Seized front wheel on my Vespa PX 125..... help / advice

[sandymitchell76]

This question may have a very obvious answer but I am a total novice in terms of maintenance so am hoping to lean on the experience of others.

I was having a problem for a couple of months with my Vespa suddenly losing power early in the ride and mid ride; having googled the issue I was convinced by the advice I read that it was caused by minute rust particles in the fuel tank clogging things up...… a good rev seemed to do the job and I was able to carry on.

One of the other pieces of advice suggested the front brake may be binding..... well, at very low speed just before Christmas the front wheel locked on me and the bike and I took a tumble..... the front wheel is now seized up so I assume it was down to the brakes binding all along!

Here is the obvious bit...… does that seem correct?

If so, how easy is it to change the front brake pads and is there anyone in the Manchester area who would be willing to show me the ropes..... always keen to learn and happy to pay for the privilege.

Not quite sure of the accepted etiquette on the forum for this sort of thing but thought it was worth asking the question.

 

[Grimmripper]

Here is a video for changing brake pads. Personally I like to use a dab of thread lock when refitting caliper bolts (sometimes these have an allen key head)


Here is a text based version
www.scooterhelp.com/genmaintain/brake.pads.html

Make sure someone has not overfilled the brake master cylinder reservoir with brake fluid. This can lead to the front brake locking up also.

Cheers

MattO

[phattanglo]

When the scoot is on the stand are you able to spin the front wheel and if so does applying the brake stop it straight away.
Is the wheel able to be spun again easily after you release the brake lever?

[sandymitchell76]

Thanks very much for the responses.

@ phattanglo - the front wheel doesn't move at all now..... totally seized!

@ Grimmripper - thanks for the video, ill check it out...… would you say it is a relatively easy / basic maintenance job?

[mijapxman]

Out of interest, do you have a speedometer cable fitted? Bud.

Mij ☺

[ironsloth]

If you can't push the piston back in the caliper, you had probably better buy a new one. They are an absolute t**t to refurb and reseal, and use copper grease on the back of the pads when refitting. Reckon you can sort it for about £60. I would also check your disc, my guess is there's a lovely groove on your disc, would look at that too when the calipers off.

[phattanglo]

If the caliper is proper goosed then yes you would be looking at replacement.
The standard caliper is pretty simple and robust but as with most scooter calipers it is very vulnerable to road crap seizing it up.
You might as well have a go at a rebuild of your own as usually it's just down to a bloody good clean.
I use a method which is a bit basic but is straight forward for a home mechanic.
Take the front wheel off. Remove the caliper bolts and wiggle the caliper off the disc, if it's seized on it might need some gentle persuasion😁
Put a spanner or similar in the gap between the brake pads so you can pump out the pistons equally without them popping out
completely.
Give it all a good scrub with hot soapy water and then see if you can push the pistons back in.
If so repeat the pumping and washing process until the pistons push in fairly easily.
At this point I pump both pistons out to the point where they can be removed completely after the fluid is drained off.
I then drain off the brake fluid, dismantle the caliper and remove the pistons taking care not to scratch or mark the piston surfaces.
Don't be put off by this prospect as the caliper is very simple to rebuild.
Remove the four bolts holding the two halves of the caliper together ensuring you retain the small rubber o ring sandwiched between them.
Using a slim but blunt tool, wiggle out the two piston seals, if the internal surfaces of the seals are smooth and intact there is no reason why you can't re-use them.
At this point you should gently clean out the groove that the seal sits in and the seals themselves with the hot soapy water again taking care not to scratch the bores and when squeaky clean thoroughly dry everything as water and brake fluid are not a good combination.
My preference when putting the seals and pistons back in, is to use red brake grease which has proved to aid re-installation and seems to prolong service intervals, certainly it's been over 18 months since I last did mine and it's used daily throughout the year.
It's likely this should do the trick but if not it's only wasted an hour and it's a useful learned skill.
I always find it rewarding to be able to DIY and Vespas are a great candidate for home mechanics.
I hope this is of help to you.

[sandymitchell76]

Thanks for the advice everyone...…. I've not been thinking about it much for the last few weeks as it hasn't stopped raining (!) but am keen to have it up and running again for the spring so will get onto it. Thanks again.

[ironsloth]

Fit a knobbly back tyre (like what they used in the Dakar on the P200) and a ski on the front, that would be awesome..... 😎😁