Vintage Air Gen V (5) or replace existing compressor, etc., for 1987 R20 Suburban?

Carbed or TBi? If FI, GM put the computer behind the glovebox, right where VA puts their system. TBI computer will need relocation.

I bought my compressor from Rock Auto for my 88 R20 454 GMB part # 9712214 and it works OK but would not buy one of those again. Someone on here a while back said that if you run a parallel flow condenser and a blue orifice it will work great. Dont know though. Looks like I have a neighbor here! I live in the Chesapeake Va area. I have a vintage air in my other 88 and it works great as long as the air is blowing on you but it will not cool the truck interior. I was going to have a special hose made for hooking up the rear unit, add some oil and freon and see if I could get it to do the job but have not got around to that yet. Thats #23 on the list.

Knuck55 said:

I bought my compressor from Rock Auto for my 88 R20 454 GMB part # 9712214 and it works OK but would not buy one of those again. Someone on here a while back said that if you run a parallel flow condenser and a blue orifice it will work great. Dont know though. Looks like I have a neighbor here! I live in the Chesapeake Va area. I have a vintage air in my other 88 and it works great as long as the air is blowing on you but it will not cool the truck interior. I was going to have a special hose made for hooking up the rear unit, add some oil and freon and see if I could get it to do the job but have not got around to that yet. Thats #23 on the list.

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Thanks. Tunnel traffic is great, isn’t it. Lol……

I need to figure out if I need a different orifice tube to keep the rear ac happy. I thought I read use white, but maybe that was just for trucks and not suburbans? It had a white one in it when I bought it.

I think I may block off the rear ac lines for now and worry about flushing the rear and fixing the barely functional and dragging rear fan next year.

Too many things to get dialed in on this truck, plus the two dozen other projects and equipment that always needs love at my gf’s farm. I just need ac/defrost and heat at a functional level so I don’t freeze and have a non-fogged windshield this winter for now.

I followed this post - https://www.gmsquarebody.com/threads/r4-to-sanden-whith-stock-ac-lines-for-serpantine.22437/

it was suburban specific. I also added a small pusher fan that helps a little, but the stock clutch fan really moves a lot of air on its own.

the rear fan probably has had the mounting bracket come loose or somebody put it back together a little out of alignment and it is dragging. it's pretty straight forward to dive into it and adjust the position or fix a bracket.

the service manual (see Reference Library) shows how it all comes apart and goes back together.

gmbellew said:

I followed this post - it was suburban specific. I also added a small pusher fan that helps a little, but the stock clutch fan really moves a lot of air on its own.

the rear fan probably has had the mounting bracket come loose or somebody put it back together a little out of alignment and it is dragging. it's pretty straight forward to dive into it and adjust the position or fix a bracket.

the service manual (see Reference Library) shows how it all comes apart and goes back together.

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My rear bracket is all out of sorts. The plastic that everything screws to has gotten so brittle that its just flaking apart. Right now theres just a lot of zip-ties and hopes holding most of it together, although the fan does run freely. Doesn't move much air though, I don't think the ducting is at all tight back there.

When the A/C did work, I would get a nice cold temp back there. Curiously enough, the temps coming out of my front vents would drop by 5-8 degrees when I turned the rear unit on.

YakkoWarner said:

My rear bracket is all out of sorts. The plastic that everything screws to has gotten so brittle that its just flaking apart. Right now theres just a lot of zip-ties and hopes holding most of it together, although the fan does run freely. Doesn't move much air though, I don't think the ducting is at all tight back there.

When the A/C did work, I would get a nice cold temp back there. Curiously enough, the temps coming out of my front vents would drop by 5-8 degrees when I turned the rear unit on.

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The front system does seem to be boosted when the rear is on in mine also, and I usually at least use the rear fan on LOW when the front is on even if nobody is sitting in the back.

There isn't a lot of ductwork in the back. It is just the blower fan and an air deflector. If your deflector is missing or somehow not in the appropriate spot, that'd be a likely cause of the lack of air. On HIGH, I can feel the air coming from the back when I am in the driver seat.

Subscribing to this thread, as I am in a similar boat. AC system (with rear ac) was dead upon purchase. Found a massive leak at the front evaporator, right at the top of the side tank. I have no idea of the condition of the rest of the system, but the orifice tube was clean, which gives me hope. I would like to get rid of the bulky front evaporator setup to make room for future changes in the engine compartment, but that stock front evaporator is HUGE, and I am not sure how it compares to the Vintage Air system as far as effectiveness. Thinking of soldering shut the leads to the dead front evaporator to test the rest of the system first.

There is so much anecdotal information out there on what works and what doesn't, makes it difficult to determine. A/C systems are often not evacuated/charged correctly, even by many "pros".

Has anyone here used old air? I like the look of their complete kit for heater only cab

I can't really tell which compressor I need. If you go to RockAuto https://www.rockauto.com/en/catalog...5,heat+&+air+conditioning,a/c+compressor,6628 it lists several as a fit and look similar (although some can be discounted because the pulleys are not V-belt). And early on in this thread someone posted an eBay link for a compressor with the part number on the sticker on my actual compressor, but it looks nothing like what's on the truck and has the wrong pulley.

What are the differences btw the DA6, HR6, H6, HD6?

Doesn't seem like there should be this many options for a drop in replacement? Or am I missing something simple here?

Thanks

Well, here’s what I ordered. I also ordered (from Amazon) uv dye and a bottle you pressurize full of the flush to force it through the lines. I’m just keeping the lines in the engine bay, lines to the rear, and the rear evaporator/coils. Hopefully I can flush it well enough.

Can anyone confirm PAG 150 is the correct weight oil for that compressor? I saw differing info online, but most seemed to say 150.

I bought what I thought was the better quality options when multiple choices were available.

Pics of the compressor online all show a flying lead with two male spade connectors, vs the two exposed male spades right on my existing compressor. Guess I’ll make some jumpers if I need to.

Making some progress. Have condenser and front evaporator out and all the rear AC stuff pulled down (that wasn’t fun). Whoever said the wheel was just rubbing was correct. Looks like fa wheels aren’t on the shafts the same amount and the motor wasn’t centered either. Also, the plastic housing is all kind of cracked and one of the motor mount tabs broken off. So I’m going to clean and epoxy everything up, blow and flush out rear evaporator really well, and blow flush the lines back to the engine bay since those ends are open now.

On my 1987 suburban I was able to unbolt the cooling fan shroud and and upper radiator cover/plate and tip the radiator back enough to get the condenser out. Also, the part number I ordered appears to be a 100% drop in regarding size, mounting locations, tube fittings. Will know for sure once I flush the lines and try to put it in.

make sure the rear expansion valve isn't clogged up before you reassemble the rear system. it should be open at room temp and totally closed at freezing temps.

gmbellew said:

make sure the rear expansion valve isn't clogged up before you reassemble the rear system. it should be open at room temp and totally closed at freezing temps.

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Thanks. I bought a new one, so plan on replacing it.

Any thoughts on how to repair this heater box? Was held on with two short lag bolts at the bottom from inside the truck.
And the plastic tab that holds the spring/cable is broken off.

Anyone epoxy repaired, or maybe there are replacement tabs/reinforcements you can buy?