A/C Compressor rebuild.

[Porsche 2]

How does one access or "open up" the article labeled "1988 Nippondenso A/C Compressor Rebuild" included in the Tech Info section? I am looking for the detail on how to remove the compressor shaft seal, having already removed the clutch and pulley sections from my 1987 A/C compressor. There is a slip ring retainer that is smaller and difficult to access, see photo. I will be attempting to source a set of slip ring pliers to help remove this slip ring. Once I remove this slip ring, is it then difficult to extract the seal?

[Nick Triesch]

Hi. I tried this from the article from our host. I failed. I did everything twice with two kits and after the unit was carefully put back together.....it leaked from all the o rings. Maybe the compressor was just too old. Check in the tech section. It will show you how to do it. Also you can get the slip ring pliers from harbor freight.

[Porsche 2]

Thanks for your quick response. I believe this model compressor allows the shaft seal to be replaced without disassembling the compressor itself (unlike later models). I am headed to HF to find a suitable pair of slip ring pliers. I hope the shaft seal can then be easily removed and replaced? But how do you open the tech article - I find the article title, but can't open it?

[rekstein1]

You Tube is your friend. Just did this check out the video Denso rebuild. Its done by the guys who are professional compressor rebuilders.

[rekstein1]

Forgot to mention did the HF thing to, the $10 pliers will be to thick you are going to need to grind them to fit into the c clamp

[kuehl]

Ideally you use 3 pairs of snap ring pliers; 2 are external and 1 internal; the size is determined by the hole size of the ring.
If the host, PP, does not sell them you can pick up sets at most brick and mortar auto parts stores or purchase them online.

[Porsche 2]

Thanks all for your help. Shaft seal assembly is out after picking up long thin nose pliers from FH. Clearly it needed to be replaced, but I see the large (outer) and small (inner) O-rings are the only items that appear "old" in the assembly?

[kuehl]

1) FYI, if you are just trying to replace 'just' the nose seal, you are cutting yourself off a the ankles. The benefits of opening up the entire unit are:
A) Inspection of pistons/bores and wobble plate for wear, as well as reed valve inspection and debris inspection. Does not make sense to put on a nose seal if the there are other issues.
B) The 3 case o-rings and 4 manifold o-rings can leak over time.

For the nose seal:
1) Nose seal assembly, metal bracket with spring and carbon, is inserted with the carbon side up when you are looking down into the nose. You will notice the metal bracket has 2 flats shaped in the hole where the comp shaft goes through, these align with the flats on the comp shaft. Try not to touch the carbon too much an insure there is not debris on it.
2) The large metal washer, or "race", has a shiny polished side, this faces the carbon (ditto on handling and debris on its surface). The thick o-ring that goes around the race... make sure you lube bore of the front comp nose assembly with plenty of refrigerant oil to insure it does not bind going down in the nose, and it does not get hung up on the groove cut in the ID of the nose for the retaining snap ring.
3) Where the old nose seals inner o-ring contacted the compressor shaft, there will be a 'witness mark', insure this surface is not corroded.

[Porsche 2]

Very helpful comments, thanks. Car is generally in excellent condition, having been on the south and north western coast all its life and kept in closed garages. I will replace the shaft seal assembly and the four manifold O-rings, but will take a chance on not splitting the compressor case!

[kuehl]

'Splitting" ,rather opening, the case is easy. Seriously, a shot in the foot if you don't replace all the o-rings (case o-rings). You get an ex-wife's cookie sheet. Open the unit over it and just remember the parts (reed plates) in the nose are alike the parts in the back and just keep them separate. When you split the center halfs just hold onto the shaft and keep the pistons in the front half; this way the pistons and bearings don't fall out.

The torque for the 5 long allen bolts that hold the case together is 18 ft lbs, same for the 4 allen bolts that hold the manifolds on.

Just go for it!

[Porsche 2]

You are very persuasive

[kuehl]

Some days

[T77911S]

kuehl,
is this really something that can be rebuilt at home and be reliable?
this just does not seem like it would be worth it based on the chances of it working.
(time+work for rebuild +time+work+refrid.=$$$)

[kuehl]

Well:

1) You are not 'rebuilding', you are inspecting and re-sealing.
2) Chances of success:
A) Tends to be better on compressors with less than 100K miles in 'general';
if the the compressor was used often there be more wear, if the compressor sat
on the car and the clutch was not engaging often you'd have less wear.
B) If you are handy, you have a torque wrench, a good set of eyes and you know when to leave the card table, you are the wiser.
3) There are some people whom like to explore and fix and others whom know where and what they'd prefer to spend their time on.
4) If the bores and pistons/pistons,wobble plate and its half bearings, reed valves and plates and shaft are good, the odds are in your favor.

Some clients we suggest to simply replace the compressor because you 'get that feeling', others want to take a shot at resealing it; tear down the compressor before you buy a seal kit!