Now that I seem to have the oil consumption problem fixed it seemed like time to
get back to the braking problems that were bugging me a short while ago. I was
unable to bleed/adjust/balance the rear brakes. Turns out that the culprit was
a kinked brake line, right under the hold-down strap so as not to be
noticeable. After I replaced the line I discovered that the left rear adjuster
was frozen solid. Rather frustrating since I redid the brakes when I swapped
the axles in April.
Last night, inevitably, I broke the square tang off of the adjusting
screw. Not a total disaster, I was able to salvage an adjuster from one of the
old axles. Finally got to use the BFH impact wrench that I bought from Sears a
few months ago. I'll be darned if it didn't loosen the drum retaining screws!
Managed to swap out the adjuster and started reassembling the brakes when
something didn't look right. The shoes are asymmetric, i.e., the linings are
not centered on the shoes. There is more shoe showing at one end of the lining
than at the other. Sonuvagun, the old leading and trailing shoe idea. I tried
to apply a whole bunch of Physics 101 to determine the ideal configuration, but
I gave up. Decided to dig out Haynes and find the answer. Hmmm? How about
Bentley? Hmmm? How about Porter? Nope. Seems that each source shows drawings
or photos of a brake system where one can see that the ends of the shoes going
into the adjusters are one of each. I finally figured out, after studying the
graphics, that each photo/drawing shows a brake system on the right side of the
car. I was working on the left side so I used the mirror image.
Long story short -- mine were wrong. The part of the shoe with the most metal
not covered by the lining, i.e., the part with the tapered ends goes into the
adjuster side toward the front of the car. Bentley's Fig. 9.9 on page 152,
Moss' exploded view on page 37 of MGB-11, Bentley's exploded view on page 215
(1975-1980 version) are ALL showing the orientation of the shoes on the right
side of the car. If you're working on the left side of the car, swap the shoe
orientations.
Sorry to have been so wordy on this one. I'll bet that Barney can give us a
good explanation about why this orientation is necessary to get the proper
braking action.
Maybe Moss could include a caveat on their brake parts page.
Bud Krueger
52TD (did the 110 mile/day commute for two weeks)
77MGB (getting ready for 1000 mile trip)
|