[Spridgets] A little brake help?

[Dean Hedin]

1) Is the valve in the brake bore of the master cylinder proper?

2) Forget the rod length for a moment. What is really important is 
that there is adequate free play when the pedal is not depressed.
In other words the piston is free to go all the way back out when you let
off the pedal. Once you understand this it is clear that the rod length only
determines where the pedal is situated in space.  Right?

3) When I re-sleeved my master 2 winters ago and later test drove the car
my front brakes also locked up.  It turned out that the caliper pistons
got gummed up from age & sitting too long.  I pulled them apart and cleaned
them up.  What's the state of your calipers?

4) Now is a good time to re-bush the pedal levers if you have not already
done so.

5) Now is also a good time to make a little "dam" in the pedal box 
between the master and the holes where the pedals go through,
This, so that in the future if the cylinder ever leaks (or you spill the can
when topping off) the fluid will not run down the pedals a cause all sorts
of havoc with the pedal pads and floor covering.  I made mine out of a 1/4"
square piece of rubber cut to the width of the box and RTV'd it in place.
If you have ever had silicone brake fluid on your pedals you will appreciate
this tip.

-----Original Message-----
From: spridgets-bounces at autox.team.net
[mailto:spridgets-bounces at autox.team.net] On Behalf Of Mark Haynes
Sent: Monday, June 14, 2010 10:31 AM
To: spridgets at autox.team.net
Subject: [Spridgets] A little brake help?

OK guys,
I rebuilt the tandem master in the BE this winter. Found out that it has the
3/4" master (great, perfect for the discs). I referenced Gerard's treatise
on
the 3/4" vs 7/8" masters, and was a bit confused when I found that I had the
same length pushrods as the drum brake (7/8") master that originally came
out
of the BE. All of the holes were worn on the clevises, as were the pins, so
I
matched the length of the pushrods I removed from the master, with those
that
were laying about and in good shape, cleaned up the pedals and pedal box
from
the BE (with pedal stop bolts!). Bench bleeding went well, installed the
master, bled it out yesterday and took it for a spin.
When the brakes warmed up, they started to bind. So much so that the car
wouldn't move. Got a ride home, brought the van, my eldest AND TOOLS
(DUH!)Backed off the pushrod as much as possible (so its as short as it can
be), as well as the stop bolt, no luck. Opened the bleeder on the front
caliper to relieve the pressure and all was good, towed home with no
problems.
Here's the question- How do I make sure that this doesn't happen without
taking the car out of the garage? Is there a way to tell if the pushrod is
adjusted too long, or is this trial and error? Should I turn 1/2" off of the
pushrod length to match what Gerard shows about the length? The brakes feel
great now, just like the Spit when I was racing. Is the stop bolt position a
major factor, or just an end limit/ pedal positioner?
I understand that this is due to the piston not coming fully out to expose
the
relief hole in the master and allow the pressure in the front brakes to
bleed
back down. Will this be evident in the garage if you pump the pedal and rock
the car?
Inquiring minds and annoyed spouses want to know....