I have a 2002 X type 3.0 with 72,000 trouble free miles but for the last couple of years there will be times when the brake pedal will incrementally drop while braking and then make a grinding noise while stopping. The car has been looked at a couple of times at the Jag dealer and they could not find anything wrong with the break system. The car always stops fine and the pedal never goes to the floor but if you feel it dropping if you lift off the brake and then press again it will work normal. This only happens occassionally...the car does have Akebono ceramic break pads...this is the only changed from production. Any similar issues or suggestions?

 

my guess would be the vacuum line at the booster. The grinding is odd though, do you fell the grinding through the pedal or hear it or both.

 

Thanks for your reply! I can both hear and feel the grinding. They did replace a vacuum line at the dealership to see if this was the issue but nothing changed.

 

Weird, I'm thinking it has to be caliper related, no leaks or loss of fluid in the master cylinder? The grinding could only be metal on metal if you feel it through the pedal, check all your rotors for scoring, dealer might be brain-dead or something.

 

Got a stupid question for you, where is the "vacuum line at the booster"?

 

There is a round thing attached to the drivers side firewall, by the brake reservour. right behind the radiator reservour. That is the vacuum brake booster, there are vacuum lines coming off it. It is probably the most common area for a vacuum leak.

 

I have been listening closely and when it makes this noise...after you take off within a few seconds you will hear and feel something that sounds like a "release". This leads me to believe you are on the correct track of a caliper issue. It may not be closing correctly as it is applying the brake and then releasing later...it is not as if it is frozen or stuck on the close position because I would feel the resistance when i take off.

 

Did you ever get to the root of this problem? I have a 2004 XJ which is doing similar things occasionally. There seems to be a slight give in the brake pedal and a mild "grinding" sensation working its way back up through the brake pedal. The DSC and ABS lights then come on but the brakes still work fine. The DSC light then goes out of its own accord. When I next start the car next day, the ABS light is still usually present but goes out soon after I start driving. Probably happens one in every five times I drive the car.

 

@Flingel 11 year old thread AND this is the X Type Forum (X400), probably best if you go to the correct forum to ask/search

https://www.jaguarforums.com/forum/x...-x350-x358-28/