A/C re-install issues on my '71 GS455

Discussion in 'The Big Chill' started by rkammer, Jul 22, 2017.

  1. rkammer

    rkammer Gold Level Contributor

    Having trouble figuring this out. Now that my new motor is broken in, I'm installing the A/C system back on it. The compressor didn't fit right when I bought the car and now that I'm putting it back on, I want to resolve the problem. Here is what I have so far:
    1) Alternator/Compressor lower bracket is the welded steel one supposed to be right for '71 and up.
    2) Short water pump and pulleys 1235777 and 1235778. Belt lines up fine to alternator outer pulley.

    The problem I'm having is trying to get the compressor alignment holes to line up with the upper compressor bracket.
    1) The distance between the alignment holes on the compressor is about 7 7/8 in. where they should meet up with the upper bracket slots.
    2) The distance of the alignment holes on the bracket is about 8 1/8 in. So, there is about 1/4 in. gap instead of a snug fit. (see pics)
    3) The rear bracket on the compressor has to be bent inward to even get it to go inside the top mount alignment slot.
    4) The electrical contacts on the compressor are placed such that they will interfere with the bolt that tightens the compressor in the front slot when the pigtail is plugged in. (last pic) On other 455 motors I've seen the electrical contacts are rotated counter clockwise towards the overflow jug so they clear everything.

    So, do I 1) have the wrong top bracket or 2) the wrong compressor or 3) the correct (?) top bracket that is maybe bent or warped in some way. Based on George Nenadovich write-up the top bracket looks right for a '71 and up motor.

    This has become a real conundrum that I've been fighting for several weeks now. Any ideas?

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  2. mrolds69

    mrolds69 "The Cure"

    100_6060.JPG 100_6060.JPG It looks like the wrong compressor, because as you said the terminals are in the wrong place. I'm not sure if the rear plate on the compressor can be clocked differently to make it work. You can see where the label was and typically that would be on the top. I thought all compressors were about the same, but apparently not. I'm thinking that compressor is off a car where it was mounted on the driver side.
     
    Last edited: Jul 22, 2017
  3. rkammer

    rkammer Gold Level Contributor

    Great pic of a correctly fitting compressor. If it's your GS, any chance you could measure the distance between the inside edges of the top bracket where the compressor would slide in? That would tell me if it's my compressor or my bracket that's wrong. Thanks.

    By the way, is the pic of a '70 or a '71 or '72?
     
    Last edited: Jul 22, 2017
  4. mrolds69

    mrolds69 "The Cure"

    The pic is of my car the day it arrived, that's a 1970. It's late now, just got in, I'll measure for you in the AM.
     
  5. mrolds69

    mrolds69 "The Cure"

    The measurement inside to inside is 8". The bolt at the rear in the pic I posted is backwards, the nut should face the rear.
     
  6. rkammer

    rkammer Gold Level Contributor

    I was finally able to install the compressor using the lower and upper brackets I have. I had to use 4 washers to take up the 1/4 inch gap between the front adjusting slot the the compressor threaded hole. But, it works and the belt lines up perfectly.

    So, here's another question. There are two vacuum lines coming through the firewall. One goes to the heater control valve and the other goes to the vacuum canister on the firewall. Question is, where on the Quadrajet (or manifold) is the vacuum source for this canister? And, is it ported or full time vacuum? I've tried to find this info in the chassis manual but, all it says is "vacuum source" without saying what the source is.
     
  7. Larry Gibson

    Larry Gibson Platinum Level Contributor

    Ray, There is a nipple on the back of the carburetor that supplies vacuum to the tank.

    Larry
     
  8. rkammer

    rkammer Gold Level Contributor

    Guess I'll just take the air cleaner off and have a look. Thanks.
     

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