[Hakon]

Hi,
Changed all my discs and pads recently,
Bedded in the pads, all feeling good, much better than stock.
Just a couple of days ago, the brake pedal now has longer travel.
The brakes still work but it seems as if the pedal needs to be keep being pushed to the floor and doesn't really harden up.
Brake master cylinder failure coincidence or boiled fluid on bedding in, although don't think so ? Or perhaps just in the head cherrsagai





Gervase

 

[chowdah]

What have (haven't) you done with the fluid?

 

[Hakon]

Hi,

New fluid bled through before changing the discs and pads to avoid old fluid being pushed back and bled again after install of discs and pads.
But, the feel was fine for maybe a week and then the long pedal feel came in. Not losing any brake.

 

[Vector57]

Basic tests of your master cylinder and booster:

-1 With engine off, repeatedly pump your brake pedal till it remains at constant height. While applying hard, constant
pressure on the brake pedal, the pedal height should remain constant. If you notice the pedal slowly moving toward
the floor by any amount, the master cylinder piston seals are leaking (bypassing). Master cylinder replacement is
required.

-2 Repeat the above, holding steady pressure on brake pedal and start the engine. The brake pedal should drop
significantly. If it doesn't, the brake booster diaphragm is leaking and will require replacement.

If either need replacement, you must have the entire hydraulic system bled using a GT1 (or equivalent), since the
brake lines at the master cylinder have been opened. This introduces air upstream of the DSC/ABS hydraulic
module and there is no way to remove it without activating the high pressure charge pump and then cycling
through all of the control valves on the hydraulic module.

Regards,
Alan

 

[Hakon]

thanks for the reply, just what I needed to read. Will check it out.


Gervase