Yet another Denso compressor reseal question

[Bukowski]

I found links to reseal tutorials for Denso compressors for 911's on Pelican Parts and Rennlist - how much of a guide will that be for the compressor in a 944?

[mhariush]

Are they different? I would think they used the same compressor for the same years?

[mattdavis11]

It's the same procedure. The early 944 has a 6E171 and later a 10P15E compressor. Order the right parts and you're good to go.

[Bukowski]

And is the car expected to operate normally if the compressor + belt is removed?

[dgcantrell]

You have to get the AC Delete bracket and move the Alternator down to the AC slot. Shorter belt too.

I'm going to need to probably rebuild my compressors on all of mine. Looks like I'll be needing some special tools...

[djnolan]

If you are rebuilding because the O-rings are leaking it is a piece of cake. If however you are replacing the shaft seal you might consider a rebuilt compressor.

[dgcantrell]

I'm pretty sure it's the shaft seal and everything else. It's not been charged in 15+ years.

[djnolan]

I have two running systems both on original shaft seals and one is on original O-rings too. The 85.5 needed the compressor case large O-ring seals replaced. The 87 is lower mileage and is completely original seals and doesn't leak at all. With A/C alot of times it is the little things that make the difference, gently tightening up joints or shrader valves.

[Bukowski]

Mine is leaking out the back. How would I know if it's a shaft seal?

What should I plan on, 3 hours straight?

[mattdavis11]

Sealing the case is actually more involved than changing the shaft seal. The only special tools you need are a jaw puller (if the pulley doesn't want to come off) snap ring pliers and a 5 mm allen socket or wrench.

One mistake I see people make when resealing is that they pay no attention to the shaft where the old seal rode. The shaft needs to be polished to the point that it is smooth, void of any groove or burs that the old seal left.

I also prefer to use a lip style shaft seal over carbon. If you use a lip style, you will not need a seal driver.

[mattdavis11]

Originally Posted by Bukowski

Mine is leaking out the back. How would I know if it's a shaft seal?

What should I plan on, 3 hours straight?

Leaking at the back would likely be the case seal at the rear head, or possibly manifold plate gasket. Shaft seal leaks leave the entire compressor coated in a dirty black oily residue. Small shaft seal leaks are very hard to detect with the naked eye as the clutch hides the leak from view.

Which compressor do you have? Normally I can reseal in under an hour after it is off the car, but I take a lot of breaks and take my time cleaning things.

[mattdavis11]

Almost forgot, an impact gun is most helpful for the clutch, case and manifold bolts. Doesn't require much torque, but a little jolt helps a lot, especially with the clutch bolt.

[djnolan]

Oh that is right. To change the large orings, the through bolts are behind the clutch pulley and removing that part is a little difficult and requires patience and or special tools. Snap ring pliers, and a puller or gently prying off the clutch plate with a pair of screwdrivers although a puller is preferred. Whatever you do don't bend the shaft when you pull off the clutch plate. Tightening the through bolts (allen head) is also a little tough unless you have a large vice to hold the compressor in.

However after 5 years or more mine is still holding freon.

[Bukowski]

"Shaft seal leaks leave the entire compressor coated in a dirty black oily residue. " -mattdavis11

DING DING DING

I was wondering where that came from....

Couldn't it be from above though? Air oil separator?..,.

I saw green bubbling out the back, but nowhere else visible by poking my head under real fast.

[mattdavis11]

You do have a case seal leak at the rear head, but most likely also have a shaft seal leak. It's not that hard to fix either. Get the right seals, and get'r done.