Help brakes playing up.........

[HARMSY]

People's.....

Back out of my driveway this morning as i do most days, go to put my foot on the break and it hardly moved and the car went straight into the gutter, lucky i wasn't traveling at any great speed so it was just a bump, the brakes felt really hard and like someone had been pumping them when the car was off........I drove a little down the street and they were a bit stiff but loosened up and went almost back to normal......i have noticed it slightly before but put it down to them warming up, but now i'm a little worried......anyone have any ideas what might be up, not gonna be able to get to my mech for a couple of days, so i'm stuck with the pushy for the moment....

The brakes are off a VX clubby so 4 pot fronts and 2 rear.....


Thanks in advance
wazza

[LS1Grange]

checked ya brake fluid level??

On a different thing but might be same principle my power steering used to be hard to turn. It turned out that it was loosing fluid slowly. Once I topped it up it was OK. Might apply to the brakes also???

Definalty somehting not right somewhere along the line. Lets hope ya dont get a flat on the pushy

[swingtan]

Almost sounds like you've lost vacuum from the booster. Try the following...


Park the car, turn the engine off and apply the hand brake.
Pump the brakes until they go hard. You don't need to stamp on them, just apply enough pressure to make them work.
The booster now has no vacuum in it, this is why the brakes are hard, there is nothing to "boost" the brake pressure. With you foot pressing lightly on the peddle, start the car.
You should feel the peddle go down almost instantly as the engine vacuum helps boost the brakes.


That is what good brakes should do anyway. If you don't have any initial vacuum, then you are loosing the vacuum in the booster. This may take seconds, minutes or hours to leak. The quicker the leak, the worse the problem. If you find that driving along there is no issues with the brakes, then it may just be the one way valves that is leaking, this is still not good.

While it's still stationary, give it a bit of a rev and let the throttle snap shut. This will built up the manifold vacuum and therefore the amount of vacuum in the booster. Turn the car off and then have a good listen around the brake booster. Listen for air leaking back into the booster, it should be but if the leak is big enough you should hear it. If it's small it may take all night for the vacuum to leak. So check the peddle first thing in the morning as well.

Normally this sort of problem would just be the valve not seating correctly or failing, but it could also be the diaphragm in the boost that is leaking, or the proportioning valve allowing air back into the booster. In these cases, it's rebuild or change over time.

Simon.

[ssgirl2]

People's.....

Back out of my driveway this morning as i do most days, go to put my foot on the break and it hardly moved and the car went straight into the gutter, lucky i wasn't traveling at any great speed so it was just a bump, the brakes felt really hard and like someone had been pumping them when the car was off........I drove a little down the street and they were a bit stiff but loosened up and went almost back to normal......i have noticed it slightly before but put it down to them warming up, but now i'm a little worried......anyone have any ideas what might be up, not gonna be able to get to my mech for a couple of days, so i'm stuck with the pushy for the moment....

The brakes are off a VX clubby so 4 pot fronts and 2 rear.....


Thanks in advance
wazza

EDIT: Simon beat me to it.

SS :)

[swingtan]

EDIT: Simon beat me to it.

SS :)

Got to be quick..... ;)

[ssgirl2]

Got to be quick..... ;)

Your post was much more informative ;)

SS :)

[HARMSY]

Almost sounds like you've lost vacuum from the booster. Try the following...


Park the car, turn the engine off and apply the hand brake.
Pump the brakes until they go hard. You don't need to stamp on them, just apply enough pressure to make them work.
The booster now has no vacuum in it, this is why the brakes are hard, there is nothing to "boost" the brake pressure. With you foot pressing lightly on the peddle, start the car.
You should feel the peddle go down almost instantly as the engine vacuum helps boost the brakes.


That is what good brakes should do anyway. If you don't have any initial vacuum, then you are loosing the vacuum in the booster. This may take seconds, minutes or hours to leak. The quicker the leak, the worse the problem. If you find that driving along there is no issues with the brakes, then it may just be the one way valves that is leaking, this is still not good.

While it's still stationary, give it a bit of a rev and let the throttle snap shut. This will built up the manifold vacuum and therefore the amount of vacuum in the booster. Turn the car off and then have a good listen around the brake booster. Listen for air leaking back into the booster, it should be but if the leak is big enough you should hear it. If it's small it may take all night for the vacuum to leak. So check the peddle first thing in the morning as well.

Normally this sort of problem would just be the valve not seating correctly or failing, but it could also be the diaphragm in the boost that is leaking, or the proportioning valve allowing air back into the booster. In these cases, it's rebuild or change over time.

Simon.

Cheers for that, i will give all that a go 2morrow before work.......doesn't seem to be a problem once i'm up and going for a bit, worst case what sort of $$$$ would i be looking at for a rebuild or replacement????

[swingtan]

I'd hate to guess..... The last time I looked at getting a booster done was a few years back and it was a VH-40, separate to the master cylinder. I guess it would range from $350 to $550 ? Can't really say.

[HARMSY]

i just can't win at the moment........:bawl: :bawl: :bawl:

see how we go.........