924 turbo - caliper piston part# ?

[82 sportsc]

Guys Dont seem to be able to find part number for just the caliper piston ?
81 turbo…these are the single piston floating type
54mm dia & 53mm height…
Maybe same as 944 NA ?
Thanks
For assistance
Frank

[944 Ecology]

The part numbers for the calipers are different. The part numbers for the seal kits are different.

I would deduce that the pistons are different.

[82 sportsc]

Agree
they may be different….but think they might be same since just a piston …so
What is part # for either one ?
Thanks
Frank

[944 Ecology]

No part number listed, but there are indications that the 944 piston is 54 mm.

[82 sportsc]

Thanks…yes on size per my initial post , do you have these pistons ?
54mm dia 53mm height

Thanks
Frank

[944 Ecology]

Originally Posted by 82 sportsc

Thanks…yes on size per my initial post , do you have these pistons ?
54mm dia 53mm height

Thanks
Frank

No, no new parts.

check here:

https://tinyurl.com/3vr7rahn

[Monkey Wrench]

for that sort of price, Id just replace them. In my volvo 122 what I did was turn new ones from stainless, rather then the OE chrome. it has 3 pistons, I made enough for 2 cars while I was set up.
In theory they won't have the chrome flaking off issue. I questioned weather I should do that as they are important, but i had no issues. the shops that do hydraulic cylinder repairs can re chrome them if needed too.
the option in the above link is so cheap it's not worth the time. It's a solution if they are unobtainable.

[82 sportsc]

Monkey wrench…..
Agree
Have a call to them to confirm fitment, will see
Thanks
ft

[Monkey Wrench]

while you are in there , dont forget to give your rotors a spin to see if the wheel bearings feel nice or if they feel grumbly. I just went there with a 89 Volvo 740 and had to put it all back together temporarily because a ( outer) cone lost about 1 1/2 of it's rollers , completely pooched ! i couldn't even tell, the problem was they were squealing.

of course it was blocking all my other spare cars from leaving my drive as I was expecting a short pad swap not a different problem. ;-) I put some anti squeal stuff between the pads and the squeal strip. this stops the squeal but leaves them feeling a bit rubbery at least for a while.

I even had spare complete struts with brakes but the spares I had used a big nut with no cotter pin , instead of a castle nut and cotter pin like my car. I guess they evidently went to an interference type nut and it takes a high torque so I had trouble holding my spare volvo strut down AND turning the wrench with them out of the car. that became an exercise in frustration but I can go put them in a shop vice and try again. I learned it's a LOT easier to get that nut off with them in the car still. I could have swapped struts but then I probably need a wheel alignment too.

I ordered a new hub with bearings but it too was the newer style.. about 1990 so I might need to order the cone bearing instead. it can be ordered by the bearing number and is used in other cars as well so the actual bearing does not need to be OEM specific. Maybe they hub and nut will fit , or not , Ill see ..

another thing I'd check if it uses a floating arrangement if it uses only one piston , is that the two parts can slide but have no excessive play. I had a volvo 740 ( Bendix) one where the guide pin was ok but the bore in the caliper casting wore oval so much it made my brakes rattle over bumps, the rattle went away if I was braking. I'm not sure if that's a problem with Porsche calipers but Its probably worth checking out. most of the old Volvos I've worked on had 3 pistons and were Girling, No floating parts. I like those ones better. i think those slide pins should be lubed but I have no particular experience with Porsche brakes so check with the others or the manual. .

if you do repack the bearings I'd note down the bearing numbers while you have it apart. It's usually stamped on them.


i ordered seals, dust caps and hoses for my porsche 944 , It's on my to-do list too. I think Ill plan to take the time to wash all the bearing parts in solvent unless they are sealed bearings, and repack with fresh grease. any teeny bit of dirt or grit can cause a bad bearing and a subsequent "experience" I dont know if the brand and type is important, I'd use fresh wheel bearing grease. and not a tub that sat around the shop with the lid off. I'm sure there is a recommended type.

I think it's an easy mistake to pull off a rotor and replace it again, maybe only wiping out the grease with a clean cloth and putting fresh, thinking all is still clean and ok, but any tiny bit of grit in there will cause trouble.

the "volvo" hub I ordered is made in china, another cause of trouble may be using these cheap made in china bearings, Id go with NSK SKF or some other commonly known brand if you can afford that. I dont trust off brand made in china bearings farther than I can throw them. I see them failing in short order on machinery. I'm not an auto mechanic by trade, I'm a millwright. the Chinese ones sure are cheap to buy and the 740 is just an old workhorse so I sprung for 20 dollar cheapo rotors. they look OK , maybe cheap metal though. you get what you pay for I guess. the Porsche deserves better ! ;-)

so what I learned was that volvo changed from a castellated nut with a cotter pin to an interference nut with no cotter pin and that change was about 89 - 1990
I dont know if Porsche used anything but the castle nut and pin. I'm not sure if the bearing should have some preload, I dont usually go further than the last hole I can reach easily without actually tightening the nut any, but I'm sure there is a proper sequence and it may or may not want some preload.

[82 sportsc]

All great points….I always replaced all suspension components & brake with new or rebuild
Thanks for pointers
ft