px front drum brake problem....

[phil mcglassup]

Hi All,

I've just fitted a new front fork to my PX200 and have put the rest of the front end back together but I have a problem with the front drum brake actuating mechanism.

When I tighten up the actuating arm onto the cam shaft it makes the actuating arm stiff to operate and prevents it from returning fully. If I pull the actuating arm back it will move an extra cm or so. When the actuating arm nut is released along with the cam supporting bush/bracket bolt the brake is fine but wonder if there is a correct way to set up the brake.

Also, I replaced all the bearings in the hub/wheel but it is not exactly very freewheeling. is this because the bearings are all new?

Cheers.

[wack 63]

The hub should spin freely so either the shoes are binding ,the speedo drive is damaged or you damaged the bearings fitting them. Did you grease them well? .The brake cam /lever can be tricky to get right ,have a look here to make sure all the parts are there http://www.vespaspares.co.uk/spares/epc ... EVER&uID=0 .If so grease the cam etc then lock the arm to the cam then tighten the plate after the shoes have centralised.Make sure the shoe pivots are lightly greased and the shoes open and close freely.

[phil mcglassup]

Thanks for the reply...I'll give it a go.

I recently bought a HBOL for the PX but it lacks detail, it is the worst HBOL ever printed !!

[goldeneye]

i can be just a matter of grease in the appropriate places, and cleaning excess paint off bits, and make sure your brake return spring is in good order (i fit PX brake springs to lammy drums front and rear, they give a better "snap" back at the lever) make sure the brake shoes are filed down as well.

[phil mcglassup]

I cleaned and greased it well. I also had to reprofile (bend) the cam-shaft supporting bracket as it was at the wrong angle and nipped the camshaft when it was tightened. The actuating arm still does not return fully but it is good enough.

The scoot handles so much better with the new fork but the front brake is absolutely useless even with new shoes fitted.
Is there anything else I can do? The rear drum is excellent!

Thanks for all the replies so far!!

[goldeneye]

i use really rough emery cloth on the hub surface, file down the shoes so they are even all round, and cut slots at 45 degrees in the surface of the shoes to get rid of dust/water etc. while it wont be as good as a disc, i can get a drum pretty good, both lammy and vespa. if its got a two part front brake cable, with the in -line switch, ditch that, and get a one piece cable, its less spongey.

[phil mcglassup]

Thanks...I'll look at getting a one piece cable as it is spongey, though I guess I'll have to put the original back on for MoT.

I'll give the shoes and drum a bit more attention too!!!

Cheers,
Phil.