Bleeding brakes

[Knowledge]

This is one of my most detested jobs. Any tips?

I have vacuum pumps and big syringes. Fill from bottom or fill from top?

[drivera]

Bottom , but make sure you put plenty of cloths under the headset to catch spills from the master cylinder otherwise the paintwork will bubble !!

[Knowledge]

Thanks, but I didn't think this was as much of a problem with DOT4 fluid, when compared with DOT3 ???

[Dazts1]

Fully synthetic dot 5 no issue with paint what so ever. I've just tried from master to slave it didn't go well. I pulled the piston out of my inboard caliper as far as I dared and filled it up with fluid. The hose still had fluid in it just also had air as well. I then connected the hose and pushed the piston back. This almost bleed the system. I've also fitted a radial master cylinder which also has a bleeder at the top. This definitely helps a lot. My trip to York showed a drop in fluid but the brake still worked. I topped up yesterday once home and all seems fine. But I'll keep my eye on it.

Good look

[jonashford]

inject from the bottom to the top you shud see the fluid fill the master cylinder then a few pumps of the lever shud do the trick about a 10 minute job, if not tie wrap the lever to the grip overnight

[CHRIS in MARGATE]

Never had a problem filling from top and taking bleed nipple out as far as it will go or out altogether
When fluid starts to run just screw it back and carry on conventionally. Don't use aerated fluid for a while to replenish master cylinder.

[AlG]

Just done this with an old school inboard hydraulic conversion. I eventually found the best way was to take the wheel out, lay it on its side, then use a syringe to fill from slave up to master. I also did the rubber band on the lever overnight and in the morning it was perfect.

AlG

[Knowledge]

Ok, I have order a new syringe and I will try from the bottom to the top.

I haven't heard of the rubber band trick, so may resort to that if necessary.

Thanks, but keep them coming.

[missing lynx]

I just open the bleed valve with a tube on it in a jar of brake fluid and slowly pump the leaver while filling the top it's easier if you've got some one to watch for bubbles in the tube can take a little time but never had a problem with this method

[Knowledge]

Well, in the end, I did just that ^

I tried to fill from the bottom, but it wouldn't happen, so I fille dfeom the top, pumped and it was soon done. About 10-15mins. Probably the quickest brake bleed I have ever done.

I rode the scooter today for the first time today, and it has huge potential.

[Storkfoot]

Apologies, it's a bit late but, years ago, I picked up a great tip from this forum. That was, take the lever off and pump the piston with the end of a pencil. You get the piston to move further.

If it's an inboard hydraulic, lying the wheel on its side is a great help too. This may work on an external set up too but I haven't had one of those for several years.

[coaster]

The last one I did I used the gravity method with pumping and it worked fine. But using the syringe to 'suck' the fluid through is also worth trying if you get air locks.

[Toddy]

Undo bleed nipple slightly , Syringe , Tube and push up from the bottom , pushes all the air upwards into the MC , 2 minute job

[Dazts1]

I must be doing things wrong. The quickest brake bleed I've ever done is with a radial Brembo master cylinder it did really take 5 mins.
I've just put a cheap copy of this onto my road scoot adelin version and messed on for a week.

[gaz_powell]

got one to do next week !

[Dazts1]

You've got an adelin to bleed Gaz ?

[gaz_powell]

No Daz, just an inboard hydraulic

[Scooterlam]

My in-board hydrolic lost its nipple. Ooeer.
Loosen bottom Bangor fill from top.tighten Bango when it weeps.
Cable tie the lever to the grip and in the morning it's done.