Tom. M

I'm in the midst of re-doing the A/C in my GT and have a question:

I've got two compressors at the shop. Both turn freely and make that "pumping" sound when turned. I've cleaned them both up and am trying to figure out which one to use.

For the moment I'm planning on staying with R12 although I'll be putting in new o-rings (R134 friendly ones) in all areas (exp. valve, drier, condenser, etc). I will also be running a new parallel flow condenser in case I need to switch to 134 at some point.

"Compressor 1" I believe came from my 82 track car and appears to have been "gone through". It has green o-rings and is stamped CBF2 on the back and has a 2001 APG tag...I'm assuming it's R134 (orings) and likely 134 friendly oil...It was stored at the shop open as shown in the first two pics.

"Compressor 2" came from an 84 and has the old black o-rings and was stored with the attached hoses and pretty much sealed. I would gather that this one would have mineral oil in it. It's pictured in the 3rd pic below (the one with hoses still attached).

So...what does rennlist suggest?...compressor 1 or compressor 2?

Tom. M

Look what came today . Got this parallel flow condenser from that place linked back in another A/C thread (under $200 delivered). Just a couple more pieces on their way from 928 Intl tomorrow and I'll have everything to put my A/C back in the GT.

I've decided to go with the APG compressor since it likely has been rebuilt with R134 seals..I've got new seals/exp valve/drier that I'll put in along with a solvent flush of the evaporator and new barrier lines (rebuilt locally with barrier hose). Hope too to get the radioshack relay added to the a/c head unit. I also found the blue nylog locally so with some luck I'll have it all back in the car this weekend...and will then go to a local auto air specialist to vacuum down and recharge the system with R12....

Ed Scherer

Have fun getting the old condenser out and the new one in. IIRC, it's a pain to get to the fasteners for those tabs on the bottom.

Unless I can find a local shop I can trust to get my A/C going again, I'm going to be doing a bunch of A/C work sometime over the next few days... at least before the OCIC. Can't imagine doing the trip to/from Wichita in my black/black car without A/C. I really dislike working on the A/C system; it's been a couple of years since I messed with it last time, and I still have bad memories.

Tom. M

The old condenser has been out for years...and yea..pain to get those lower nuts/bolts. According to the other thread, this condenser is a direct fit but slightly smaller in width (all bolt holes line up though). Keeping my fingers crossed it goes smoothly

dprantl

Direct fit. I only had to very slightly bend the upper fitting to line up better with the high-side pipe coming up from the compressor. And it's easier to install if you don't have the external oil cooler under the radiator.

Dan
'91 928GT S/C 475hp/460lb.ft

Tom. M

Well...I just got my *** handed to me by one small 5mm allen bolt. It was in the expansion valve so tight that even with leverage (closed end wrench) it started to strip..

Any tips/tricks to getting that 5mm out of there... I just can't seem to see a way to get anything in there at the moment, and I won't be able to get the A/C back in if I can 't flush the system with the existing exp. valve in there...and that means one hot trip to the OCIC....

Lizard928

Put the Allen key in, the apply heat (small butane or propane torch) once hot try to undue.

Or you can get a right angle drill with short bit and attemp to drill it out....

Tom. M

Went to harbor freight and grabbed a butane torch and some new allen wrenches. Hit it with the heat and still no go...I think it's pretty much stripped on the inside now... Absolutely no room for a drill....I guess I'll have to get a dremel with a small cutoff disk to carve up the head of the bolt.

I also pulled the freeze switch (which was bypassed by the PO) and tested it. It works as intended so I am guessing it was bypassed to get the A/C cooler.. Can this alone cause problems with the compressor fragging?....

dprantl

Bypassing the freeze switch should not hurt the compressor, only that it will just run longer.

I had an expansion valve where one of the allen bolts stripped. It took a couple of painful hours with a dremel to get it out.

Dan
'91 928GT S/C 475hp/460lb.ft

Tom. M

Well, finally after probably 4 or 5 hours of futzing around, I was able to get the exp. valve out of there. Started with some heat from a butane torch. Upgraded to a a dremel cutoff bit... broke about 20 of them but managed to get the bolt head nice and chewed up. Next got a big drill bit and started chipping away at it. I nicked both lines (hopefully none were cut through)...but got it out of there.. only to find that someone had been in there before (green o-rings). Oh well. At least the smaller 4mm allen bolts came out OK.

Here's a pic of the damage..... Also have the head unit out and ready for a new relay. With the luck I had on the exp. valve......I think I might just get a friend to do this LOL. After that, a flush of the evap, lines and then put it all back together with a final trip to the local Auto Air place for some R12.. keeping fingers crossed it all goes in OK....About a week to go before the big road trip..

Ed Scherer

Another one for the trophy case!

Good luck on the rest of the job. Wouldn't want to make that trip without A/C.

See you in Wichita.

Tom. M

Desoldered the old relay off the board. It went just like Dwayne described. When I got it off, the old relay felt like it has something loose inside. Is that normal? Anyway, next step is to solder the new wires. I ended up getting solid core 18 gauge wire (Dwayne suggests stranded). Is there any problem with using solid vs. stranded for the circuit board/relay?

TIA

Tom. M

And a pic of the old relay.

atb

Hey Tom,
Way to hang in there. Should have some free nights this week if you're working out at the shop to get things buttoned up. Any other projects other than the AC to get the GT OCIC ready?

dr bob

Solid wire will be OK so long as all the pieces are securely in place.

On that expansion valve, next time try dry ice on the expansion valve body. It's aluminum, so heating it means the aluminum block expands faster than the bolts passing through the block itself. Freeze the block with dry ice and the bolt tension drops. Hopefully enough to get the bolts out. And... the sealing is done with the o-rings, so absolutely no advantage to overtightening them on installation. The tube ends hold the sealing faces square, so no benefit at all to overtightening the bolts beyond maybe 30-40 inch/lbs.