>Whoa there, fella! Shame on you for requesting tech data on a safety
>related auto system. This repair should be left only to certified
>professionals. :^)) BTW, what's the problem?
>GM
-----Original Message-----
>I was looking at the Tech Central Page (I downloaded the whole
site, minus
>pictures, a while ago)
>It talks abouta master cylinder kit... I imagine this might fix
my
>problem. What all does a master cylinder rebuild entail? I
imagine it
>requires honing the cylinder? How expensive can master cylinders
be?
>Thanks again
So, to get by the sarcasm a little, here is another job best left to the
pros. And the main reason is it is just plain cheaper for them to do it.
I can get rebuilt, tested AMC master cylinders for $35-40 (RC Truck Sales,
Thatcher St,. East Bridgewater, Mass. 02333) as well as rebuilt and tested
starters, alternators, water pumps, etc. Also a large selection of brake
components, aftermarket body panels (no Bricklin or AMC though), etc.
To answer your question about rebuilding a master cyl. Yes, they have to
be honed. However, too much honing will increase the size of the bore,
decreasing the ability of the "cups" to seal. Some Master Cyl, though not
Bricklin, have stepped cylinders, piston stops, pressure switches, etc that
would require special tools. There are also check valve in the area the
lines attach, most notably residual check valves that holds pressure in the
line (about 10psi). To get the "guts" out you will need a set of snap ring
pliers, and by pushing the piston in and out a number of times it will
eventually come out of the bore. To reassemble, coat the components in
brake fluid (Dot 3 or Silicone, whichever you will use in the system) and
carefully reinstall the parts. Especially be sure the rubber cups don't
expand in the wrong direction.
Master cyls are made with a specific brake system in mind-if it is
disc/drum, one chamber will be larger due to the disc brake piston needing
more fluid to move it, due only to it's larger size. The system is
"balanced" so the movement of the master cyl pistons will move the pistons
at the four wheels the proper amout to equally apply pressure, allowing the
car to stop in a straight line.
Another component to replace when doing the master cyl is the rubber seal
under the cap. Contamnation could cause this seal to swell to twice it's
normal size.
So, to the original question. I'll guess the rebuild kit is around $15,
plus the cap (haven't seen the rubber seal sold separately) and your labor.
Plus you have to "boil out" the cast iron core to remove sludge, etc and
insure all passages are opened. Then your time, and hope the bore is the
correct size as you probably don't have the gauge to check it (usually a
simple Go-No Go gauge). Don't want to sound like an "only the pro's can do
it right" type of person, which you might expect from my last two posts,
but this is a case of simple economics-It's just cheaper and easier to buy
one already rebuilt.
Advice enough?
Thomas M. Benvie
5 Sachem Rock Ave.
East Bridgewater, MA 02333
(508) 378-1423
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