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Master Cylinder and Caliper Rebuild ?

To: <spridgets@autox.team.net>
Subject: Master Cylinder and Caliper Rebuild ?
Date: Thu, 9 Feb 2006 09:48:34 -0500
Hey, Guys,

    I need some advice on master cylinder and caliper specs on my 1098 Midget.
My rebuilt units from White Post came back with non standard pistons.
    Master Cylinder Pistons. With the new MC pistons they installed, the push
rods will go only about 1 3/8" into the bore before engaging the piston. With
standard pistons, the rods go in about 1 7/8" to touch the piston. Last year,
I helped a friend do his MGA using an Apple rebuilt MC that initially had the
same condition. We couldn`t get the required push rod effective length. The
thing wouldn`t bleed properly and almost immediately leaked.
    White Post claims they do many of these and never had a complaint like
this. Of course, they say their pistons are correct and they no longer have my
original pistons to compare.
    I know with the MGA, which is similar to the Spridget set up, using the
7/8" bore,  the rods couldn`t be adjusted enough for the apparently longer
pistons.
      If my rods can be withdrawn enough, I think it might work. There is a
little room in the Midget for adjustment, but I doubt if it`s going to be
enough. I would rather resolve this before I start taking things apart. Does
anyone have any experience with this sort of problem?
    I know the rod free-play is essential. Will the longer pistons be made to
work on the Midget by simple rod adjustment as they claim?
    Is there anywhere I can get a set of stock MC pistons, assuming the bore
has not been altered?
       Caliper Pistons. The rims of stock caliper pistons have a relieved
portion, about 1/64", about a third if the circumference, that is supposed to
be at the bottom when the pads are installed. The White Post pistons do not
have this relief. Again, they say their pistons are correct, this is the first
such complaint, and  and the relief area doesn`t matter.
     I admit, I`ve had this car 40 years and I`ve never understood the purpose
of this relief feature, except that it was there to prevent squealing or
vibration, or something.
    Does anyone have any experience with this? Can the non-standard caliper
pistons work with no problems?
     Finially, I still have the units that are on the car. The rebuilds were
the originals removed in 1985. I gather that White Post has my $600, I have
the suspicious rebuilds, and they are content with leaving it at that.
     I hope someone out there smarter than I am can give me some good news
that I`m wrong about this.
     If all else fails, is there anywhere  I might get the other units redone
competently.
     Sorry about the length of this posting.

Bert Shirey.
60 Bugeye/66 Midget 1098




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