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.hydraulic_bitsnbobs.JPG (1110139 bytes) 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.proper_bleed_drain.JPG (1593913 bytes)
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.easy_does_it_bleed.JPG (1297670 bytes) 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.hydraulic_bitsnbobs.JPG (1110139 bytes)
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.

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