|
09-05-2014, 08:48 PM
|
#1 |
|
Registered User
Join Date: Mar 2014
Location: Lafayette, IN
Posts: 8
|
AC Experts
I am attempting to put together the AC system on my '72 GMC Burb with factory front and rear air. I am using an aftermarket compressor, condenser, and drier. I know just enough about AC systems to cost myself a lot of money. Two questions:
1. What is the capacity (r134 and oil) for our systems? 2. When I got the truck, most of the AC stuff was under the hood, but I have read about an orifice tube. Do our trucks have them? If so, part number and where should it be? Any help would be greatly appreciated, Ryan |
|
|
|
09-05-2014, 10:24 PM
|
#2 |
|
Registered User
Join Date: Nov 2011
Location: Kirkland, WA
Posts: 343
|
Re: AC Experts
Hi, I am no expert and I too have a 72 GMC Burb and have been looking for the same type of answers so I thought I would share what I have: " There is nothing special about the rear A/C. It's a squirrel fan, core and expansion valve. The thing to look out for is the type of oil used. Your rear hoses won't like PAG oil for long. They will start breaking down. I've heard ester oil is OK" I can't seem to put my hands on the capacity but I will continue to look. The diagram below does not show an orifice tube. Hope this helps. Guy
|
|
|
|
|
09-06-2014, 07:35 PM
|
#3 |
|
Registered User
Join Date: Apr 2014
Location: Southern California
Posts: 200
|
Re: AC Experts
getting ready to go through this myself.
expansion valve is murray# 38683 (here is a place that will rebuild yours http://www.classicautoair.com/GM_OEM_Parts_Valves.html ) hoses are 1/2 inch and 13/32, 25 foot long each (Goodyear Galaxy) There is a sticker on the compressor that states 5.25 lb of R-12...holy sh#t!! |
|
|
|
|
09-08-2014, 09:37 AM
|
#4 |
|
Registered User
Join Date: Sep 2012
Location: Arlington, TN
Posts: 315
|
Re: AC Experts
My system was converted/updated years ago to 134A. When I charged it at the beginning of the summer I put in around 4lbs of 134A. 134A is typically around 75%-80% of the R-12 charge. Since perfect weight is unknown, I would suggest you charge by pressures on your gauges.
Oil is a different issue. Since oil travels throughout the system with the refrigerant it will be hard to tell you how much to put in. If you are replacing the compressor, drain the old one and measure the oil. Replace with that amount plus a few ounces if there was a leak in the system. Sorry, no perfect answer unless you start with all brand new components, hoses, etc. Hope this helps some! |
|
|
|
 |
| Bookmarks |
|
|
Linear Mode
