964 Rear Brake Pads (1993)

[Guest]

Went to change my rear brake pads, and, managed to removed clip and electrical warning connection.
Eventually prised open the two sets of calipers but was unable to removed the old pads.
I could wiggle them, but they were not coming out.

Can anyone who has done this before advise?

I also notice on the back of the exisiting pads there are two circular pieces which look like the back of a torch bulb. These pieces locate within each of the calipers.
The new pads I have do not have anything on the back of them, however, they are the same shape etc. The guy at German French and Swedish advices they are the correct ones and it is probable that the new pads do not have the circular piece on the rear because they are not genuine Porsche (they are of German manufacture though).

Jamie

 

[sawood12]

I'm looking to do this on my car this weekend (same or very similar calipers than yours I believe) so have been reading up on it and am interested to see what responses you get. From what i've gathered so far there is a backing plate that has two spring clips that clip into the caliper pistions. The back of the brake pad is then stuck to the plate using double sided sticky tape as a sort of anti-vibration measure. The manual suggests you use a thin, blunt, flat bladed spatula to prize the pad from the backing plate, being careful not to damage the backing plate in the process or it will need replacing. What i've not sussed out yet is do replacement pads come with replacement tape, if not where do I get some / do you need it at all?

Does this process sound familiar to those experienced in this?

Cheers.

 

[kevin]

These parts are the anti-rattle mushrooms/pads, your choice to reuse them, buy another set or leave them out alltogether. people do all sorts. Try Berlyn services see if Bert has any instock, he keeps most parts, and really should be your first port of call.....I've used Bert before and always had good service.

kevin.

 

[Laurence Gibbs]

Both other reply's are spot on they are the anti-rattle/squeal shims they are circular with a push fit into the brake pistons. My own personal advice would be either reuse or replace , don't leave them out or squealing could result.
if you reuse , I have used superglue to bond the shims on, last set I removed were still bonded on nicely using this but were still removable. Probably not ideal but it does seem to work. It may be that the residual old glue helps.

 

[Ian964]

I changed my pads last week, didn't bother with re-fitting the anti-squeal bits. I got the parts from Bert - his suggestion was just to use some double-sided tape if I wanted to reuse the old shims. New shims come with a layed of double sided tape on the pad side ayway.

The old rear pads did have them on, I used a 1 1/2" paint scraper to separate them from the pads before pulling the pad. Doesn't seem to be any noisier without them.

 

[Guest]

These items are the anti-squeal shims and come with an adhesive backing. I've tried fitting pads with and without them. I went back to having them fitted as I was experiencing a squeal when braking gently at low speeds. Fitting these shims/mushrooms eliminated the squeal. Porsche dealerships will never fit pads without the shims.

They can be removed with a paint scraper or a flat blade screw-driver.

Regards

Steve

 

[sawood12]

So what would be the consequence of fitting the anti-squeal plates but not bonding them to the back of the pad - or even applying a film of Copperslip inbetween to aid future replacement? Surely the hydraulic pressure pushing against he back of the pad is more than enough to stop any relative movement between the pad and the anti-squeal plate?

 

[kevin]

The mushrooms are there to prevent pads from touching and oscillating ever-so-slightly, the seals around the pistons retract a small amount after applying the brakes, the bonded mushroom will pull the pad from the face of the disk ever-so.....copper slip is unlikey to do this.
kevin

 

[Guest]

Ok thanks for ALL your replies.

I now understand what the shims do and how to remove and re-attach to my new pads.

How do I removed the old pads once the caliper has been fully opened.

I have changed pads on other cars, but this is my first Porsche.....I do not seem to be able to access them, only from above.
I need to get a manual (I know).

 

[Ian964]

Once you've got the clips and wires out the way, you will probably need to separate the shims from the pads in the caliper from above. Use the paint scraper or knife and slide it between them - can be a bit fiddly getting it started, but once you've got it under the edge of the shim it's easy. The pads should then just pull out from above - may need a pair of pliers or a pad puller. Then remove the shims - I broke a couple getting them out as they had to be levered out of the piston, so you need to be careful if you want to re-use them.

 

[sawood12]

There are a couple of 944 guys who run happily without the shims so the pistons are acting directly on the back of the pad and just apply a thin smear of cooperslip on the back of the pad. I'm going to give this approach a go first as it will make changing pads easier in future. You can always add the pads at a later stage if you need to.

 

[sawood12]

Just for info i've just received my EBC Red Stuff pads and the fitting instructions specifically says not to re-fit the OEM anti-squeal shims. There appears to be a shim of some sort already bonded to the back of the pad so maybe that is the anti squeal feature on this particular brand of pad.