Hi All,
I originally sent this message back on Feb. 20. Due to the list being
down, I am re-posting. Some may have seen this appear on other lists.
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As some of you may remember, about 2 years ago, I was working on
having correct pistons (length and diameter) remanufactured for early
disc brake cars with tandem master cylinders. At the time, there
seemed to be a good amount of interest in having this done, so I have
followed up on it.
Many of you know that, when disc brakes were first fitted to
Spridgets, the tandem master cylinder was resized from 7/8" down to
3/4" on the brake AND clutch. Dual piston rear wheel cylinder were
also introduced around the same time. This production of tandem
cylinders was relatively short-lived (1962-1967), but used ones seem
to be extremely rare and many of them that have survived were resized
with oversize bores and oversize pistons. These required custom sized
seals, so stock seals will not work properly (if at all) on those
"Roadstar" units. 3/4" master cylinders are NLA from MOSS or any
other sources I know.
I have already heard back from a number of people who are interested
either in restoring their oversized Roadstar or 7/8" original MC's to
3/4" bore for their disc brake conversion.
I have been working on this in conjunction with a very reputable and
knowledgeable brake specialist, so I have utmost confidence this will
be done right.
Converting to 3/4" pistons will result in a 36% reduction in pedal
force. This will also be the case for the clutch pedal. Price per
piston will depend on the first run quantity but is not expected to
exceed $50 to $60 each. If you need or want it done at the same time,
brass sleeving/bore resizing your master cylinder is available and
will be $120. This is the same price as sleeving a 7/8" and you can
combine 3/4" and 7/8" bores, if you like, for the same price. 3/4"
bore master cylinders also used shorter push-rods, but these pistons
are designed to accommodate both short and long push-rods. Pistons
are available commitment to sleeving at the same time.
See link on my Tech tips page for more info and pix:
http://www.gerardsgarage.com/GarageContent/Tech/DBrake/BrakeMC.htm
I currently have 22 pistons reserved out of the production of a batch
of 100. Depending on interest, this may or may not be the only
production run, but I would like to hear from anyone who is
interested. If you have or plan to upgrade to disc brakes and want to
keep the original master cylinder this is your opportunity to
complete your system as it was originally designed and installed.
Installing a later pedal box and master cylinder is of course an
option, but requires a some frication/modification and additional parts.
Please feel free to post any questions you may have on list for
others to see and reply to, but if you message me on list, please CC
me as well as I only get digest version posting and may miss your
reply. My email address is pixelsmith@gerardsgarage.com.
I look forward to hearing from many of you on this issue.
Gerard
http://www.gerardsgarage.com/FS_Garage.htm
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