Need help on A/C
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Joined: Feb 2006
Posts: 78
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From: In The Hills S.C.
Need help on A/C
I have been replacing a/c system on 74 (previous owner had removed it). System has two low pressure connections (one on hose manifold connected to compressor and one on side of VIR) with one high pressure connector on liquid return to condensor. According to GM manual you connect at VIR (low side) and liquid return to condensor (high side). When I went to hook up manifold gauge lines to ports , blue hose adapter will fit low side but red hose has same size adapter which is larger than high side port I purchased manifold gauges off craigs list and they were listed as a R12 set. I thought (Blue/yellow low side) was one size and (red high side) was smaller. QUESTION: Do I not have manifold set for R12 and/or do I need an adapter?
Have searched internet for adapter and can"t locate one. So I am puzzled.
Have searched internet for adapter and can"t locate one. So I am puzzled.
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
You can use either low side port. I surprised you can access the one on the VIR due to lack of room. As for the adapter for the high side, this should be what you need. Your hose port should be ok to use. GM made the high side port smaller to alert mechanics and keep them from thinking it was the low side port. 
http://www.ackits.com/merchant.mvc?S...Category_Code=
http://www.ackits.com/merchant.mvc?S...Category_Code=
Last edited by Jud Chapin; Feb 12, 2008 at 08:48 AM.
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
BTW, wood worker, you might give NAPA a call. I think that's where I got mine although it's been quite a few years now. Most parts houses don't carry any R12 related items any more.
