This is just a thought but if the rear brakes were to be out of adjustment on
a single master system it would take so much fluid to move the rear shoes,
very little would be left over to run the front brakes. Also excessive runout
in the front rotors can cause the pads to be pushed back into the calipers
causing diminished braking. If it were my car I would 1. Adjust the rear
brakes until locked and back off ONE notch (Bentley manual). 2. If the
problem still exists check the front rotor runout.
Good luck, hope this helps,
Rick Ewald
67 MGB
In a message dated 3/30/99 12:56:02 PM Pacific Standard Time,
xyzabcde@earthlink.net writes:
> Hi again,
>
> 20 years ago, when I first discovered this problem (how could I miss it?) I
> was
> told that it was "the nature of the beast" so I suffered along. Since I
was
> in
> Southern California, I didn't suffer often. Just like a leaky roof, I
> couldn't
> fix it when it was raining, and when it wasn't raining, it wasn't a
problem.
> It
> was on my list of things to fix "one of these days." I'm not sure if I'm
> relieved or not to find out that it's only my car and not a design defect
> because now I wonder what's wrong with it.
>
> There couldn't be a problem with the pads or shoes because I've had quite a
> few
> sets in the car over the past 200K miles--some metallic, some not. Since
> Kelvin
> (and Matt Kulka) suggested that the front brakes could not be applying
> enough
> braking, it dawned on me that I've put fewer sets of pads on the car than
> shoes. In fact, I have a spare set of drums that I have turned before
> replacing
> rear shoes, but in 200K miles, I've never needed to turn or replace the
> rotors.
> Yikes!
>
> I did rebuild the calipers and replace the rubber brake lines about ten
> years
> ago. The brakes didn't work any better after that but they've always
worked
> great, except when it's raining. I promised myself that I'd replace the
> master
> cylinder on principle when it got to be 15 years old. I don't remember if
I
> did
> or not, but there's no brake fluid dripping on my shoes and this wouldn't
> effect
> just the front brakes anyway.
>
> The only other possible option is a blockage in the lines to both of the
> front
> brakes. But there is no line that only goes to both of the front wheels!
> There's a single line from the master cylinder to the splitter/brake light
> switch that feeds the entire car. At the splitter, there are two separate
> lines
> for each front wheel. Since the car has never pulled to one side, both
> front
> lines must be restricted the same amount. I just went out and looked and
> both
> front brake lines look fine. Is it possilbe that the steel lines are
> corroded
> internally? Could the splitter be clogged?
>
> It looks like the next course of action is to disconnect brake lines one by
> one
> and look for diminished flow. If that doesn't work, maybe I'll install an
> apportioning valve so I can adjust the percentage pressure to each end. Or
> maybe I'll just crimp the back brake line :-\. Hey, *that's* the
problem--I'
> ve
> never had my car towed! ;-)
>
> Thanks for the advice, everyone. You've pointed me in the right direction
> and
> now it's just a matter of ferreting out the problem.
>
> Thanks!
> Denise Thorpe
>
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