Search found 6 matches

by alpine44
Fri Jul 12, 2019 10:38 am
Forum: Automotive Air Conditioning Forum
Topic: Building a custom R134a system for 1985 square body Blazer
Replies: 9
Views: 8435

Re: Building a custom R134a system for 1985 square body Blazer

Any positive displacement pump is variable output by changing the RPM The electrically commutated PMDC motors are fairly efficient over a broad speed range. So there is no need to use a variable displacement compressor with a variable speed motor. A little Sanden with a direct drive (no belt losses...
by alpine44
Thu Jul 11, 2019 1:43 pm
Forum: Automotive Air Conditioning Forum
Topic: Building a custom R134a system for 1985 square body Blazer
Replies: 9
Views: 8435

Re: Building a custom R134a system for 1985 square body Blazer

Use a similar sized valve - forgot about the external equalization. Unless you live in some remote spot, there is an industrial hose shop somewhere nearby. The Aeroquip stuff works well, but you need to use the whole system - hose, fittings & tool Some odd MVAC fittings are not available from A...
by alpine44
Tue Jul 09, 2019 1:33 pm
Forum: Automotive Air Conditioning Forum
Topic: Building a custom R134a system for 1985 square body Blazer
Replies: 9
Views: 8435

Re: Building a custom R134a system for 1985 square body Blazer

Use the TXV for the 1972 GM line - C20 / Suburban / Impala etc all used the same valve. Go ahead and use the accumulator along with a Receiver in the liquid line. I do this on TXV conversions, you get a second dryer. Add 1.5 to 2.0 ounces of oil for the added dessicant & the puddle in the botto...
by alpine44
Mon Jul 08, 2019 7:08 am
Forum: Automotive Air Conditioning Forum
Topic: Building a custom R134a system for 1985 square body Blazer
Replies: 9
Views: 8435

Re: Building a custom R134a system for 1985 square body Blazer

Found answers to some of my previous questions. It looks like 4 Seasons #38911 would be a candidate for a solenoid valve to control the liquid flow to the rear evaporator TXV. Also figured out the electrical wiring. 12V for compressor clutch from dash panel via trinary switch on receiver to clutch. ...
by alpine44
Mon Jul 08, 2019 6:44 am
Forum: Automotive Air Conditioning Forum
Topic: Building a custom R134a system for 1985 square body Blazer
Replies: 9
Views: 8435

Re: Building a custom R134a system for 1985 square body Blazer

If you use a TXV, you need to use a drier and not an accumulator. The locations in the system are totally in different places. I know that I need a receiver/drier between condenser outlet and TXV. I ordered a receiver/drier with the condenser and will install it somewhere near it. However, the orig...
by alpine44
Sun Jul 07, 2019 8:51 am
Forum: Automotive Air Conditioning Forum
Topic: Building a custom R134a system for 1985 square body Blazer
Replies: 9
Views: 8435

Building a custom R134a system for 1985 square body Blazer

Greetings to everyone from a new member. I am in the process of adding A/C to my 1985 M1009, the military version of a Chevy Blazer. This is my first foray into vehicle A/C after repairing or re-engineering almost everything else on cars. So far I have installed the blower/evaporator unit, the air b...