Bleeding brakes

[Papasloan]

Just put dual disc brakes on the Stone. I picked up a right side rotor from an ev and the 2 calipers. I used the rt side brake hose from the ev and the left hose from the stone and a master cyl for a Ducati .
What I have read bleeding brakes on these bikes is a pain.
Well I decided to use 2 things to help me bleed the system. a one man brake bleeder with a small bottle attached to a magnet and gravity.
First thing I did was put teflon tape on the bleeder screw threads to keep from sucking air when using the bleeder. Then after bolting everything together and putting some brake fluid in I kept squeezing the brake lever about half way or less to work the air bubbles out of the master cyl. Then let it sit for 10 or 15 min. and squeeze it some more to work out the air bubbles. Once the bubbles stop then you can use the bleeder. Hook up the bleeder and open the bleeder screw. The fluid will start to flow in to the bottle. make sure you keep the master cyl full or you will have more air bubbles to work out. Close the bleeder screw and bleed in the time honored mode of pulling the lever and open the bleeder screw to push air out of the caliper. Do this till no more air comes out. All the time making sure not to let the master cyl run dry. do this on both calipers.
Most all of the air will work its way to the master cyl. Bubbles rise in fluid, just keep pumping the brake lever to work the bubbles out. With out the cover on fluid will spit so cover the paint and pump slow.
I had to reroute the right brake hose after the bleeding was done. I was able to work the air back in to the master cyl by simply pumping it. I did not haqve to bleed at the caliper.
All in all bleeding was quick and easy. I didnt try to push the air out the bottom I worked it out the master cyl.
This procedure should work on any bike. Just dont be in a hurry. let the bubbles work their way up the brake hose.

 

[Warwick in NZ]

Hi, Just wondering the master cyclinder bore size, usually stamped on top, above the switch at the front thanks, Warwick :cheer:

 

[Holt]

I'm using compressed air and a bleeder attachment for bleeding the brakes. It's a five minutes job, and also a one-man job.

 

[kiwi dave]

Holt wrote:

I'm using compressed air and a bleeder attachment for bleeding the brakes. It's a five minutes job, and also a one-man job.

My reservation about using compressed air is the possibility that brake fluid might get to places where it is not desired.

I use a vacuum type bleeder which "sucks" the fluid through. It's a manual hand pump (squeeze to operate), I've been thinking about attaching a small 15 psi vacuum pump, but haven't found a suitable candidate yet.

 

[Holt]

kiwi dave wrote:

Holt wrote:

I'm using compressed air and a bleeder attachment for bleeding the brakes. It's a five minutes job, and also a one-man job.

My reservation about using compressed air is the possibility that brake fluid might get to places where it is not desired.

I use a vacuum type bleeder which "sucks" the fluid through. It's a manual hand pump (squeeze to operate), I've been thinking about attaching a small 15 psi vacuum pump, but haven't found a suitable candidate yet.

My compressor operated bleeder IS a vacuum bleeder. No spill, no hassle. Cheap too.
And you don't need a helluva compressor either.

 

[Morizzi]

I use a pressure bleed system. Its what I have so I use it.

I fill the master cylinder up, put on a cap that has an air nozzle on it and apply air pressure gently. It only needs a couple of psi. That's enough to push the fluid through but not enough to cause a mess. In fact its so low theres not enough pressure to seal the valve in the end of the hose so its constantly venting.

Works fine, no mess, one man operation. The vacuum system works well too by all accounts. I'm not saying what I do is better because it isn't. It works just as well though.

A little care is all it takes. I found screw on caps from jars or containers that fitted the reservoirs, put in a rubber seal and fitted the air nozzle.

The main advantage I can see of the vacuum system is it would work well for unusual shaped reservoir caps. My V65GT has one of those for the single front brake. That's easy to bleed manually anyway.

Just another way of doing it.

 

[Roblatt]

why not just stick one end of the hose in your mouth and blow, if not much pressure is needed?

 

[contractor20]

Blow and suck blow and suck blow and suck
Jeeeezuuzzzz you blokes wots with all this stuff with bleedin brakes !!!! put the bloody fluid in the top and pump til the new stuff comes out the bottom. THATS IT ....DONE end of story Christ it's not rocket science !!!

mutter mumble mumble pumps mumble vacuum mutter mutter .............15ps........mutter mumble

Kym

 

[Roblatt]

contractor20 wrote:

Blow and suck blow and suck blow and suck
Jeeeezuuzzzz you blokes wots with all this stuff with bleedin brakes !!!! put the bloody fluid in the top and pump til the new stuff comes out the bottom. THATS IT ....DONE end of story Christ it's not rocket science !!!

mutter mumble mumble pumps mumble vacuum mutter mutter .............15ps........mutter mumble

Kym

frustrated are we?

 

[Holt]

contractor20 wrote:

Blow and suck blow and suck blow and suck
Jeeeezuuzzzz you blokes wots with all this stuff with bleedin brakes !!!! put the bloody fluid in the top and pump til the new stuff comes out the bottom. THATS IT ....DONE end of story Christ it's not rocket science !!!

mutter mumble mumble pumps mumble vacuum mutter mutter .............15ps........mutter mumble

Kym

Ooh, you're right.
In principle.

But one man, container and brake pedal on the right side and the caliper and bleeding nipple on the left. Takes long arms.
Or the two disc system with the second disc connected with a hose from the first, a tiny little drop of air at the apex...

Well well well. Not rocket science.
But a hard pressed patience!!

 

[Christofero]

The new non-integrated bikes should be a dawdle to bleed - gravity alone should do it and produce the hardest pedal/lever.

The problem with using compressed air or vacuum is that you can move the fluid very quickly and cause cavitation which gives you a soft pedal. If you do use pressure/vacuum to do the initial bleed it is a good idea to gravity bleed out the air as a last step.

The old integrated system is another matter - it can be a real pig. The line that connects the front to the back brake is above the master cylinder and causes an airlock that can be difficult to overcome. So you can either reroute the line along the bottom rail and use a long piece of aeroquip for the front brake that you tie up at the headstock for normal use and bring down when you bleed the bike or you can use pressure/vacuum.

Another tip is to tap the brake cylinders with mallet to consolidate any air bubbles. Sometimes you have to remove the calipers and twist them around until the air consolidates at the bleed nipple.

I'd like to know what the factory did when they had to bleed up hundreds of them.

ChrisR

 

[GrahamNZ]

Holt

I've always managed to bleed bike brakes alone and without any special bleeding tools. Even fitting new hoses and new calipers has never been a problem but then I've never had a bike with other than a simple brake arrangement. Linked brakes are not my preference and I'm pleased that Guzzi didn't put them on their modern bikes.

Graham

 

[londonrob]

I miss my linked brakes!!!!!!
You could stamp on that brake pedal as hard as you liked, even in heavy rain, and still come to a stop in a straight line...

 

[guzzibob]

I'm with you london rob, very much like the linked brakes on my old Tonti's. Really wish my Norge had them. Norge front brakes are really good, but rear is totally wooden & impossible to modulate, would completely suck if not for ABS.

 

[RJVB]

You mean like either it works hardly more than the engine brake, or (if you stamp really hard) the ABS kicks in coz the wheel would block?
(think I'm due for new brake pads, approaching 30k km)

 

[Papasloan]

The master cyl I used is 16mm.
And it works F'n awesome. Had the chance to climb on it hard. Didnt slide the wheel but it was making funny noises. Yeehaw!

 

[Greg Field]

I use a big syringe to push fluid from the caliper to the master cylinder. As long as you are careful to let all the bubbles settle out of the fluid in the syringe before pushing it into the system, it works perfectly, and you get a hard lever the first time you pull it.

 

[RJVB]

That means you uncouple the brake line from the caliper I presume?

 

[Papasloan]

No he is pushing the fluid in to the bleeder screw instead of sucking the fluid through it or pushing it through the Master cyl. Just have to be careful to not overflow the master cyl.

 

[Holt]

GrahamNZ wrote:

Holt

I've always managed to bleed bike brakes alone and without any special bleeding tools. Even fitting new hoses and new calipers has never been a problem but then I've never had a bike with other than a simple brake arrangement. Linked brakes are not my preference and I'm pleased that Guzzi didn't put them on their modern bikes.

Graham

Ooh, I do believe you. So have I.
Just so much faster&easier using a comp-air bleeder. You'll do 2 bikes in 10 minutes for a complete change of fluids.

You stubborn old farts do as you do anyway, not trying to do anything but pursuate you. :laugh: