At 05:10 PM 8/2/99 -0600, you wrote:
>Hey Guys,
...
>Does anyone have any advice relative to rebuilding the front brakes? Long as
>I've got the damned garage ankle deep in brake fluid I might as well rebuild
>'em all...
>
>--Coin Cobb, Las Cruces, NM, USA
>'65 Tiger
Colin,
Recommend you first order 4 new caliper pistons and the
rebuild kit which consists of a square cross section "O" ring
and a dust boot for each side. Get new pads also.
Pull the wire clips retaining the two pins that locate the
pads. ( do not loose the clips). Pull the two pins. Extract the pads.
If necessary pry the pads from the disk with a big screwdriver.
Remove the two 5/8" head bolts with a 6 point wrench or socket.
after a good drenching with PB Blaster. Use of an open end wrench
may round the bolt heads off.
Examine the bolts for bad rust and broken lock washers. Replace
or clean as required. If you remove the steering arm keep track of the
bolts, one is 1/8" longer than the other. Need the proper length in the
proper hole else the dust shield will be dented and possibly the disk
will be damaged.
Remove the caliper from the disk.
Examine disk and clean, have turned or replaced as you see fit.
( To remove the disk, pull the axle dust cap, the cotter pin and Axle
nut. Remove the outer bearing roller and pull the disk/hub off the
spindle. The disk is held to the spindle with 4 bolts. Recommend
replacing the seal when you pull the hub) Check the roller bearings.
clean or replace with new as you see fit. Grease the bearings well
with good grease, ( not the cheapest you can find) and reinstall the new
or turned disk along with a new cotter pin.
Back to the calipers:
Stick a thin board between the two pistons and have your
help press on the brake. One or the other of the pistons will start
comming out. Once you have one piston broken loose some what, secure it with
some sort of a clamp ( C clamp or welder's Vice Grips come in handy). Have
the brake
applied again and the unsecured piston should move out some what.
Remove clamp and board. Wiggle the pistons out. Have a catch pan for the
fluid.
Remove brake hose from caliper or at the fitting near the
frame. Use two wrenches when you disconnect from the frame bracket.
(The bracket is designed to prevent turning of the hose, but if old
and rusty...)
Recommend you get a special wrench for the brake connections. This is a
6 point wrench with a cut out, just adequate to clear the hose. A good
old auto parts store should have the wrench(s). This tool will not
round off the fitting in most cases. I also use PB Blaster on the
connections ( or rusty bolts). This stuff comes in a yellow can and
it works on tight iron parts. ( stinks a bit though).
Remove the dust covers and 2 old "O" rings from the caliper. Clean the rust
and crud from the bores including the "O" ring slots.
Check the lips around the bore of the casting. If they are broken or badly
eroded, then consider $$$ replacing the caliper.
Install the new "O" rings, lubed with brake fluid or red rubber grease.
Install one dust cover into the lip fo the casting. Lube the new piston
( or the old piston if it is not rusted) and slip into the bore. The lip of the
dust cover should be fitted into the lip slot of the piston. Install the other
dust cover and piston in a similar manner. Press ( with fingers)both pistons to
the bottom of the bores. Reinstall the caliper and reconnect the brake line.
Insert the new pads, pins and wire clips. Bleed this rebuilt caliper a bit.
Now go to the other side and repeat the process. You need to have the
rebuilt unit on to allow brake pressure to push out the pistons on the
un-repaired side.
You could use air pressure on both calipers on the bench, but it is easy to
hurt yourself
when 100 PSI hits a 2 to 3 square inches of piston. Keep your fingers out
of the
way if you use compressed air to extract the pistons.
Replace the brake hoses if possible. An MGB hose sort of fits, but
it is
just a little short. Be sure that when replacing the hoses,( old or new)
that the
alignment in the frame bracket does not cause the hose to hit the upper A arm.
Bleed the brakes well. Easy Saturday all day job.
James Barrett Tiger II 351C and others
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