Automotive Air Conditioning Information Forum (Archives)

Provided by

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

Archive Home

Search Auto AC Forum Archives

AC system restoration

Joeyg on Mon May 11, 2009 11:46 AM User is offline

Year: 1984
Make: Chevrolet
Model: K5 Blazer
Engine Size: 350
Refrigerant Type: R-134?
Country of Origin: United States

I am getting to close to breaking open my AC system and replace the components. Right now, it's blowing, but the air is barely cool. The history on this vehicle is that I bought it about 24 years ago. I have had in in the shop many times over that 24 year period. It was converted over to R-134 ten or so years ago. I had a new compressor put on about 6 years ago, but they either did not clean the system or forgot to put oil in it, a year later, the valves started rattling in the compressor.

I live in Houston, Texas. The land of high heat and even higher humidity.
I plan on replacing the compressor with a new unit, new hoses, new dryer, and make some other changes, then refill with R-134.

1.) I have read that I should go back with a "variable Orifice tube" I see what looks like one on Rock auto pn 1550122, but the description says nothing about it being a variable unit. Can someone verify that it is, or provide me with a dealer for one.

2.) Pressure switch. I read I should find an adjustable one or at least find one configured for R-134. Any help with this on my 1984 K5 Blazer would be helpful.

3.) I want to add some additional electric cooling fans in front of the condensor. One to kick on thermostatically, one to kick on when the AC is turned on. I read the ones with the mounting "pins" that go thru the condensor end up screwing up your condensor, had anybody had that experience, or should I try to fabricate a mount for the fans that would attach to my core support.

4.) Should I go with cleaning my old condensor or go with a new one. My experience with foriegn parts has been stick with the old one if it still works. Too many times I have gotten a new part from China only to find out it was bad right out of the box.

5.) Any other tips or tricks would be appeciated.


1984 Chev K5 Blazer

Chick on Mon May 11, 2009 4:35 PM User is offlineView users profile

First, the forum you found is also the "best" place to buy your parts...
I would not use the variable O tube, but if you do, you can get that here too. (I prefer the Ford blue O tube in GM retrofits) I would change the condenser, as your compressor was a black death compressor, and it may be to far gone to flush..
Check out the Tips and FAQ section of this board to find help with flushing, vac/recharge etc..

Here is a link to 1984 Blazer replacement parts and you will see they also have the condenser.. hope this helps..

I would also use the BVA auto 100 oil in your retrofit..Just my personal choice..

Email: Chick


Freedoms just another word for nothing left to lose

bohica2xo on Mon May 11, 2009 5:06 PM User is offline

Your best bet is to start from the same place the OEM did 24 years ago. Flush the evaporator to bare metal, and replace everything from the firewall foreward.

I show a 6mm piccolo condensor for that truck, and I would put a new one in it. New dryer, new hoses, new compressor - great plan. You will have an OEM quality system again.

Your cycling switch is adjustable. If you pull the connector off of it, the screw is down between the two pins in the switch body. Once you get the system running, you can adjust the switch for minimum acceptable evaporator temperature (this varies by vehicle & climate).

Pass on the variable OT. Just snake oil, and something else to fail. Use either the stock orifice, or the ford blue tube as Chick has suggested.

Condensors are not designed for mounting things to. Using an electric fan is good, but mount it to the vehicle. Keep your engine driven fan, and replace the clutch if it has more than 50k miles on it. Fan clutches wear out slowly, and can be junk without you knowing it. It should ROAR on a cold start, and after a long idle cycle with the A/C on. Be sure the fan shroud is in place, and that no air is bypassing the condensor.


"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

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.