Breva 750 Rear Brake Master Cylinder |
Post Reply |
Author | |
Eibar-Jet200
Falcone Joined: 06 Sep 2016 Location: West Lothian Status: Offline Points: 55 |
Post Options
Thanks(0)
Posted: 27 Aug 2017 at 19:08 |
Hi all,
Ok, I have tried for ages to bleed the back brake after a caliper rebuild but with no real avail. I have replaced the black hose underneath but it just refuses to pump any amounts of liquid through. I have tried pressure feeding from the bottom as I had no top that fitted to do it from the top. So I am guessing it may be the Master cylinder. Is there any "better" ones than the standard? Or do I need to buy a replacement master? Thanks for any advice. John |
|
Thanks
John |
|
telegraphroad
Senior Member Joined: 21 May 2014 Location: M11 J8 Status: Offline Points: 204 |
Post Options
Thanks(0)
|
I don't know if the rear m/c is the same/similar to the one on the v50 but if it is then there is a tiny pinhole in the top of the cylinder bore which acts as a fluid transfer port from one side of the piston to the other. If the rear brake is refusing to bleed then it could be that the pinhole needs clearing. I battled with a difficult rear brake for a while until I did that. IIRC there are actually two holes in the cylinder bore and the smaller one is really difficult to see even when you know where to look. You will need to shine something down there to see it from the inside. It is accessible from the outside if you remove the inlet elbow on the top of the m/c. After I cleared mine the brake bled through first try and was firmer than it has ever been.
|
|
V50 Monza
VFR 800FI Herts / Essex border |
|
Eibar-Jet200
Falcone Joined: 06 Sep 2016 Location: West Lothian Status: Offline Points: 55 |
Post Options
Thanks(0)
|
Thanks for that. I will have a look tomorrow.John
|
|
Thanks
John |
|
Eibar-Jet200
Falcone Joined: 06 Sep 2016 Location: West Lothian Status: Offline Points: 55 |
Post Options
Thanks(0)
|
Stripped it and it was full of gunk under the rubber bung on top. I could not blow through it even when pumping the piston. Nightmare!
So a new one from Gutsibits ordered but 7-10 days delay. Aaaaaaaahhhhhh!!!!! Lambretta it is for another 2 weeks! John |
|
Thanks
John |
|
Mike H
Senior Member Joined: 21 May 2014 Location: East Anglia Status: Offline Points: 8733 |
Post Options
Thanks(0)
|
Sounds familiar, had this on my R80's front brake m/c, wouldn't bleed (albeit perversely the brake worked prior to being disturbed - don't they always?), stripped the m/c, full of cack and the cylinder walls corroded. Become scrap.
|
|
"Chicken nuggets don't dance on a Tuesday."
|
|
Roadrunner
Senior Member Joined: 06 Jun 2014 Location: East Yorkshire Status: Offline Points: 411 |
Post Options
Thanks(0)
|
I had the same problem with my lil Breva. You can get new master cylinder from ebay as soon as you fit the new cylinder it will bleed straight away what joy
|
|
telegraphroad
Senior Member Joined: 21 May 2014 Location: M11 J8 Status: Offline Points: 204 |
Post Options
Thanks(0)
|
Glad you got it sorted.
|
|
V50 Monza
VFR 800FI Herts / Essex border |
|
Eibar-Jet200
Falcone Joined: 06 Sep 2016 Location: West Lothian Status: Offline Points: 55 |
Post Options
Thanks(0)
|
Thanks.
I need to spend tlc on the Lambretta. Been about 4000 miles now. 2 more weeks little one......... John |
|
Thanks
John |
|
Post Reply | |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |