Since I need to replace my power steering belt, and since I have new belts for everything, I thought it would make sense to just replace all of them...God only knows how old they are. Plus, it's the prefect time to take the belt off the alternator and test if it really is the source of the clacking/clicking sound I get most all of the time (I'm about 99% sure it is). Now, my AC compressor has had no belt since I first got the car, so I thought I'd put one on and see what happens, but looking closer, I see this:





Check out the tensioning bracket assembly. Missing a few bits! What about the mounting tabs you can see here...should something be attached?

In an old thread, I found this diagram...are the missing tension bolt parts Porsche-specific, or can I get them at a hardware store? (Parts 6, 8, 10, 11). I'm also very curious about what appears to be mounting tabs on the bottom of the compressor that have threaded holes with nothing there. Should there be? Or are they unused in our application?

Here's the diagram:




Thanks in advance...

 

The threaded fasteners and washers can be sourced from any hardware store that carries metric fasteners of the correct diameter and thread pitch. Looks like all you need are items 6,8, and 10. The threads in the hole through the mounting tab may be bad which led to Item #8 coming loose. You can either drill and tap to the next largest bolt size or drill out to allow a longer M10 bolt (Item #8) to go all the way through the mounting tab and secure it with a self-locking nut on the back. If you go the "drill and tap the next size larger" route you may need to also drill the hole through the eye bolt (Item #9) to allow the larger bolt to pass through.

The other mounting tabs are unused.

Mike

 

Thanks for the info. I don't suppose you know the size of the missing items? Before I go drilling and tapping I'd prefer to try the stock size, especially since I don't really have any reason to believe the compressor is working..

 

#8 is listed as an M10x33 bolt
#6 is listed as a A 10,5 washer
#11 is listed as an M 8 "hexagon nut"
#10 is listed as "washer" but we know #8 passes through it and it's an M10 bolt.

 

Brilliant, thank you!

 

I'd also recommend planning to rebuild the compressor if you're going to hook it up again. If it's been dormant long the seals will have dried up and it won't hold pressure. There are a few very good write ups on rebuilding that compressor here (I think I either wrote one or contributed to it last year). I just finished re-building mine last spring, there's only one special tool involved and you can get a complete kit for it from Century Air (I think?). I'll dig through my records if you're interested.

 

Found the specials tool reference at:

https://rennlist.com/forums/928-foru...l#post11553741

There's also a great YouTube video on re-building this compressor. Still looking....

PS: You DO want to rebuild rather than replace the compressor. The rebuild kit is about $30. A rebuilt compressor is about $500.

 

OK, here it is. John Speake gave me the critical lead, you can find the whole thing here:

https://rennlist.com/forums/928-foru...ggestions.html

With the right (special) tool, the entire thing is a cinch. Takes a couple of hours, probably the highest return on investment you're likely to get from this list...

Good Luck!

 

I agree with "pfc. Parts". I wouldn't bother throwing the belt on, unless it has been gone through. Especially, if you don't know how long it has been since it worked properly.

Odds are...you will put the belt back on and have bearing noise. Especially, if the compressor has hung there, unused and without Freon, for any length of time. The *itch of it is...the compressor belt is the located closest to the engine and is captive by the bracket that holds it and the air-pump. So, if it does make noise...you have to remove all of the belts and those brackets, again, to remove its belt.

How do I know all of this? I have an 84 and just completed the TB and WP and threw a belt on the compressor because it was missing (just bought the car, so wasn't sure of its status) and it hollows like a son of a gun. So, off come all of the other belts to get to its belt, and back on go all of the other belts. The kit that "pfc. Parts" mentions sounds very interesting...note to self...add to list of interesting projects to-do-list.

I'd replace the bolts that hold it secure to the engine...but leave the belt off for now. That is...unless you have had the air conditioning working lately and you know that the system is charged properly.

Brian.

 

The hardware store probably doesn't carry #10. It is not a washer but rather a bushing and it is about 5 or 6 mm thick. Of course you can always stack a couple of #6 washers together for the same result, unless the purist in you wants the original part.

 

Wow, great info guys....I suspect, now that I think about it, that the reason there is no belt may well be because the bearings are shot and it was making a racket. At any rate, I'm pretty sure it's been several years of sitting around not working, and undoubtedly will need that rebuild. I had no idea it was something that was doable and cost-effective, vs buying a new one, so this is a pretty exciting update

 

For the purists, I've attached the complete PET page for the 86 assembly. The part number for #10 is shown as 928 101 303 00 if you want to order the original Porsche part. Leon's correct IIRC, that part is thicker than a washer and has a raised rim on one side I think. My guess is he's also right that a couple of stacked washers would do just fine too.

Regards,