Thread: Brakes

to test the booster. apply the brakes a couple of times with the engine off to kill off any vac left in the booster. put your foot hard on the brakes and then start the engine, the pedal should sink about 1/2 a full pedal stroke if everything is perfect.

if it doesnt sink at all you have no vacuum supply to the booster (which is usually a cracked line or blockage)

if it only sinks a little then its likely to be either a torn diaphragm or a blockage in the atmospheric vent.

Mate, your'e a legend, but if those checks show all is ok with the booster, whats the next step?

Thanks again, Jack

whats your location?

we sit down and have a long hard think....

if its stopping ok and applying all 4 brakes and the boosters working urmmm I suggest some more time in the gym?

my next guess would be that its not working all 4 brakes and you have a crushed or blocked line/fitting.

adding your location is always a good too.

Sorry Guys, I'm in Taupo NZ, if one of you would like to pop over, in return for some work on ollie we can iffer you some skiing, a world class trout fishery and the biggest fresh water lake in the southern hemisphere.

If you find the booster is working, I would look at the brake linings. I assume since you have replaced wheel cylinders, that they are not oily (which could give this effect), but there are two other possibilities. One is that they have the wrong linings, and the other possibility is that the front brakes have been wrongly assembled with two trailing shoes rather than two leading ones.

There is also the possibility of the wrong size wheel or master cylinders, but this is probably less likely.

But I agree with Dave that the most likely is the booster is not working and the test he gives will show the this. If it is a diesel, getting vacuum from a throttle in the intake, incorrect adjustment of the linkage to this will reduce the vacuum and give this problem, as will leaks on the engine side of the throttle.

John

did you get chance to check the booster yet?