I've only recently noticed my brake pedal comes all the way back up except for the last 1/4-1/2" or so. I can either pull it the rest of the way with my foot, or let it be for 5-10 seconds and it moves out fully. My pedal feels great aside from this. It's smooth, firm, and otherwise feels like a pedal should. My brakes work well, too. I swapped the master cylinder a month or so ago and flushed the lines. Pads have decent life left in them as well. As soon as the pedal is released, the car will try to move if in gear, so the calipers are releasing. Again, everything seems normal and the only reason I've noticed is my boss was behind me on my way to work and said my lights were doing something weird, and since then I've paid attention to it. Is my servo on the way out, or can the pedal be adjusted? My only real concern is my brake lights don't turn off until 5-10 seconds after releasing the pedal, which in traffic is probably infuriating to the cars behind me. Any input is much appreciated!

Edit: I have seen some other threads similar to this, but it seems they have braking issues as well.

 

I used a motive pressure bleeder on my 90 the other week, pretty well as you'd use it on any other car. I was a little skeptical that the rear would bleed, but they did. Pedal seems fine, little more foot effort than say my Lincoln Town Car but I assume
that's between normal and a matter of pad choice. Feels about like a Mercedes of the era. Car stops straight and well, though I haven't beat on it.
It was ok prior to mind you (pad change) but the fluid seemed to go from darker to
light clean new fluid as it normally does.

One of the best things I ever bought was a pressure bleeder, I always go buy a cap adaptor whenever I get another car with a different one.
Or a friend or family member or neighbor does...

 

I would first check under the dash to see if maybe one of the multitude layers of Stuff in there has settled and got partially in the way but moves away again? Its kind of a pain removing the bolsters but could be worth it. Good luck!

 

Hi Civicalized,

We assume you are asking about the 1989 XJ6 since you have posted in the XJ40 forum.

The XJ40 uses hydraulic brake power assist, so it does not have a conventional vacuum booster with a large pedal return coil spring built into the booster. Instead, the brake pedal is returned to its static position by two small torsion springs, shown in the diagram as parts 11 and 12:




The springs are no longer available from Jaguar, but you might be able to remove your springs and re-tension them by spreading the arms apart so they will bring your pedal all the way up again. It may also help to lubricate the pedal pivot pin, part 7, and pivot bushes, parts 5, with white lithium grease or similar (not a light solvent oil like WD40 or penetrating oil).

Cheers,

Don