Automotive Air Conditioning Information Forum

Looking for advice re: 1990 Grand Wagoneer A/C

Am a brand new forum member & a n00b to A/C; am working on a 1990 Grand Wagoneer that came with non-functional A/C. From what i can tell, the previous owner bought the rust-free body as a roller & the engine (AMC 360) separately & had the two mated. The engine came with TBI EFI & A/C compressor (Sanden SD709) installed. The compressor has R134A fittings, making it appear to have had a R134A conversion done; while the body has what appears to be the 1990 original condenser, drier, hoses, etc. (more on this later).

A couple of months ago, I had the Grand Wagoneer at the shop to replace the oil pan gasket, and while they were in there, i asked that they check out the A/C system & let me know what needed to be done to get it going. They said the system was empty; pulled vacuum on it & it held. So they asked if i'd like it charged & dyed to help find any future leaks? Excited, I told them to go ahead (not taking the Frankenstein nature of the vehicle into account & that it was highly likely that only the compressor had the R134A fittings installed...) - ugh...

Shop noted that the discharge temps weren't very cold; to drive it & give a yell. Off to the parts store for a vent thermo, like my dad had years ago, to see what we were working with.

Disappointment: 70 degree air. This was on a 95 degree day after having driven for 45 minutes.


A few days later, i noticed a slight leak (neon green) on the compressor faceplate, making me wonder whether a compressor rebuild may be in order, and began reading various forums, incuding this one, as to what should've been done as part of a R134A conversion, including swapping the drier - which made me wonder...?? Surely not... Yep - 1990 factory original... ugh. Looks like i have a 1/2-swapped system.

Am thinking about going back to the shop to have the R134A removed, to allow swapping parts, but not sure where to go from there to get dug out of this? At this point, i don't have a set of manifold gauges. Should i get a set & see what the pressures look like before proceeding any further?
- First, there's the compressor leak; Have seen ACKits.com sells seals & gaskets to rebuild; and YouTube videos and the Jeep TSM showing the process. I'd like to try a rebuild - anyone had success doing this on a Sanden SD709?
- Then, there's the drier that needs to be swapped
- Hoses? etc.?

Compressor we're working with - sticker is mostly unreadable:


Also, looking at parts:
- Gasket sets: I'm seeing 2 gasket sets, one for 4.5" & one for 4.7". Short of disassembly, how do i tell which one i need?
- Shaft Seals: I'm seeing 2 types of shaft seals; a one-piece & a two-piece. Again, short of disassembly, how do i tell which one i need?

Please be aware that the site owner, Tim, who operates ACkits.com, is very helpful, and it might be a good idea to call him if he doesn't see this post with your gaskets and seals questions.

It is not clear how mechanical you are.
If you anticipate doing much of anything yourself you would be advised to get a set of manifold gauges. If you have been following on this forum, you may have noticed that the ppl who buy the super cheapie stuff from Horrible Fright and Amazon usually get burned with the low quality.
Tim's prices are very competitive and he has good quality parts. I have purchased several items from him, including a Sanden 508 knock off which is actually Japanese made and very well made, the quality is so obvious just from the outside. You can get a nice manifold set from him that you will be happy with.

As far as your other questions, they are beyond my paygrade and we need to wait for others to respond

Thanks, thirdtbird, on the mechanical question: Am a computer guy by trade, with a penchant for old house resto - before the Jeep, my shop made sawdust, with car work including simple stuff: oil change, brakes, water pump, valve cover gaskets, etc. Anything more than that, went to the shop. With the Jeep, it’s been difficult to find a shop who’s willing to work on Frankenstein - so, let’s say I’m getting there - nearly everything I’ve done in the driveway, things like: leaf spring swap to stock, rockers/pushrods, radiator flush/belts/hoses, brakes all the way around, and a myriad of electrical troubleshooting/fixing of electrical gremlins, due to hacked wiring & TBI EFI performance issues. Am trying to do everything I can to avoid the shop, unless a lift is required. It’s been slow, but am learning a lot & willing to dive in.

Good.
I would also suggest reading as much of this forum as possible, it is a free tutorial.
I would actually start as far back as the current forum goes (there was a software switchover some time ago), and step thru the pages all the way to the present. If you want to learn, there is a core group of experts here, like on NO OTHER forum (and I am on several). These guys are MACS certified and some have MVAC field engineering experience/were employed in the industry and thus know stuff no one else knows.

I would rather not give names but you will quickly figure out the 3-4 people I am referring to

I have been doing MVAC and HVAC for 30 years and I thought I knew a lot. But yikes have I learned a bunch more from these guys

Short and simple.

R134a conversion needs.

Barrier hose.
R134a compatible drier.
Compressor with proper oil.
And most importantly, a Parallel flow-designed condenser.

As for compressor gaskets, they are available;e but why. A Sanden (import) is not that expensive, and since you'll need to redo so much. It makes sense to me to replace. Seen too many gasket repairs done with not so good results costing many recharges adding cost.

There ya go, the forum owner ran an AC shop in the past

tbirdtbird wrote: ↑Mon Sep 27, 2021 10:32 am There ya go, the forum owner ran an AC shop in the past

Yep, and I had AC service done there twice (I was local).

And have purchased at least four compressors, one evaporator, one vacuum pump, expansion valves, and plenty of miscellaneous stuff like driers from ACkits.com

Why four compressors? Two R4 for two GMC Yukons, two for my 1988 Mazda truck over the last 30 years. So far have not needed one for my 1998 and 2004 Frontiers.