Well, as some of you will know from having been at Donny recently and last year at Snett I have had issues with the R1's brakes both times. Problem doesn't occur on the road, only the track.
Problem manifests itself as spongey brakes after a few laps which is what first happened at Snett, as the brakes cooled down the lever went harder so obviously we bled all new fluid through it but to no avail.
The bike sat for a fair period after Snett last year bar a few rideouts but in that time I had enough time to drain and refill the fluid as well as pumping out the pistons and cleaning them up as much as possible as I didn't and still don't have the special Yamaha hex tool for undoing the back of the calipers to take them out completely.
Before Donny this year I changed the pads in case they were the issue so they were changed for Brembo pads and all seemed fine on the road but I managed to get the problem to occur on the road in the hotter weather we had so I began to do more bleeding and passing fluid through. The odd thing was I managed to get ALOT of air out of the system despite returning to it on multiple days and bleeding it from both calipers and the MC as well.
At Donny the problem reared its head yet again but this time even worse, after every session there was a fine mist of brake fluid on the inside of the screen and signs of fluid leak from the rubber hose that connects the reservoir to the MC, at the reservoir end which is very odd as the pipe is tight and secure and the fluid would have had to be travelling UP into the reservoir to leak under pressure from that joint.
Each session I managed to get air out of the brakes and passed even more fluid through it, even ending up using DOT5.1 to get rid of any doubt that the brakes were, for some reason getting too hot.
One thing I did notice is that sometimes on track, the brakes went from spongey, to hard, then back to spongey and I also noticed that after each session, even though I'd pushed the rubber diaphragm up into itself, it appeared to have been "sucked" down into the fluid.
So, several theories depending on who you speak to, the bike has Titax after market levers which have been suggested as the problem although I am 99.9% confident the lever isn't pressing the brakes on all the time.
Also it's been suggested the MC has a dodgy seal.
Calipers are the other thing, although I pumped them right out and cleaned them as best I could I ran out of time for a full strip so despite the fact all the pistons move freely by hand, maybe one of them is being "banged" in sharply causing the normally low pressure hose from the reservoir to become under pressure and squirt out fluid.
Lots of theories, nothing concrete. So, plans are afoot to fix it.
I have ordered a standard brake lever from a local Yamaha dealer as well as a MC rebuild kit so going to do that, bike already has HEL braided lines on but I will also be attempting to rebuild the calipers too, which should be fun as they are monobloc so getting the back 3 pistons out should be "fun".
Limited number of possibilities but it's a frickin nightmare considering on the road it's generally fine and the bikes only done 7500miles!
Watch this space...
Quotethere was a fine mist of brake fluid on the inside of the screen and signs of fluid leak from the rubber hose that connects the reservoir to the MC, at the reservoir end which is very odd as the pipe is tight and secure and the fluid would have had to be travelling UP into the reservoir to leak under pressure from that joint.
this would have been enough for me to replace anything around that area that could have been causing this
the hose you speak of and possibly MC too
a tiny hole/leak that under track day temps is allowing fluid out, and air in too?
Quote from: komp on August 22, 2013, 11:36:33 AM
Quotethere was a fine mist of brake fluid on the inside of the screen and signs of fluid leak from the rubber hose that connects the reservoir to the MC, at the reservoir end which is very odd as the pipe is tight and secure and the fluid would have had to be travelling UP into the reservoir to leak under pressure from that joint.
this would have been enough for me to replace anything around that area that could have been causing this
the hose you speak of and possibly MC too
a tiny hole/leak that under track day temps is allowing fluid out, and air in too?
Who knows dude, there are no visible signs of holes or anything not tightened etc. The misting is definitely coming from the joint where the rubber hose connects to the reservoir but that "should" be so low pressure that it's not enough to every leak (unless it was loose).
The fact the diaphragm is getting sucked down so badly yet very little fluid loss, to me, suggests a sudden need for fluid to be pumped down to the MC and then back up again, hence that joint being a weak spot. But that's at best a theory.
A 2nd hand MC on Fleabay is about £150 and from an unknown origin so I loathe to replace that just yet.
You'll get a new aftermarket m/c for a bit more than £150:
http://www.bikersdiscountstore.co.uk/accossato-brake-clutch-cylinders-calipers-accessories/accossato/accossato-19-x-18-radial-master-cylinder-fixed-lever-pd-109.php (http://www.bikersdiscountstore.co.uk/accossato-brake-clutch-cylinders-calipers-accessories/accossato/accossato-19-x-18-radial-master-cylinder-fixed-lever-pd-109.php)
Cheers dude, it needs to have a brake light switch sadly as there is no room for a brake light banjo bolt sadly, it's a proper tight fit as it is and almost fouls the throttle cables
have you replaced the copper sealing washers on the banjo joint, if not that would be my next item but to be honest with the issues you have had I would have the whole system apart on the bench to check everything thoroughly, saying "Who knows dude, there are no visible signs of holes or anything not tightened etc." where brakes are concerned isn't good enough.
Get the whole system off and double check every seal and hose, stick braided lines on while you are at it.
brembo M/C it.
JD.
Quote from: Green_Ninja on August 22, 2013, 01:14:57 PM
saying "Who knows dude, there are no visible signs of holes or anything not tightened etc." where brakes are concerned isn't good enough.
I'm well aware of that, hence this thread.....
Quote from: Green_Ninja on August 22, 2013, 01:14:57 PM
Get the whole system off and double check every seal and hose, stick braided lines on while you are at it.
I wouldn't be bothering with all this if I was going to check everything......
And as I said above it has HEL lines already.
Peej, I stripped my new monoblocks right down when I received them (they are Tokico 4 pots, not the 6 pots like the Yam)
Easy enough job to do, but I was using an air compressor, and not fluid. What you do is place a brake pad against the pistons you don't want out, then jam a spanner in between the pad and the opposite wall of the caliper, making sure you're not restricting a piston, then pump the caliper until the 'free' pistons move out, then keep pumping until they pop out of the seals, by this time there should be enough of any piston to grab if it still being held in the seal. Remove all from that side, inspect the seals, clean pistons and replace. To do the other side, simply repeat but swap over the pad.
Quote from: Neil on August 22, 2013, 04:41:05 PM
Peej, I stripped my new monoblocks right down when I received them (they are Tokico 4 pots, not the 6 pots like the Yam)
Easy enough job to do, but I was using an air compressor, and not fluid. What you do is place a brake pad against the pistons you don't want out, then jam a spanner in between the pad and the opposite wall of the caliper, making sure you're not restricting a piston, then pump the caliper until the 'free' pistons move out, then keep pumping until they pop out of the seals, by this time there should be enough of any piston to grab if it still being held in the seal. Remove all from that side, inspect the seals, clean pistons and replace. To do the other side, simply repeat but swap over the pad.
Thanks Neil! Only just spotted this!
The rebuild of the mastercylinder has begun.
Rebuild kit purchased from Yamaha plus new copper washers :
(http://www.pjitsolutions.co.uk/albums/odds/mcrebuild1.jpg)
Old MC off :
(http://www.pjitsolutions.co.uk/albums/odds/mcrebuild2.jpg)
Pulled off the rubber cap/plastic outer plunger to find :
(http://www.pjitsolutions.co.uk/albums/odds/mcrebuild3.jpg)
Hmmm...... MC has now been rebuilt using new parts, refitted and pressure returned to the system. Now to bleed the fooker thoroughly...
did it fix it Peej?
Quote from: Millhouse on August 29, 2013, 01:50:37 PM
did it fix it Peej?
Well, the liquid behind the rubber end cap I am fairly sure was fluid, soaked it up onto some tissue and let it dry :
(http://www.pjitsolutions.co.uk/albums/odds/mcrebuild4.jpg)
Lever definitely has more of a solid feel but it's hard to say without giving it some proper shit which is hard on the roads round here. Its felt fine for the last 3 days going to and from work but I won't know for sure until I get it back on track.
To be fair, I can't see how it could be anything else!
snett on the 10th then? ;)
http://www.nolimitstrackdays.com/index.php/book-a-trackday/uk-trackdays/snetterton-300-10th-september-2013-detail
Hmmmm tempted!
*subliminal* do it *subliminal*
*bloody obvious*
GET IT BOOKED!!!
*obvious*
We have two family rooms booked at Barton Mills on the 9th if you need some floor space Paul
:moto: :moto: :moto: :moto: :moto: :moto: :moto: :moto:
and Lewis will give you a reacharound.
Has the poof booked it yet ? I'll set the friggin hounds on him next week in London if not ...........
Waiting for my boss to approve the annual leave you bunch of fuckers!
:moto:
(http://www.pjitsolutions.co.uk/albums/odds/snettorder.jpg)
:moto:
Trying to convince beer-chucker to join us but so far a lift, loan if my bike and a reach around from Lewis are not enough to swing it.
My reacharounds are only for you Dom and I shall be using a handful of glass... :kiss:
Quote from: LewisBeGoog on August 31, 2013, 11:24:36 PM
My reacharounds are only for you Dom and I shall be using a handful of glass... :kiss:
:rofl: