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

Hi all, I bought this clean 1987 R20 454 Suburban a couple months ago. The AC didn’t work, and when I hooked my gauges up only had about 10 psig on the low side. It had r134 fittings already, but I went ahead and replaced the schrader cores and replaced the orifice tube and o-ring. Pulled a vacuum for 45 mins and it only dropped a little after 10 mins with pump off, so thought I was ok to charge it. Nope, high and low side stayed lower than temp/pressure table readings should be, vent temps only in the 70’s and the compressor compressor started weeping uv dye oil from the ends/body joint over the next few days. The orifice tube looked kind of black deathy also.

Also, defroster fogs the windshield and vents blow foggy air and there is the smell of coolant, so I’m guessing heater core is DOA.

So, what to do? I don’t mind paying once for the vintage air kit and replacing everything at once, higher cfm blower, etc., but I don’t want to drop that coin and be disappointed by the cooling in a suburban with lots of ppl in it in Virginia summer.

Would I be better off replacing the compressor with a big sanden? What model will fit my brackets? Do I need to get new evaporator and condenser sized for r134 also? I’ve seen conflicting reports.

I’m at the point in life that I’d rather spend the money and do it right all at once and have functional cooling and defrost now than fuss around with trying to get the ac to work right by just replacing one component at a time and crossing my fingers.

I’ll do everything myself, not taking the truck somewhere.

Thanks for your thoughts,

Mike

I'd replace what you have. Way simpler to find parts down the road.

BTW - that's only the second of that style compressor I have seen - both here on this site.

I am used to A6s and R4s . I forget the terminology for that one.

RA6, maybe ?

*Edit*

HD6, I believe. If wrong someone will correct me.

Goldie Driver said:

I'd replace what you have. Way simpler to find parts down the road.

BTW - that's only the second of that style compressor I have seen - both here on this site.

I am used to A6s and R4s . I forget the terminology for that one.

RA6, maybe ?

*Edit*

HD6, I believe. If wrong someone will correct me.

Click to expand...

I was trying to find that compressor and from pics I found it was listed on a straight-6 engines truck I think. I couldn’t cross reference it to the 454, so wonder if it’s been swapped. The lines look like they may not be original to the truck?

I’m not bothered with originality as long as there’s cold air.

Anyone know how much that HD6 weighs, compared to the old boat anchor A6?

The brackets for my original A6 were thick iron, It was bolted down in two places to the intake, and had at least two supports that used the exhaust manifold bolts. One of the exhaust brackets also supported the PS reservoir, so it was tied in. My point - it was so heavy that it required a more robust mount than what I think I see in the pictures above. However, that HD6 bracket also looks pretty solid.

I’m with @Goldie Driver , repair the stock A/C system.

Sure it’s broken now however it is 37 years old, I doubt the vintage air systems would hold up to the abuse the GM system has seen.

Don’t get me wrong, I do like the vintage air stuff and that’s what I put in my build but I didn’t start with a factory air cab.

I put a vintage air R134 a/c system in my mid 80's CUCV blazer many years ago. It would do ok for the front but not for the rear seating, and I did a pretty good job of insulating, sound deadening and window tinting. Maybe their system has improved.

stock rebuild for the win

75gmck25 said:

Anyone know how much that HD6 weighs, compared to the old boat anchor A6?

The brackets for my original A6 were thick iron, It was bolted down in two places to the intake, and had at least two supports that used the exhaust manifold bolts. One of the exhaust brackets also supported the PS reservoir, so it was tied in. My point - it was so heavy that it required a more robust mount than what I think I see in the pictures above. However, that HD6 bracket also looks pretty solid.

Click to expand...

5-10 pounds

Id say



ID say go for a HD6, but there are many options it looks like the overall trend was improvements in designs but the same profile, so as long as you have the right switches and clutches/pulleys it will work, but that means finding out if THAT is an HD6 on it or if its another. its not an OEM one.

This is the sticker on it. I didn’t have much luck getting anything from it online.

AuroraGirl said:

5-10 pounds

Id say

You must be registered for see images attach

ID say go for a HD6, but there are many options it looks like the overall trend was improvements in designs but the same profile, so as long as you have the right switches and clutches/pulleys it will work, but that means finding out if THAT is an HD6 on it or if its another. its not an OEM one.

Click to expand...

Thanks for those pics, helpful.

beady said:

This is the sticker on it. I didn’t have much luck getting anything from it online.

Click to expand...

I just did a quick search and I am pulling up P/N 2370191 as a 4 Seasons.

Vintage Air does make a quality product and from my limited personal experience their customer service is decent. I recently did some electrical troubleshooting on a couple cars with Vintage Air and their schematics were well drawn, their product is good quality.

However, starting with your factory air gives you an advantage IMO. I agree with @Goldie Driver on this one. Easier to find replacement parts, a more integrated system.

What I would recommend is to get the right compressor. It sounds like you are willing and able to spend the money to do it right, you don't want to go back with the cheapest thing on eBay.

My experience with Sanden is very limited but a little more research can help you determine if they build a better replacement. What you have needs to go.

LS swap. It won't help the ac problem but it will make you not care about it any more.

Another vote for stock. It looks like you already have some replaced components (i.e. hoses look newer, as does the filter/drier canister). Obviously you have found issues on the compressor, I'd check the lines going to the rear unit as well, and just generally do an assessment on what you have, what condition it is in, and go from there. If you need a new condenser coil, a parallel flow unit will give better performance than a tube/fin type that might be on there now, but may not be worth swapping just for fun-sies. If you really do have black death, then yeah, flush or replace everything you can. Remember the Filter/drier gets replaced no matter what. And if you replace major chunks of the system all at one time, make sure you pay attention to how much oil comes out (when possible) and how much goes in.

Hunter79764 said:

Another vote for stock. It looks like you already have some replaced components (i.e. hoses look newer, as does the filter/drier canister). Obviously you have found issues on the compressor, I'd check the lines going to the rear unit as well, and just generally do an assessment on what you have, what condition it is in, and go from there. If you need a new condenser coil, a parallel flow unit will give better performance than a tube/fin type that might be on there now, but may not be worth swapping just for fun-sies. If you really do have black death, then yeah, flush or replace everything you can. Remember the Filter/drier gets replaced no matter what. And if you replace major chunks of the system all at one time, make sure you pay attention to how much oil comes out (when possible) and how much goes in.

Click to expand...

Thanks. Yeah, I’m torn btwn spending $ to try to flush stuff vs. just replacing with parts that’ll have better heat transfer, etc. I do like the idea of clean, r134 sized heat exchangers, but if they are already large enough, and not much more than buying a bunch of cans of flush it makes sense to go new.

Here are some pics of the orifice tube I took out, what do you think? It could’ve been half-assed flushed before.