What do do with those bl*%dy brakes?

paso750 · **Posted:** Wed Mar 23, 2011 7:24 pm

here you go. I disassembled two broken pumps so ignore the way I did it

The condition of your cylnder is much better than these two.
The O ring sits on the outer end of the cylinder. Then comes the white plastic ring with its wide side towards the O ring. Pulled over the plastic ring is the dust seal and then comes the circlip.
Now you know what do do

G.

ducinthebay · **Posted:** Wed Mar 23, 2011 8:22 pm

Another technique that has worked from time to time is to pull the lever all the way against the bar, and tie it there with a rope or twine for a day or two. then untie it, let it equalized for a few minutes, and try it from there. It sometimes gets the stubborn bubble that is in the master cylinder. Sometimes.

Cheers,

PasoRoo · **Posted:** Thu Mar 24, 2011 11:54 am

Thanks for the pictures G! That should be a good guide for putting this thing back together. I won't have time until the weekend but I'll let you know how I get on. :truck:

Thanks,

Mike

streetsurfer · **Posted:** Thu Mar 24, 2011 2:31 pm

IIRC, some of the bleeding trouble comes from the angle of the bars and master cylinder. Removing it from the triple crown and setting it so there was no high spot to trap air helped my bleeding. Mityvac pump as well.

higgy · **Posted:** Thu Mar 24, 2011 4:21 pm

acrobatics? multiply days to bleed ?

Yesterday I couldn't spell Technician
Today I R one

Get setup to r-e-v-e-r-s-e b-l-e-e-d
you will not regret it and it works easily and the first time on every hydralic system ever made.
no more :banghead:

BARONROJO · **Posted:** Sun Mar 27, 2011 8:13 am

A very easy tecnique that works for bleeding the MC needs no tools at all:

1.- Turn the handebar full left.
2.- Tilt the bike leftwards as much as you can (Trust on your force or a helping friend)
3.- Pump repeatedly.

The theroy is very simple: In this position, the MC is completely tilted the right side and therefore, bubbles can scape into the MC's reservoir.

Same applies to clutch (Opposite side, of course)

PasoRoo · **Posted:** Mon Mar 28, 2011 10:57 am

Thanks for all the tips guys!

On the bleeding: I have bought a banjo bolt with a bleed valve from ProBolt as shown below.

banjo_w_bleed.jpg [ 29.9 KiB | Viewed 4110 times ]
This is the best $17.50 I have spent for some time. It works very well and saves me having to lean the bike, tilt the handlebars or any of the other tricks. Because of how the master cylinder sits on the handle bars it it ths highest point of the system. :thumbup:

However, to update you on the sorry saga:

Assembled the master cylinder using G's pictures and the Brembo instruction sheet and filled it up with brake fluid. Started bleeding and had lots of air bubbles coming up. Beautiful!

Then: fluid coming from the side of the lever. Aaaaargh! :banghead:

Taking the cylinder apart (I can do this in one minute flat now :lol:

) I realised there is a space between the circlip and the plastic ring if I put the parts in according to the Brembo instructions. This allows the rubber ring and the plastic one to move and, I'm assuming, fluid to get through.

However, from G's pictures, and taking the cylinder apart the first time, it seems the rubber boot sits under the circlip. This would prevent the other rings from moving and seal better. :idea:

So we'll give this another go and put it together again. After that I'm going to have a lot of beer and a little lie down.

Cheers,

Mike

paso750 · **Posted:** Mon Mar 28, 2011 11:11 am

blazing928 · **Posted:** Mon Mar 28, 2011 1:05 pm

Mike
sorry to hear your problems.
i just replaced the master cylinder, as a matter of old age & rust, recently along with braided lines from Racebrakes in Melbourne as my front line started to weep.
[They make ADR approved lines, has a plastic bit that must stop the line chaffing to get ADR approval]
Anyway I too had the same issues as you.
In the end I put the cover on, to stop the fountain and just pumped the lever fast and hard.
All of a sudden I got some resistance in the lever and after that it was easy to finish the job.
I did get a fine stream of bubbles coming out of the master cylinder when I just flicked the leaver slightly.

I am sure you are monumentaly frustrated, so I hope this may help, you are lucky you have Jeff there to help!!

paso750 · **Posted:** Mon Apr 25, 2011 11:30 am

any news on this ?

G.

PasoRoo · **Posted:** Sat Apr 30, 2011 10:59 am

Hi G,

Sorry for the late reply, this week has been a bit crazy. You asked what happened with the brakes. Well, this is what happened:

DSC_05780001.JPG [144.32 KiB]
Downloaded 309 times
.

A 916 master cylinder from Bevel Heaven, remote reservoir from Ian Gowanloch, rubber grommets from a local shop and a home made bracket that I'm rather proud of...

I did get the original master cylinder to stop leaking and build up some pressure, but it was still really soft. I decided to stop messing about and go for the new parts. I have to admit it did feel a little bit like cheating to not get the original part working after an overhaul, but I decided that it was more important that I could ride the bike.

As a matter of fact, the morning after I mounted and bled the brakes the bike was at the AutoItalia event here in Canberra. Lots of Italian cars and a good turnout of Ducatis, Guzzis and other Italian bikes.

DSC_05700001.JPG [232.02 KiB]
Downloaded 309 times

It sure is great to have the bike back on the road. Next item to solve: running on one cylinder directly after startup, after which it kicks in before I reach the end of the street :lol:

Cheers,

Mike

Maico88 · **Posted:** Sat Apr 30, 2011 12:11 pm

A chart of brake master to caliper ratios can be found here. http://www.vintagebrake.com/mastercylinder.htm

higgy · **Posted:** Sat Apr 30, 2011 12:36 pm

What do do with those bl*%dy brakes?

Who is online