ldv dodgy breaks

[iaith]

I have a ldv pilot van, and the breaking has recently become stiff and not so effective.
would anyone have an idea what the problem is?

Cheers. Mark.

 

[Burnerman]

If the pedal has risen a little higher, and the brakes need much more pedal pressure to apply them, it sounds like the servo assistance is failing....first check the air pipe from the servo to the air evacuator pump for splits etc.
John

 

[iaith]

Thanks for the reply john. The air pipe to the evacuator pump seems to be in ok condition . If the servo is gone . is it something that can be repaired or does it need to be replaced? Cheers

 

[Burnerman]

They aren't repairable, mate.....here's what you can do to test them.
Take off the pipe from the evacuator pump to the servo. Start the engine.
Can you feel sucking when you put your thumb over the end of the pipe?
Next test - engine off. Press the brake pedal a few times....the pedal should rise to the very top of its travel and become stiff. Keep the pressure on the pedal with your foot, and start up. If the servo is working the pedal should fall a small way down.
Thats about all you can do to test this system....if this checks out ok then you could have a brake master cylinder problem, but thats way off yet.
Be lucky!
John

 

[iaith]

Took the pipe off at the servo , there was very little/no suction in the pipe. i then tried the second test you suggested, the break was already stiff and didn't move at all when I started the engine.
Cheers. Mark

 

[Burnerman]

Therefore, Mark, it could be reasonable to assume that its the evacuator pump thats called it a day rather than the servo - at this stage anyway.
Petrol engines rely on inlet manifold vacuum to work their servos...diesel engines dont have this which is why they have a mechanical vacuum pump. No vacuum means no servo assistance!
I must confess though, I've never taken one apart so I don't know if internal spares are available.....I doubt it. Some evacuators are driven direct from the camshaft, others are belt drive. I don't know which system your van has.
John

 

[andyandy2]

Check the pipe from servo to pump, it may have a small pipe branching off it, sometimes used to operate heater controls or whatever, you may have a leak there.

Also while doing the test described above, holding the pedal start the engine and then increase the revs, see if the pedal moves at all, a worn pump may produce more vacuum at higher revs

 

[iaith]

Thanks guys. I really appreciate your help. I'll get on the case straight away. Cheers