987 Brembo brakes and anti vibration shims

[Chuckie66]

I recently replaced rear pads and discs with the Brembo brand from ECP, then at relatively great expense installed new shims as heard these would prevent break squeal. All great under moderate to heavy brakeing but noticed passenger side squealing under low braking, I think they call this the glazing effect. Anyhow, upon investigation I found the shims had detached from the brake and lost all stickines. Reluctant to buy more shims, what can you use to stick the shims to the pads? something that is heat resistant?

read also that you should use copper grease on the plug side of the shims so they don’t rust into the Caliper piston? I had one that seized in, partly why I bought new shims as were knackered by the time I pulled them out. Anyone put copper grease on to prevent this?

btw is there a guide anywhere which details the shim installation which calls out these issues?

 

[Motorhead]

Charles,

Were they genuine Porsche shims or OEM? I'm surprised they've become detatched - maybe there was some oil or contaminant on the pad backplate?

Can't help re the use of copper grease on the shim plugs, although I think they're usually fitted dry. Here's a good video clip FYI:

https://www.youtube.com/watch?v=vsLZFxO5c2M

Jeff

 

[Lancerlot]

Adhesive between shim and pad is not essential. There is adequate clamping between pad and piston to maintain shim alignment. You can give the surfaces of the shim a light greasing to aid fitment of the assembly if necessary.
I would use Optimol TA grease very lightly on the piston/shim surface to prevent seizure.

You should check the runout of the rotors with a dial gauge to identify any distortion/warping. Also deglaze the friction surfaces with a light abrasive. This should resolve any brake squeal problems.

If you are unsure, have the system checked over by an experience auto engineer.

Regards,

Clive

 

[Chuckie66]

Thanks guys,

video really useful, though the shims I purchased were singular (that was there previousl) and made by H-tec. Didn’t appreciate there were 2 plug sizes 28mm and 30mm, possible I used just the 28’s. https://www.eurocarparts.com/ecp/c/Porsche_Boxster_3.4_2007/p/car-parts/brake-friction/brakes/brake-accessories-and-brake-fitting-kit/?101339030&1&3458436d80c4b156365d1a6b6279f43d0d08a285&001335
Should/could i use the double shim on the rear? And where best to source?

in event of reusing the shims, what purpose does the sticky shims provide? Presumably still need them to stick to the pads? What glue could be used? Or instead of gluing them to the pad use normal copper grease or Optimal - that’s what I’ve always used on my other cars all of which had no shims.

BTW A bit of firm braking solved the glazing, well until the next stop start traffic jam... discs were new so hopefully they aren’t warped.

 

[Chappelle]

FWIW I was brought up to put copper grease between pads and pistons to stop squeal. Also around hubs and on wheel bolts to ease wheel removal

 

[richardjjs1]

Not sure why you should not fit new Disc as originals are very cheap from Euro car parts
Front Discs have them - they push into calliper
Rears do not have them as standard
LIght covering of Copper Grease if they squeal

Not sure why you would not do the Discs as they are cheap from Eurocar parts (Loop for 50% Discount on line) Genuine Brebo

I paid 230.00 with 50% off EBC a little more

 

[Chuckie66]

FWIW I was brought up to put copper grease between pads and pistons to stop squeal. Also around hubs and on wheel bolts to ease wheel removal

I’d always used copper grease on previous cars (bmw’s and Audi’s ) between pads and piston, but now with a sticky shim between the two I wonder whether the loss of stick is causing brake squeal st low speeds of 10mph.

My options are stick the shim to the pad with some glue, or just put in copper grease (or equivalent) between pad and shim, or buy new shims and hope they stick better To the pad.

Btw pads, discs and shims were new, and clean when originally assembled.

 

[chrishak]

I refitted the old shims without adhesive and there is absolutely no squealing whatsoever. Happy with that because I reckon that fitting the pads with new adhesive-backed shims in place must be a PITA..!

 

[T911UK]

The shims need to attached to the back of the pad to work! If they arent attached they arent doing anything and uou may as well throw them away

When the piston goes back into the caliper the shims pull the pad off the disc, its the pad just touching the disc that makes the noise.

I would use a good double sided tape, 3M or like. The pad needs to cleaned wiyh a solvent first.

Standard cars dont have shims on the rear, S cars have the 28mm and 30mm

They can weld themself into the piston so copperslip or the like is a good move on the spider/piston

 

[Lancerlot]

Personally, I would be disinclined to use a grease with any copper content on brake components as it has been known to interfere with ABS systems.
Regards,

Clive

 

[Chuckie66]

Put in new shims and braking all good now
Worth pointing out, on the Boxster S, the rear brake requires a shim size of 28 & 30 mm shim on each side of the caliper. So 4*28mm & 4*30mm.

 

[Lancerlot]

Here's another reason for not using copper grease. [] https://textar-professional.com/textar-training-center/the-use-of-copper-grease-on-modern-brakes/
Regards,

Clive

 

[vitesse]

In all the years I've been working on cars of all types,never found any problems using copper-ease-whereas without it ,impossible to get wheels off hubs on the roadside after a few months.

Technical arguments don't always hold out in practice or are outweighed by practicallity.
Also where can one buy their ceramic anti seize compound-easily?

Just of course my experiences.

 

[Briggy]

Anyone know why the shim edges are kind of chipped, around the edges? I know they're not damaged as they're new (just about to fit) and also stock photos show the same thing, but I was wondering why that would be the case?

Cheers,
Bryan