My 97 Grand Caravan brakes worked fine. Then on one real cold day the pedal
started going almost to the floor. I pumped it a couple of times and it was
ok. It does that every time. The fluid level is ok and it stops even without
any pulling. Also, I didnt see any leakage on the backing plates or
concrete. Does this sound like the master cylinder and how can I make sure
before I change it? I have replaced the front pads and rear shoes within the
past 10 or 12 thousand miles.
I think Im on the right track but would like any advice or opinions before I
Thanks for any advice.
One way to tell you've got a master cylinder in need of repair is to sit
with your foot on the brake pedal (engine running, for the boost), as though
you came to a stop. If the pedal sinks slowly, the master cylinder needs
One thing more:
The brakes will stop the car at any time-even without pumping. It stops as
if either the front or rear system is not working. If its pumped up, the
pedal is at normal height/position.
Thanks for any help
Considering that modern cars have dual braking systems (how many wheels are
on each line depends on the manufacturer), it sounds like one of the dual
sections of your master cylinder is shot. Or one of the systems has too much
air in the line...
Could be that the dual circuit master cylinder is so messed up that it won't
even report that it has a problem. Suffice to say, you really want to have
that master cylinder looked at, even if it's just a massive need for
bleeding the system (and checking the warning light circuit). (Note: many
mechanics hate bleeding brakes [as a standalone job] -- it's labor intensive
and they can't charge as much for it as they can for installing new parts.
If the new parts require bleeding the system, they make up the money on the
labor in the markup on the parts...)
This is an interesting problem , let me know what you find. I have a
friend who is a mechanic who has this problem on a '95. He replaced
everything, used the scan tool, bled them according to specs, and still
the pedal would go to the floor. I drove it, I was going to buy it but it
wasn't a long WB model. Stopped fine, just every once in a while the pedal
would go right to the floor!
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