Alan Duff wrote:
Just bought a 83 300D. The brake pedal is rock hard and only moves down a
quarter inch or so and the car is slow to stop. The brakes don't seem to
drag. Don't recall having this type of problem before. My thoughts are
1. Stuck piston in a brake caliper
2. Stuck master cylinder.
Any ideas?
The vacuum brake booster is NOT working. Usually the problem isn't the
booster but the vacuum supply to the booster - often a leak,
occasionally the vacuum pump.
First test. With engine off, and foot pressing on the brake pedal, start
the engine. The pedal should drop about 1/2" and feel "softer" as vacuum
builds over a few seconds. If it doesn't the the booster isn't working.
If the engine stops when you turn off the key, there is at least SOME
vacuum (as the shutoff valve is vacuum operated) and I'd start to
investigate the line from the vacuum pump to the brake booster.
It gets more complicated from there depending on what you find.
Check this link:
http://skinnerbox.steaky.org/Service/W123/Index/Groups/43BrakeBooster.htm
Marshall
--
Marshall Booth (who doesn't respond to unsigned questions)
"der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 181Kmi,'87 190D 2.5 199Kmi, '84 190D 2.2 227Kmi, '85 190D 2.0
159Kmi, '87 190D 2.5 turbo 234kmi
Diesel Technical Advisor MBCA, member GWSection
http://www.dhc.net/~pmhack/mercedes/mbooth1.htm
