Lambretta Disk Brake rebuild

For details of a proper hydraulic disk set-up for your Lambretta, click here

These pages assume you already have some mechanical knowledge and experience of working with Lambretta engines. The disk brake has already been disassembled. For reference click here for an exploded disk brake diagram.

Time to complete approximately 1.5 hours.

 

DISK LINKS

NOTE: There are 2 sets of disk type fork links available. The angles cast into the middle section are different, being approximately 100 and 130 degrees. TV series 2 have a 30 degree difference in rake compared to all others.

Tools required for the job1. Tools & new parts you'll need for the job include; high melting point grease, brake pads (newfren) two new hub bearings (6201) and oil seals, back plate oil seal and disk nut adjuster retainer plate. Apparently brake pads from a Citroen will fit with a bit of work. 10. Drop the new disk pad into the back plate recess. The steel back of the pad faces you!
Tools required for the job2. Undo the main shaft nut and remove the disk spindle. This will only come out one way. The adjust out the disk pad nut using an allen key. Note the nut would normally have a securing plate behind it which you'd replace.

 

11.  Once the adjuster mechanism has been cleaned and the ball bearings are correctly seated in their respective recesses, then apply plenty of grease to the actual mechanism itself and drop in.

 

3. Once the disk has been opened up the disk itself can be removed (may/may not have a circlip holding it in place - these used to be impossible to find!) This is looking into where the other disk pad sits and you ca see the above adjuster nut. Drop a new pad in here with the steel face going towards the screw thread. 12. Again this will only fit in one way and should be a good fit.
Tools required for the job4. Very uninteresting picture of the disk pad that is moved by the actuater. Again this just drops into the hole in the casting (see picture 10) 13. It's important the key way for the circlip is in good condition and ensure this is seated correctly. Although hydraulic conversions are available these normally use a screw thread. I have seen hydraulic conversions that use the circlip.
5. Once checked or replaced apply plenty of grease to the speedo drive gear and replace the oil seal. 14. Insert the disk spindle, again will only go in one way!
6. Fit the disk this way round. The holes will also only allow the disk to be fitted one way.

NOTE: Never get any grease or oil on the disk brake surface or pads.

15. Reassemble the components for the spindle including top hat and washers.
7. Another uninteresting picture of the speedo drive and oil seal with the disk in place. 16. Don't over tighten the spindle nuts, correct torque setting is 5.5 5.6 kg-m.
8. Once bearings and seals have been replaced fit the top hat and spacer. Bearings and seals are dead easy to replace on the Lambretta front disk brake. 17. Fit the plastic or metal disk windows.
9. This is just a bodgers/riders way of doing this as I did not have/do not use the circlip that holds the disk to the pegs! Bring the two halves together and the disk may have to be rotated through the windows until it's seated on the corresponding pegs. 18. Fit the Innocenti "I" cap and your all done. Refit assembly to the fork links and tighten the fork link nut and bolt to 5.5 5.6 kg-m.