GM - AC questions

Yay!Gurrr

Yay!Gurrr

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Mar 17, 2005
Location
N. N. Raleigh, NC
ok, Im trying to fix the A/C on my truck and I have a few questions.

If i jumper the low pressure switch the pump turns on and works. And it does make cold air. (I didnt leave it on long, im assuming its not working for a reason). So I replaced that (low pressure) switch with a new one.

I've tried charging it with the DIY kit. (Note this is a factory R134 setup) says i got the correct amount of pressure 15-18 psi and it seems to hold the pressure fine.

What should i do next?

Was reading its possible its been charged with too much oil ?
(I know previous owner tried charging it also) If so how do i get that out ?

Anyone got a vacume pump thing to 'evacuate' the system? Should i replace anythign else? Id like to keep it <$100 is possible.


HELP !!
-mike
 
If your around this weekend get up with me, ride by the house and we'll see what we come up with. I'm about 10 miles north of wake forest.
 
while getting married last week i had time to catch up with my cousin who was an auto mechanic and still does work on the side. He said change the oriface filter tube thing and draw some vacume and recharge.. (he did sugest changing the acumulator/dryer) he said that with 190k and asuming a few cans of a/c sealer junk its probaly pluged and reaching max PSI as soon as the pump kicks on..

So next question is:

anyone use one of these venturi vacume pumps ?

http://cgi.ebay.com/ebaymotors/R134...ryZ43989QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

looks like its uses shop air pressure to draw vacume. The guage set was just somthign i was thinking would be good to have...

any ideas?

thanks - mike
 
Can you say 45deg out of the cold vent !!!!!!!! outside temp was 84 so thats a solid 40deg drop..

Finally got around to fixing the A/C on the truck. I barrowed a guage set and vacume pump. The deep vacume seemed to do the trick. 15min on the pump and another 15 to make sure it held.. I had read that the right orafice valve could make a good system great but damn, definilty surprised me... So I replace the $6 orafice valve, and the $30 hi/low switch which wasn't really bad. I think that my hi/low switch connector was part of the problem as i had to squeez the little socket things a bit tighter to get a better grip on the plug. As the pump was cutting in/out for no reason.. That and some juice and the truck is good to go...
 
Did you replace the orifice valve with a stock part number for your truck or did you use a different part number? I have ok AC, but I think the metering may need to be increased.
 
It was the $6 generic brand that was in stock at Advance Auto :)

Just looked it up for my truck it calls for this one...
Factory Air Expansion Valve / Orifice Tube
Part Number: 38638

That orafice valve is also a filter screen which is why it was sugested to me to changed mine out.. But after some additoinal homework it seems the wrong one can hurt the cooling process...

Also my truck is stock R134 not a retrofit..
 
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