Fading brakes
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Joined: Jan 2006
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Fading brakes
The brake pedal began to require pumping and it evolved into the pedal slowly fading all the way to the floor when stopped at a llight for example. Unless I re-pumped. I can find no leaks in the system and I bled them yesterday after which the pedal 'caught' higher but continues to fade - a bit more slowly but, without pumping, will still fade all the way to the floor at which time the red 'brake' light comes on on the dash.
My first impulse is to assume I didn't do a very good job of bleeding (i've done it many times, though) but before I redo, is there anything anyone can suggest I look for as an alternative cause. (Yes, pads are good.)
Jim
My first impulse is to assume I didn't do a very good job of bleeding (i've done it many times, though) but before I redo, is there anything anyone can suggest I look for as an alternative cause. (Yes, pads are good.)
Jim
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Joined: May 2002
Posts: 24,337
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Probably.Fade is when the pads overheat.
Pedal dropping is either boiling fluid or a bad m/c. It's hard to boil the fluid before you get pad fade unless it's really contaminated.
Also if the wheels get very hot and your gas mileage is bad, the booster pushrod could be dragging the brakes and overheating them.
The pedal is rock hard means you have no air in the lines.
The dash light means one of your circuits has much lower pressure than the other.
You've got a bad m/c.
In my experience, bad master cylinders tend to bleed down easier when the fluid is warm and under moderate pedal pressure. Cold fluid is thicker, and pushing the pedal hard can swell the master cylinder seal causing it to feel like its ok.
Fluid leaking past the primary seal will just go back into the reservoir. Don't get a rebuild kit, toss it in the garbage and get a whole new m/c.
