Brake performance is declining..., pedal is losing its stiffness Options

[Aaron Cox]

ok... so my pedal was uber firm 3 months ago.....and just the other day i dont feel all that confident in my braking ability...i mean it stops... but the pedal is no where near as firm as it used to be....

resevoir is full.... no leaks....anywhere
6 month old SS lines.....
PO's 19mm MC
rebuilt M calipers and
non leaking and one rebuilt rear caliper....

is my MC dying a slow and scary death? i like my pedals rock firm....

oh...btw i KNOW in the future i will be using 986 brakes..... can i use a 19mm MC with those? or will i have to buy a new one at that time (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif)

[mrihop]

The moisture in the fluid hypothesis is interesting because I have also noticed the pedal being a bit mushier and it travels a little lower. I haven't checked if my MC is bad yet. I'll try to get a helper to bleed my brakes tomorrow if I have time. I've been adding DOT 4 to my system as I've bled the brakes in the past.

To check the MC, you don't need to be driving, you just hold down the pedal hard in the driveway, and if the pedal starts to fall, the MC is no good. Bleeding the brakes can be hazardous to the MC if you're not careful. If you press down much lower than you normally push for stopping hard, you'll run the piston in the MC past all the crap that has built up and ruin the unit.

If you want to run bigger than 19mm in the future, you'll need a lot more foot pressure as you'll begin to loose the hydraulic advantage, but you'll also gain a lot more pedal feedback because every little bump in a caliper will be read by your leg.