jpapanas

My inner rear brake pads were stuck in their calipers because of corrosion under the spring plates. The corrosion pushes the spring plates up causing the pads to get stuck. I had to take the calipers off to remove the inner brake pads.

To clean up the corrosion under the spring plates I needed to remove the screws holding the spring plates to the calipers. I attempted to remove the screws with a 4mm hex bit - got one off, but stripped the next one I tried. I'll probably have to drill this one out. Another thread on this topic suggested to weld a nut to these screws - but I don't have a welder...

Anyways, according to PET, it doesn't seem that you can order these screws separately - only in a repair kit that includes the spring plates - 993.352.959.01 - probably alot of $'s. Does anyone know another source for just the screws?

Regards,
Jim

jpapanas

Here's a pic of the stainless steel "button head" screws that I'm looking for:




Regards,
Jim

jpapanas

Found a source: http://www.brafasco.com

These screws are M6x1 thread, 10mm long with a button head and Allen keyed in 18-8 stainless steel - and a bitch to get out of the calipers without stripping them!

Regards,
Jim

Rally Guy

I'm in the same boat - rear pads on my S2 don't even MOVE! Any tips for getting the spring plates out?

For the fronts - as a hold-over till I rebuild the calipers all around - I filed the brake pads on the sides and used a dremel wire brush on the spring pads to clean them up so as to get enough movment to get the brakes working again.

These cars actually stop when the brakes work. I can barly imagine what they'll be like when freshly rebuilt!

Any tips on removing spring plates would be appreciated.

RK

jpapanas

I found this while searching - step 2. suggests to heat the head of the screw: caliper re-conditioning

I think the best way to get these screws out would be to weld a nut to the head as another thread suggested, but if you don't have a welder...

I still havn't removed all the screws. I'm worried about stripping them and making matters worse. My screws have brake dust and corrosion baked onto them making it difficult to get the 4mm Allen bit in. You have to scrape this out without deforming the shape of the Allen head.

Because of the awkward angle and the limited space to work in, it's difficult to put enough pressure on the 4mm Allen bit to keep it straight while turning the bit with a 1/4" box end wrench - there's no room for a 3/8" drive ratchet.

For the screw that I stripped, drilling the head off may not be a good idea because there may not be enough of the screw left exposed to grab with a vice grip and turn out. Forget about using a screw extractor - there's not enough room to get a straight shot at it.

I may end up taking my calipers to my mechanic...

Regards,
Jim

pikey7

If the screws are the same as in my front calipers, then THEY'RE NOT HEX BOLTS! They are T27 Torx head bolts, which is why you're stripping them!

To extract already stripped ones, use a small hacksaw blade to cut a slot in the head, and carefully use a stubby flatblade screwdriver to get them out. Ask me how I know...........

jpapanas

On the rear calipers on my 87 951, the screws are definitely 4mm hex(or Allen) heads. I tried a T27 Torx bit, but it is much larger and doesn't even come close to fitting. The PROSPEED page also confirms in step 2. "you will need a 4 mm allen wrench/socket" - see caliper rebuilding

I think that's a good idea - I hope I can get enough torque with the screwdriver...

Regards,
Jim

Stan944

Just a comment on an alternative way of removing stripped bolts:
Drill a deeper hole, and use a standard bolt extractor. This technique should work well on torx and hex bolts, as the hole is already there, and the drill wont slip off center.
The catch - if you break the extractor, you are in deep trouble!
Stan

jpapanas

In this case, you don't have a straight shot at the screw head because it's in between the caliper halves - you can only drill at an angle.

Here's a couple of caliper pictures from Perry's web site showing the awkward location of these screws. There are 4 screws per caliper, 2 for each spring plate:

caliper pic 1
caliper pic 2

Regards,
Jim