Bleeding/filling a Lambretta Hydraulic Front Disk Brake
Bear in
mind this is a real bodgers way to bleed a disk brake and after
many hours of spraying brake fluid everywhere I personally found
it worthwhile to have the right tool for the job. For example
the Gunson eezi-bleed @ approx. £15 can be adapted to work and
takes a lot of the frustration out of this crappy job.
Gunston
eezi-bleed
Attach
the pipe to the bleed nipple & give it 1/2 - 1 turn.
Now
the hub is fitted and connected ensure everything is tight and that the seals
have been fitted to clamp the hose attachment to the caliper. Lay newspaper
under the tyre.
Either
dismantle the bleeding kit or use a section of rubber hose to attach to the
bleed nipple. I used half the bleeding kit as it had clamps to go over the nipple.
Now
the hub is fitted and connected ensure everything is tight and that the seals
have been fitted to clamp the hose attachment to the caliper. Lay newspaper
under the tyre.
Either
dismantle the bleeding kit or use a section of rubber hose to attach to the
bleed nipple. I used half the bleeding kit as it had clamps to go over the nipple.
To
lift the front of the scooter up so you can remove the hub, stick a length of
wood under the stand.
Fit
and tighten the bolt with new seals in place. In this case I have a Goodridge
connector (BK599-03C & BK594-03C needed for both ends)
Now
the hub is fitted and connected ensure everything is tight and that the seals
have been fitted to clamp the hose attachment to the caliper. Lay newspaper
under the tyre.
Either
dismantle the bleeding kit or use a section of rubber hose to attach to the
bleed nipple. I used half the bleeding kit as it had clamps to go over the nipple.
Locate
the bleed nipple on the caliper. This should have a rubber dust cap over it. I
brought a cheap (<£5) bleeding kit and fitted one end over the nipple, the
other into a container (brake fluid is nasty stuff, dispose of wisely).
Remove
the lid of the master cylinder, being careful to keep the seal and retaining
cap.
Turn
the nipple nut half a turn using a 8mm spanner.
Now
this is the main bodgerism part! I brought a poxy 10ml syringe (you
need a 30ml to fill the system in one go, bigger the better)
Undo
the bolt holding the hose to the caliper and prepare to catch any residual brake
fluid.
I
attached another length of tube to the syringe using a couple of twists of
copper wire. Then fill this with a quality DOT brake fluid, removing as
many air bubbles as possible. Attach to the other length of hose and fill the
system VERY SLOWLY (brake fluid strips paint easily!)
The
bolt that holds the hose should line up with the groove in the hose connector
i.e. hole should not be half way down bolt.
Keep
an eye on the level in the reservoir and check that all bubbles are expelled
through the 2 small holes at the base of the reservoir. Once
filled, tighten the bleed nipple and replace the master cylinder lid.
Spot
the knackered seal! Replace these as a matter of course.
Now
give the lever a couple of squeezes to
prime the system and take it off the stand to test it out. If it's soft/ spongy with little or no braking
power then there's probably air in the system - go back and try again! You
maybe lucky & loosen the bleed nipple slightly to expel any air, then
re-tighten and test again.
