Ed Scherer

I should be ready to charge my A/C system (note: has rear A/C) later today after replacing the compressor with a Griffith's "Kuehl" one, and replacing and flushing condenser, evaporators, and plumbing. As per instructions that came with the Griffith's kit, I've filled the compressor with just shy (I saved a tiny bit for lubing the O-rings) of 8 oz. of ester oil.

Will I need to add any more (ester; this system is staying R-12) oil? The instructions aren't clear on this and the WSM on pg. 87-90 has two radically different amounts based on two different OEM compressor types (280 ± 20 ml for 6E171 compressor and 120 ± 20 ml for 10PA20C). This makes it clear that the compressor is the single largest determining factor of how much oil to use and now, of course, I have a different compressor than what's listed in the WSM.

I dug through the archives here, Nichols tips, etc., and I don't believe I've found a definitive answer for this combination of components.

Bill Ball

Hi Ed:

This should help. It's from Service Bulletin 9208, December 22, 1992.

Ed Scherer

Thanks, Bill.

Guess I'll make another NAPA run and get another container of ester oil and add another 2 oz. The recommendations I've seen are to err on the side of caution and add a little too much rather than having too little.

I won't obsess over it.

But... I'm starting to obsess over the fact that I found a fair amount of oily grime around the lower left end (when facing the front of the car working on it) of the condenser, i.e., near the exit tube. Both on the fins and the tubing. Perhaps it was oil spray from a loose fitting or something. Too bad my system was totally discharged when I started or I could have put a sniffer on it. Hoping for the best; I don't want to have to do a last minute condenser replacement a day or two before the OCIC; I'm hoping to have it buttoned back up today so I can turn my attention to getting the car cleaned up.

Ed Scherer

Wait a second... that table gives 3.3 oz. for the evaporator. Note it says "evaporator," not "evaporators". And the total of 9.3 oz. = 3.7 oz. + 1.4 oz. + 3.3 oz. + 0.9 oz. Do I add another 3.3 oz. for the rear evaporator, i.e., shoot for 12.6 oz.? Or does the "evaporator" figure actually include both evaporators, so I just shoot for 9.3 oz.?

borland

WSM recommended fill is max: 160 + 20 cc = 180 cc = 6 oz

Those component guides assume leak losses in excess of what expected as residuals. So they add up to more than the total recommended fill amount. If you flushed every component and gravity drained the compressor, then you should fill with 6 oz max.

I would just use the same WSM recommended amounts for R12 and mineral oil (ester in your case) even though you are using a non-factory compressor. The Griffiths hose lengths and compressor volumes probably are different which affects the system volumes. If you can find the compressor's factory recommended oil fill oil capacity, you could reverse engineer the quantity, but the result shouldn't be much different. Just make sure your pressures are according to the WSM Pressure/Temperature charts in Volume 4.

You should replace all 5 hoses (with rear AC) with barrier hose before you refill the system. The one hose along the left side of the engine is problematic and difficult to remove; so I bought a crimper tool for that one and crimped a new barrier hose in place. The two rear ac hoses require reduced barrier hose and fitting sizes.

Does the Griffith's compressor allow the belly pan to be installed?

Bill Ball

That table I pictured has an error in the compressor amount.

I did not include the column for GTS 93 on. That is the 160, Borland mentions. That compressor takes far less oil than earlier types.

I don't know what type of compressor Griffith's uses, but it may require the 8 oz (240 cc) that is installed in it. I wouldn't take out 80 cc. unless Griffith's specified that the compressor fill is to be adjusted.

GregBBRD

Call Charlie and ask him...he'll know what the system needs with his compressor.

worf928

Problematic doesn't cover that hose.

What crimper tool did you buy?

Yes.

borland

Dave,

Due to the location and age, its a leaker. Besides barrier hose is far superior to what was installed by the factory for those R12 cars.

They no longer make the crimper that I bought and resold. It was an ATCO model something. Today, I'd buy and resell this Mastercool Hydra-Krimp crimper..

http://www.acsource.com/index.asp?Pa...ROD&ProdID=156

Slightly less with shipping on eBay.

worf928

And if it is a rear a/c car you cannot replace the line with the motor in AFAIK.

Holy sticker shock Batman!

Thanks for the link.

Rob Edwards

Dave-

It can be done, but I wouldn't ever do it again......

https://rennlist.com/forums/928-foru...ion-stuck.html

worf928

Ok. This is funny. You know why? Because it finally explains what I saw on one car where the LH harness was crushed between the high-side and low-side lines.

(That harness ended up with some severe problems, perhaps, in part, due to the mashing. I had to cut it out.)

So, Rob, would it take less time to pull the motor to R&R that line on a rear-A/C car (or even a non-rear A/C car) than to do what you did in that thread? (Not a rhetorical question.)

fraggle

**** I just put my motor back in.

Looks like no AC for me for awhile, I need to refurb my entire system as it leaks like crazy.

Rob Edwards

Dave-

Knowing what I know now about engine pulls and R&R'ing that line, I think it's still probably easier to do it with the engine in. However, to the degree that the line is going to get bent, you really do run the risk of crimping and/or cracking the hardline portion of the A/C line. Honestly, I think I prefer Borland's door #3- beg borrow steal or buy a Hydra-Krimp and R&R it in situ. You should be able to disconnect all 3 ends and maneuver the hose up enough to crimp new fittings. Or maybe you don't have to disconnect the line, not sure how much room a Hydra-Krimp needs.

There's a reason the hydra-krimp is expensive. It's worth it....

dprantl

Guys, you don't need the hydraulic portion of the Hydra-Krimp. You can get the exact same crimper without the hydraulic cylinder with dies for under $200. Instead of the cylinder, there is a large bolt to crank down on. I have one and have used it successfully for years.

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