Pressure Bleeder

Yep, new Copper Banjo Washers on.... both the Caliper and Master Cylinder ends.

with a normal tube bleeder (where you pump the lever) that works, fluid runs from the Cylinder fine, through the hose fine, and out of the bleed nipple fine, a whole bottles ran through easily but still didnt help with the braking
(no resistance in the lever, not enough pressure to stop the disc moving)

this new vacuum bleeder, doesnt bring hardly any fluid from the nipple, just little trickles now and then,
I cant see there being a problem with the Master Cylinder end as it works perfectly fine with the other bleeder (which I cant use now as its blocked) tried doing it without the end nipple fixing incase that was blocking the actual hole... but the pipe that came with it is too big to fit onto the bleed nipple valve, if you know what I mean.



(other Bleeder I got it a tube with a part on the end with a little ball inside which stops air going back up, but it was left outside in brake fluid and rain and its blocked............)

 

Been giving this some thought. Are the master cylinder seals the right way around, if they are on the wrong way around it will push the fluid down to the calliper but it won't be able to put any pressure on. Also if you try to suck to fluid through woth the pump the seal will not let it past.

 

Well they're Aerox Master Cylinders,
I bled the front one with the Bleeder Pipe which worked fine,
im not sure how the Aerox ones are made,
they were from a working Aerox Bike and weren't messed with in any way so they're standard Aerox ones....

 

wouldnt this work if I tie the brake lever down and then use the vacuum pump abit... then untie the lever and keep doing that...

 

No, if you pull the lever the piston will come forward and the vacuum pump won't be able to pull the fluid from the reservoir.
Are you sure that the master cylinder is working properly?

 

I would connect my front brake line to the rear brake master cylinder and see if you can bleed it, if it works then you will know that it is not the master cylinder and it must be either the pipe or calliper.

 

Yep, both front and back came from a working bike, theres been 3 Master Cylinders on this Bike now...

1) Original Aprilia ones, which were working but were too bulky
2) Brand new Universal rear one, which worked... but then I took the Banjo Bolt out of the Caliper and since then stopped working...
3) Tried the original again as I knew that worked but again wouldnt bleed...
4) Aerox ones on now, both from a running Bike, front bled easily, but still a problem with the back.

All started when I removed the Banjo Bolt from the rear Caliper to spray it, after it dried I put it all back on, rear brake wouldnt work/bleed, took the Caliper apart, checked Pistons and Seals, scraped off any dry paint around it all, Pistons come out easily when the Levers pulled so I dont think its the Caliper.... and again 3 Master Cylinders cant be broke.... so must be the Pipe.

 

If the pipe is damaged it will leak fluid, an unsealed banjo washer can at times suck air but not leak fluid . Try forcing fluid from the calliper back along the line to the master cylinder.
You can do this by taking out the pads and apply the brake gently to force the piston out as far as it can without popping off. Then push the piston back in by hand and this will back feed the fluid pushing out any air trapped at the top of the pipe. You could also try using the pressure bleeder to force fluid via a tube connected to the bleed nipple.

 

Well I have done that before with the Pistons, took the Pads out, pumped the lever until the Pistons came out and nearly touching, then pushed them back in, so should I keep doing this and checking for bubbles in the Cylinder...?

 

That's a good suggestion if you've got really long arms or someone to look in the reservoir while you push the piston in..

 

Right, they are working A LITTLE, and I mean a little, tested it out on the road and it doesnt stop the wheel but when slowing down it does help come to a stop...

I pushed the Pistons in, and then let them come out, and then couldnt get them back in so undid the nipple valve to let some fluid out (and to get the pistons back in), but yeah they're working a little, so must be air in the Caliper...?

 

Do you still have the original Aprilia brake cylinder Jo?

 

Cancel that last one, just re-read your earlier post

 

As Mr Bizzle says, swap the calipers over just to see if the caliper bleeds ok, pressurizes normally and works properly. If it does that means the fault is either in the brake pipe or master cylinder. Got to be worth a try after all you've tried so far.

 

Is the calliper standard as I noticed from the video that the lettering (Aprilia) was upside down. Also if the calliper piston is larger than an Aerox one, the master cylinder may be too small to push sufficient fluid without pumping the lever.

 

Calliper is standard yes....
my Dads down on Monday (used to have a Bike) so going to take it over to my Nans and spend a few hours on it, but yeah the Brake is working to a point, better than it was before, when on the stand and I rev it for the wheel to turn... and pull the brake, it does stop the wheel, but when im actually out on it and going a little faster, it doesnt quite stop it as good, only at a low speed, so yeah its getting there, there was some squishy sounds in the Calliper though when putting the Pistons back in (air..?) so will do what I did a few more times on Monday and see how it goes from there, really dont want to be taking things off/apart again so if just pumping the lever so the pistons come out and pushing them back in has helped a little so far then hopefully a few more goes will sort it *fingers crossed*

have just given it a wash aswell and sprayed some anti-corrosive dry lube in parts, what with the weather now I dont want everything going rusty!! also got some Profi Fuel-Max (which is like Redex?) as I dont know how the 'inside' of the Bike is, not sure if the previous owner used anything like this or actually cleaned inside the Carb etc, being a 2008 Bike its better to be safe, so yeah will use the Profi to clean the pipes/carb on Monday aswell...

 

Have you trued pumping the brake to see if the pressure increases?

 

Yep tried that, it is getting there though, pushing the Pistons in worked... and with the squishy sound which was obviously air in the Calliper, so i'll do that a few more times on Monday.

The Bike you sold to someone in Ely, was that the one in your Avatar? dont really see Aerox Bikes around here but seen one the other night passing me but the Handlebar casing was White I think :-/ or the top bit of it.

 

My old Aerox is in Rossi rep colours now, the old man resprayed it before I sold it.

 

Yeah thats the one, went past me... nice Bike