Re: type 44 brake question - long answer

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <3.0.3.16.19981013094942.2f4f689e@n-jcenter.com> Mike Arman writes:

> Spongy, soft brakes: Test one: pump the brakes - if the pedal comes up and
> you can get one or two good applications THEN it sinks down, you have air
> in the brake lines. Getting the air out of the rear calipers is a pain - it
> gets trapped in the area of the pressure regulator (in front of left rear
> wheel) and also in the rear calipers themselves. Just keep at it - pressure
> bleeding works better, but you CAN do this the old way.

Roger's car is the only one I'm really familiar with, and his
proportioning valve is under the master cylinder in the engine bay.

> I was totally successful in ALL of these, but have had NO success in
> rebuilding Audi hydraulic components except calipers. Even the clutch slave
> cylinder wouldn't work for me, and it has only ONE miserable seal! I
> honestly don't know why - it doesn't make any sense to me, and I do know
> what I'm doing.

Yup, I know _just_ what you mean.

> 1. Bleed brakes, carefully, thoroughly. Test, note any or lack of improvement.

Make sure the order is right.  On the cars with proportioning valves
under the master cylinder, the proportioning valve _MUST_ be bled
right after the master cylinder and before the wheels.  It's a 9mm
fitting (!) too.

> 2. Replace pads, check all calipers for leaks and torn seal boots, and rear
> calipers for stuck parking brake levers (common problem - remedy is
> lubrication and work it back and forth repeatedly). Calipers are easy to
> rebuild - fronts are almost trivial, rears are a little tricky - reading
> the rebuild instructions that come with the kits really does help. Bleed
> brakes again if system was opened. remeber to grease the slide pins for the
> calipers. (While you're there, check your CV joint boots.)

Caliper return springs ease off with age.  On the Girling calipers fitted
to the ur-quattro, Ford Granada return springs (# 6141147 & #6141148)
provide more positive action.

> Safety issues completely aside, when these brakes are working properly,
> they are GOOD!!! I'm afraid some airhead in a junk mini-pickup will
> tail-end me - My car stops RIGHT NOW - and I know the brakes in whatever is
> behind me are nowhere near as good, even assuming the driver is at least
> semi-conscious and smart enough to realize that when his entire windshield
> lights up bright red it means STOP, A**HOLE! . . .

Frightened the sh*t out of a tailgating copper a couple of weeks ago ...

--
 Phil Payne
 Phone: 0385 302803   Fax: 01536 723021
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