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Recommended Posts

the brakes on my 99 C4 tip feel weak whenever i use them from 50mph and more. they dont give the expected braking power proportional to the pressure i apply on the pedal. I recently just flushed the brake fluid using the motive bleeder hoping to improve things, but the brakes still give me a scare when i stop from speed. the rotors and pads seem ok as the car has run under 20,000 kilometers. any suggestions on

what to do next? TIA

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  • Admin

First I would have the vacuum booster tester. If it is not that then...

How old was the brake fluid when you changed it?

Were there any signs of water (or rust) in the fluid?

It could be that your caliper pistons are corroded and sticking not allowing full movement. If so, Porsche sells caliper rebuild kits.

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loren,

i got the car used and there are no signs that the brake fluid was replaced by the original owner. when i did flush the fluid it was dark but there werent rust or water. how do i check the vaccum booster and can u dive me the part number for the caliper rebuild kit? thanx to all who replied

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  • Admin

One way you can test the booster is to start the car and let it idle for a minute or two. Then press the brake pedal and hold it. The brake pedal should remain firm and not depress any further - if is does you likely have a leak in the vacuum boost.

Do you have any experience in rebuilding calipers? If not let a shop do it.

You will need to inspect the parts (pistons and bore) as well as the inner seals and replace them as needed.

MY99 C4

Front caliper repair kit: 951.351.917.01 and 951.351.917.00

Rear caliper repair kit: 951.352.917.01 and 951.352.917.00

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i recently found from the archives that the rebuild kit for my 996 calipers only include outer dust boots, i assume ill need more than those as i feel that the pistons might be sticking. and that i have to buy a new caliper if the inner seals need to be replaced. I would appreciate help from those who found the inner seals from other sources before i proceed in rebuiling them TIA.

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