ac pump

[tylermckee]

My 72 gmc k10 350 is missing the ac pump but has everything else, was wondering what year/model pumps i can use. Also might need the brackets. Another thing is what does it take to convert to the r134a does anything need to be changed out or would i just do the conversion for how much of the new gas is needed and fill my system with it. im assuming mine doesnt have anything in it as the pump is gone.

[LUV2XCLR8]

2 THE BOARD FROM WEST 10-UH-C

Only part of your question I can halfway answer is yes,
you can convert and go to 134, will have to replace, if
it is not new, the cylinder looking thing in the grill area

[smokekiki]

Here is a link to an a/c board.Do a search under, POA valve adjustment and r134 conversion. http://www.autoacforum.com/index.cfm...=Yes&forumid=1

[BobbyK]

If all you need is a compressor and as you said "all the other stuff is there" I'd stay with the R-12.
Once the compressors on and connected,get the system leak tested,flushed,install a new receiver/dryer(cylinder looking thing behind the grill),replace the O-rings and get it evacuated and charged.

R-12 is ALOT more expensive but if your not going to maintain the system yourself,meaning buying the proper tools to do it right,and have a qualified A/C shop maintain it you might as well keep the R-12.

Prob cheaper in the long run for you.

Now if your going to do the work yourself,I'd say sure...switch to R134.
Things that WILL need to be changed for the 134 conversion are:
-receiver/dryer with disicant that is R-134 compatible.


-POA elliminator installed or adjust the orig. POA valve.
POA eliminator

orig. POA valve.



-Flush system to get all the R-12 oil out.(it's not compatible with R-134)
-new Parallel flow condensor.The orig. condensor will work but you won't get adequate cooling with it.I saw at least a 5-7 deg. drop in cab temps after I changed to a parallel flow condensor.
parallel flow condensor

[jtminton]

What do you mean "adjust the POA valve"?

[chickenwing]

TylerMckee, Hope you don;t mind if I post a follow up question.

BobbyK, I have the poa elim.. Do you know what vehicle I can get the biggest parallel flow condensor that will fit? My factory condensor was junk anyway and have been slowly gathering up the bits and pieces to finish this.

Also, going with an R-4 compressor. Anything I should watch out for?

Edit: How can you identify a parallel flow condesor?

[BobbyK]

It needs to be adjusted down.R-134 runs at a different "super-heat" preasure.
The stock POA is set at 29psi for R-12.
Re-adjust to 26psi for R-134 in order to get the most out of the POA set-up.

Again inadequate cooling will be the effect of not adjusting the POA and running R-134.

Here is the adjusting screw you'd need to mess with.


Here's looking inside the POA.


Here is how it's adjusted useing compressed air.


All this info can be had at the A/C forum link SMOKEKIKI provided.

[smokekiki]

Here is a pretty big new one http://www.ackits.com/merchant2/merc..._Code=12-0511A

[smokekiki]

Here is the link to the adjusting procedure.http://www.autoacforum.com/messagevi...&threadid=7567

[BobbyK]

Chickenwing.
Well A/C kit's has generic Parallel flow ones at a REAL good price.
I got the biggest one that I could fit in the orig. condensor position.The center grill support needs to be taken into consideration when deciding on a size.

I'll have to measure mine as I can't remember the size off hand.

ID parallel flow condensor?Well they are alway aluminium and they look like the one in my pic.Most new cars run them.I think the Camaro and Firebird condensors may fit our trucks but not sure on that.

I hear therebuilt R-4 compressors have a high failure rate.Best to get new if possible.

[BobbyK]

Here's an opinion on ther R4 compressor.Taken from the A/C kits forum.

http://www.autoacforum.com/messagevi...AR_MSGDBTABLE=

[BobbyK]

my Parallel flow condensor measures 14"x26".That's 14" top to bottom and 26" from mounting rail to mounting rail.The actual cooling fins only measure 23" across.

Here is my exact condensor I bought,price and size.
http://www.ackits.com/merchant2/merc..._Code=12-0438C

[chickenwing]

BobbyK and Smokekiki, thanks for the info.

BobbyK, 1 more question what did you achieve for ambient temp drop? Oh and thanks for that condensor link! I was thinking $200+! That's why I was thinking used wrecking yard stuff. I should be able to afford what you have when I get the green light to do my A/C.

[BobbyK]

Well It was 87 the other day and my A/C was just as cold as my wifes 2004 Grand Cherokee.
I haven't measured vent temps recently but when I did the conversion about 1 year ago I was getting roughly 42-43 deg out the vents!
It's awsome!