1998 XJ8 VDP, 131,xxx miles.

My brake pedal has always seemed low with a long excursion before the brakes "caught". This even after replacing the brakes (local shop) when I first got the car 18 months/10,000 miles ago. The dealer thought the pedal was low, but could find no cause. They recommended basically replacing everything replaceable in the braking system...yeah, right.

Brought the car into the local shop yesterday for an oil change and to check front brakes now making "card-in-the-spokes" noises. They said I needed new brakes, something (calipers?) were frozen. Replaced pads, rotors, etc.

However...after they road tested the car some, ran into a problem. When the car is off, the pedal is high and firm. As was demonstrated to me, immediately upon starting the car, the pedal noticeably drops. This without touching it at all.

They don't want to release the car to me until they find the cause and are satisfied it is safe (one of the reasons I use these guys). Checked all the usual things, no problems found (master cylinder full, fluid clean, no leaks).

Any ideas?

Thanks,

Ian

 

So, you di dnot mention the power booster, which is the only think that should change when the engine starts (vacuum is available), If they know anything about brakes, they know that, though.

 

We only spoke very briefly, I stopped by while out doing errands and they were still working on the car. They did leave a message before they closed (I was out) that they were going to do a gravity bleed on the system overnight.

I will mention the power booster to them tomorrow, thanks.