on Mon July 04, 2011 7:33 PM User is offlineView users profile

Max-Air in Denver has been around a while.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

chris142 on Thu July 07, 2011 12:11 AM User is offline

I've had no luck with making an older Suburban work on R134a. They just wont work. The thing is going to hold 5.25 lbs of R12 though.

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.