In my experience a long pedal that goes short after a quick pump is a
symptom of air. A sympton of slack rears is if the pedal shortens when the
handbrake is pulled up. Bleeding these brakes is a bit of a pain and there
has been much discussion about what technique and tools to use. After
working on the brakes I have found that repeated bleeding always seems to
get some air out, but there always seems to be some left. I have also found
that left to its own devices for a couple of days it will harden up. Now I
know that it would be easy to 'get used to' a long pedal but I drive two Bs
so I have a comparison. The latest recommendation I read was to let the
brakes drip-bleed while you stand by the M/C topping it up rather than
pressure-bleeding. Haven't had the opportunity to try it myself yet.
PaulH.
http://freespace.virgin.net/paul.hunt1/
-----Original Message-----
From: Florrie & Allen Bachelder <bachldrs@swva.net>
To: mgs@autox.team.net <mgs@autox.team.net>
Date: 17 July 1999 02:17
>Hi List -
>
>' Sorry this is rather long, but I need some advice. Back in May I started
>having problems with a soft low brake pedal on my '76 B. It's never been
>firm like my non-servo Bs but it got quite a bit worse. A Roanoke Brit Car
>Resto guy noted the engine idle was affected by the brake pedal and
>suggested it was probably a vacuum leak in the servo. So I sent a servo
>from my '76 parts car off to Apple Hydraulics and got it rebuilt.
>
>While at it, I put in brand new master cylinders (clutch and brake) from
>Moss and on advice of the same guy in Roanoke, flushed out the whole system
>and converted to DOT 5. I did bench-bleed the MC first. Still got a soft
>pedal and within three days my left front caliper was leaking (I've never
>had a caliper leak in all my 15 years experience with MGBs).
>
>' Was about to rebuild calipers (as I've done on other Bs) and discovered
>Advance Auto has rebuilt calipers with OE pistons for $35.99 - with
>lifetime warranty. So I flushed out the system - thoroughly - converting
>back to Castrol GT/LMA DOT4 before installing rebuilt calipers. Again, I
>bled the whole system thoroughly - starting with left rear, then right
>rear, right front and finally left front. There's no DOT 5 left in the
>system.
>
>Still soft pedal. Pads are good. The brake hoses were replaced about two
>years ago, as was the left rear wheel cylinder which I discovered leaking
>at that time. Shoes looked good then. Car has gone about 15,000 miles
>since.
>
>The right rear wheel cylinder is the only item in the system that I haven't
>replaced. It is working and although I haven't had the drum off, there is
>no outside sign of leaking. I am aware that lots of DIYers put rear brake
>shoes on wrong and mine are right - like in the Bentley illustrations. The
>rears are set as high as I can get 'em without overheating the hubs - in
>fact I had to back my left rear off a bit. Even when it was set too high,
>soft pedal.
>
>If I pump the brakes once, on the second application, they feel good. I
>know this is a classic symptom of rears in need of setting up, but that's
>not the problem. At its worst, the pedal may feel awful but the brakes do
>work well - although the right rear tends to lock up first on hard stops.
>
>I even turned the brake light switch in about 1/2-turn - which minimizes
>the 1/8th-inch pedal freeplay and, not surprisingly, makes no difference.
>The pedal does not "leak down" nor am I losing any brake fluid. In fact, I
>swear the level in the reservoir went UP slightly after a 40-mile test
>drive. Could there still be an air bubble in the system...? I suppose
>although it seems unlikely. What could I be overlooking? Should I replace
>rear brake shoes?
>
>Many thanks!
>
>Allen
>
>
>******************************************
> Allen H. Bachelder =iii=<
> Sinking Creek Home for Wayward MGs
> New Castle, VA 24127
> USA
> 540/544-7333
>******************************************
>
>
>
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