Brake Servo

[kevtheskin]

Hello everyone.

I have a Wrx 52 plate Wagon and the mechanic at work says my brake servo is failing or not working. What would be the symptoms of a faulty servo?. He found this fault when he was freeing of my sticky caliper. I dont feel any differance in my braking?.Or has it been like that for so long that I dont notice. The pedal is stif until I turn ignition on then it drops slightly and I slam on brakes and I stop . Any info in what to expect feel etc.

Cheers Kev

[badbaz]

The test you carried out of starting with foot on the brake (having pumped the pedal before starting to deplete the vacuum) is a good way to check. If you start the engine and run it, then stop it, wait a minute or so, pump the pedal, it should become very hard in 3 or 4 presses - if it seems hard immediately then you may have a vacuum leak. HTH

[kevtheskin]

The test you carried out of starting with foot on the brake (having pumped the pedal before starting to deplete the vacuum) is a good way to check. If you start the engine and run it, then stop it, wait a minute or so, pump the pedal, it should become very hard in 3 or 4 presses - if it seems hard immediately then you may have a vacuum leak. HTH

Thanks will try that tomorrow. Tell me if the brake servo is goosed is it bad to still drive her and is it expensive to put right?.

Kev

[badbaz]

If it doesn't work at all you would find it very difficult to stop without knowing for sure you had a major problem. It could have a leak, which would reduce it's effectiveness. Not particularly expensive - plenty newage cars being broken so you should get a replacement pretty cheaply - fitting would maybe take an hour or so - never done one on the Impreza yet.

Yours is definitely working to a degree.

[arch]

I have a master cylinder and servo from a very low mileage blob STI available if you need it.