MAGK944

Working on a friends S2 brakes yesterday and noticed he had some metal plates fitted between the back of the pads and the pistons. They looked stock, but I have never seen them before on any other 944.

What is their purpose? Are they supposed to be fitted to the turbo brakes also, same caliper so am I missing something?

Checking PET/manual to see what they are all about, but can anyone elaborate on their purpose.

vette951s

They are Porsche anti-squeal pads.

John

Potomac-Greg

I had them on my old Mercedes and someone told me they were titanium plates that provided heat insulation.

http://www.zeckhausen.com/StopTech/c...s.htm#Titanium

Oddjob

Well the porsche ones are not titanium. They are a thin rubber coated sheet metal with screw-on plugs that insert into the piston faces. The have an adhesive back that sticks to the brake pad. All done to reduce high frequency vibration (squeal) in the brembo 4-pot fixed calipers. Two styles for the early and late design piston/seals - early were a 1 piece plate (two per caliper) about the size of the pad, the later dampers were round and required 1 per piston, so 4 per caliper.

They are shown in PET in the brake illustrations.


Pretty close to worthless in my opinion. And because they are stuck to the backs of the pads, they get chewed up and often destroyed when changing pads. Very common that they are removed and never replaced, so not many of these 20 year old cars still have them in.

MAGK944

Good to know that I haven't been driving around in these things for years with a critical brake part missing. I found them in PET and yes they were stuck to the brake pads. I thought at first it was some sort of fancy pad design and that it was part of the pad.

Good info, thanks.

Luis de Prat

Unless you don't mind brake squeal or clunking pads when they begin to wear. I realize this doesn't matter much in track applications, but in a street driven car quiet brakes are a plus IMHO.

The 944S2 brakes take 16 of these shims in 4 sizes. This is for standard turbo brakes. The M030 brakes use the pucks described by Oddjob for the fronts and the shims for the rears.

MAGK944

Good point and I am sure they were designed for that purpose. As the pad wears these would hold the piston and pad together as an item. But I have never suffered from clunky pads or brake squeal, so I don't think these help much in that respect. I have always just coated the backs of the pads with copper grease and have never had any issues.

The worn pads I changed on the S2 must have unglued themselves from the shims some time ago, the pads pulled right out leaving the shims behind. I don't think the adhesive is that strong and certainly not up to doing the job.