I am now on my 3rd x300. Love these cars. I know enough
about them now to be familiar with most?? of their quirks
and weak spots.

I was lucky enough to find a 1995 xj6 British racing green
with 67200 miles on it. Nice ride.

However... this car takes MUCH more foot pressure to stop
the car! Perhaps twice as much - tough to tell. Is it
possible that a brake booster can be just "tired" -I always
thought they worked -or they didn't. Can the wrong pads
cause excessive brake pedal pressure? What might other
factors be? Thanks so much for your help. John

 

Air in the system, bad brake fluid (too old), bad pads, air leak in the hose to the booster, sometimes bad brake hoses (broke inside)

 

You could be right about the booster. I do remember replacing some of them years ago but usually for a honking hooting sound from the diagram. I would first check the booster vacuum line and the check valve. Make sure the connection in the intake is clear. Anybody else?

 

Wow. Impressive response time. The "other" jag site takes sooo much longer to get anyone to chime in.. I will go and check those now. Thanks.

 

PS: what would constitute "bad" pads? The pads were just inspected and they are only 20% worn..

 

Different friction material does change pedal feel/effort, so "bad" in this case would be a very hard friction material.

Agreed on checking vacuum supply to the booster.

A booster can be partially faulty. They're not entirely a go/no go proposition. A small leak or faulty reaction valve in the booster can cause low boost....although the former might be more likely to cause low assist/hard pedal on the first stop and then be fine after vacuum is replenished.

Cheers
DD

 

I have a stack of boxes with faulty boosters from X300s that suffered from the same faults as BlackX300VDP states. If the leak is significant, then the booster will not operate properly. You might even hear a 'hissing noise' from the brake pedal area or in the engine compartment.

bob gauff