Porsche Enthusiasts Club Forum

Folks - Hope you can help me out here - I have a 1991 (Aug) 944 turbo that I was undertaking a brake rebuild on. I had the calipers refurbed and ordered new brake pads and shims . From the options sticker I do not appear to have M030 suspension.

I have a very odd problem As far as I can tell the correct brake shims are the plate type with 33mm and 25m discs with this part number 95135108904 - these shims do not fit the calipers. I called the OPC parts dept who gave me a different part number 95135108903 saying there was a change over in the caliper around that time ( which I cant corroborate)

So as far as I can tell I either have the wrong size shims or possibly the refurb company has sent me the wrong calipers back. The refurb company is denying all knowledge of sending back the wrong calipers. The calipers fit the disc Ok bit I don't know if the "larger" brakes have the same external dimensions and larger pistons or the are larger altogether


My question is how do I confirm what should be the right size caliper pistons for a 1991 Turbo so I can go back to the refurb company and demand that they fix the problem or find the right size shims - I could just order these but want to check tha I haven't been diddled out of smaller calipers.

To add insult to injury one of the calipers looks like it has been dropped on the cross over pipe which is bent and needs to be replaced

Are you able to post some pics of the returned calipers?

Photos as requested

Not sure if it is just the way you're showing the picture but the piston diameter is the outside diameter of the piston.
My parts list show all Turbos having 36/40mm pistons with M030 being 36/44mm

M030 calipers are radial mounted. A quick look at the caliper will tell the difference between the m030 and smaller calipers. Can you post a pic of the mounting points? Quicker than measuring anything...

I think Jim has solved the problem

I assumed that the cylinder protrusions from the anti vibration shims went inside the aperture of the piston

I take it I need to push the pistons back and the cylinders from the anti vibration shims sit inside the piston sleeve, with the pistons pushing the end of the shims?

Correct. And stick the other side of the shim to the back of the pad! As long as the shims pop into the pistons then you're sorted!!

Stuart

Not how I see it ......the shims fit inside the piston

That was my original thought. I assumed the shims cylindrical protrusions went inside the pistons.

I,m no expert but yes the shims go inside the pistons......

Pet lists 2 shims for the Turbo one is 6mm small in diameter I guess you have the pre 90 version

Looks like you need the 19/27 mm version

I'm sure someone will know for sure

How do I get access to PET?

Ok thanks for that I looked through the PET - It sees that kongsodoken and The OPC agree that the right part number 95135108903 shows different sizes of 19.7mm and 27.3mm, I have include a screen shot of the PET section in the pic. I will check the production date of my car as although it was registered in Aug 1991 it may have been produced earlier as it looks like there was a changeover to slightly larger pistons in 1990. - I will check it out and post an update to close the thread

On the 3rd pic I posted the number 89 is stamped inside the caliper - I wonder if this is the year of manufacture of the component

DC

That's what I said!! Said stupid cylinders screwed onto backing plate should disappear snuggly into the pistons and the backing plate should then be fixed to the back of the brake pad!

Stuart

Hey scam75 - I agree with you that was why I made the post as I thought the puck things should insert into the pistons and clearly the shims I had been given were not right