Mechanics in West Kent area for brake issue

[Rayzor495]

Hi all,
Newish to the Porsche Club and looking for a garage who's good with brakes. I had the callipers replaced my 1989 944 Turbo (M030 spec) and there's a knocking sound when you initially reply the brakes after changing direction; the garage seems to think my original brake pads are slightly too small for the new callipers hence the slight knocking sound. The supplier I sourced the callipers from says there's only one type of Brembo calliper fitted to the 944 so I'm stuck between the mechanic and the supplier as to what's correct. The garage also said my old ones look "too corroded" to refurbish which would have been my preference. New callipers from Porsche area around £800 each side! There's also a brake pad light illuminated which was intermittent and the garage said it was cabling as the pads have lots of material on; following their last lot of work, the light is now on constantly.

1). I'm in the Sevenoaks, Kent area and have tried La Rose, Paragon (no success) and a couple other local places, can any of you recommend someone who can provide some expertise on the brakes?

2). There's an "86" stamped near the 20.4873.00 part number, could that be from a 1986 car and hence the issue with my 1989 car?

Any help greatly appreciated

 

[Rayzor495]

Hi, and welcome to the Club and forum.
My initial thought is that if you reused the original pads in your new calipers, the pads may have been filed down by a previous owner (or his mechanic). This sound odd, but it's a common "quick fix" for the problem of pads sticking due to the very common problem with these Brembo calipers of plate lift. There are steel slider plates between the alloy caliper surface and the steel pad backplates, and corrosion forms between the caliper and the steel slider plate causing the plates to lift and bind on the backplates. Filing down the edges of the pad backplates gets everything working. If you then put those pads in a new or refurbished caliper, they will be too small and will knock when applied.

 

[Rayzor495]

Scott thanks for this - kind of makes sense!

What's more puzzling is that the mechanic said he couldn't find the right pads. I'm guessing that if I order new pads for a 1989 944 turbo that should remedy the situation of the brake knock? Probably need them inspected by someone who knows these parts and can make an quick diagnosis and remedy...

Thanks,
Ray

 

[chrisg]

Ray

there are various different size pads for the S2, Turbo (M030) & 968.

For the S2 & Early Turbos and all turbos rear calipers the pads are the same shape, length & thickness and are rectangle in shape.

The M030 calipers (as originally fitted to the 928 S4) are taller and wider and sort of curved if that makes sense - different pad for front and back calipers. The pads for the 968 Caliper or Large Blacks are the same shape as the M030 but just a tad wider so they will fit (ask me how I know...) but have a larger contact patch with ~ 2mm of 'overhang' on the outer edge of the disc

As per Scott - pad lift due to SS vs Aluminium interface leads to the issue you're describing - if you had to purchase new calipers as the old ones were too far gone.... They must have been REALLY bad as the brembo 4 pots are pretty heavy duty and last well - mine have had the plates redone 3/4 times and only recently had to replace the inner hydraulic seals.

C

 

[Rayzor495]

Hi Chris,

Thanks for this, I'm going to get my old ones looked at as it was just the opinion of the garage regarding the corrision, to my untrained eye they look fine to refurbish, I don't see the huge corrosion they were speaking about. Old callipers: https://flic.kr/s/aHsmWvzLWt and the replacements:https://flic.kr/s/aHsmWvzTQo same part number but mine have an 88 stamp and the repalcements an 86 stamp so I'm wondering if it's for the 220BHP model and not my M030 250BHP if the stamp corresponds to model year but mine is 1989 not 1988...they do look idential and the supplier said they are the same and should fit my car.

Thanks for your help and input.
Ray

 

[Rayzor495]

Yes, looking at the pictures the original ones are very badly affected by plate lift. I think to judge whether they are refurbishable you'd have to remove the slider plates which can be tricky - the screws are usually pretty hard to take out and need heat applied.
I'd suggest, as you say, you get some new pads for your model/year of car and try them in the replacement calipers. if they fit nicely without rattling up & down you should be fine. You could speak to a specialist brake refurbisher, I have used Brake Caliper Specialists (BCS), they would probably be happy for you to send the old ones in for assessment before committing to getting them refurbed. Or maybe just get them to look at your photo galleries?
Good luck!

 

[Rayzor495]

Thanks so much Steve, this makes sense, I'll give the refurbisher a call and see what they say. I'll also see about pads, ideally it would be good to find a place that has them on the shelf to try.