Brake pedal

[HJSY50B@prodigy.com (MR MARK SHIMONKEVITZ)]

OK, since we're on the subject of brake pedal adjustments:

Anyone have any luck keeping the pedal assembly from moving? There's 
a bolt that holds it to the floor. You adjust this bolt, with the 
slot in the pedal assembly base, to properly position the pedals. If 
the assembly moves to far forward, the brake pedal angle is such that 
the pedal is back a couple inches from the gas pedal. If adjusted 
properly, the brake pedal is parallel (more or less) with the gas and 
clutch pedal.

Even if you brakes work well, it adds excitement to have to bring you 
foot towards you 2" before you can even reach the pedal! I've 
adjusted this several times, and it alway slips back to the old spot. 
And the bolt is tight, both when I set it, and when I go back to 
check it later. Yes, I've used lock washers, Loctite, etc. Am I doing 
something wrong?