Hi all. My multistrada has been off the road for 12 months because of a crash and now that I am finally ready to start work on it I have a problem with the front brakes. As the bike hadn't been moved for a while the front brakes needed a coat of looking at and new pads fitted. I took the callipers off the bike to give them a check over and they weren't as bad as I expected. All the pistons moved freely with just hand pressure. I fitted new pads, put them back on the bike and bled the system. The pressure at the lever was solid and all seemed to be ok. (pat on the back for me). I rode the bike up the street to try them and every time I pulled the lever the brakes bound on more and more until they were practically locked on. Thinking I had made a schoolboy error I stripped them again and went through the same process only to get the same result. It is as if the fluid is staying under pressure after I have pulled the brake lever and isn't returning to the reservoir. I am taking it for a service next week and I would like to be able to ride it there and not have to get it trailered. Please help me. cheers Gary.
You could start by giving us a clue what brakes you have. ABS or non-ABS? 2010-14 type or 2015-17 type? Hill start function or not? Does this problem manifest while you are static in the garage? Or does it only show while you are riding along?
Has your bike got a small screw on the lever for adjusting free play?It sounds like this may have been wound in a touch,so that basically your brakes are slightly on all the time.They need a couple of mill free play before the lever actually presses on the mastercylinder.
Hi.Cheers Keith. the brake lever adjuster is wound right out so I don't think that is the problem. Sorry about the lack of info Pete but I was in the zone and forgot that there are other multistradas out there. It is a 2013 twin spark model with ABS and no hill start function. On further investigation I have realised that it only does this when the engine is running so I am leaning towards an ABS pump problem. Cheers Gary
So are you saying that with the engine not running (ignition on) you can apply the front brake as many times as you like and it continues to release normally? But that once the engine is running (bike stationary) if you apply the front brake repeatedly it sticks on and won't free? If so, then it surely must be an ABS unit fault - and a very odd one at that.
That's about the size of it Pete. I parked on a hill and pumped the front brake with the engine running until it bound on (only three or four times) switched off the engine and after about five minutes it started creeping down the hill and then gradually freed its self off. Baffling Looks like its a job for the mechanic next week.££££ ouch. cheers for your input. Gary
From what you say, the problem cannot be caused by overheating, nor by the rotation of the disc, nor by the front wheel ABS system pickup. The ABS unit (box under the seat with four pipes leading to it) must be the problem I think. Unless anybody has a better idea ... ?
I had exactly the same problem with a Fireblade a few years ago. However it did not have ABS brakes. It turned out that there was a tiny airlock in the callipers that kept binding the front brakes. A decent bleeding sorted it out.
I am still thinking it is the ABS unit which is at fault, but although the lever felt good after I bled them I will try to bleed them again to rule that out an air lock. Can anyone tell me which order to bleed the system in as I am not sure when to bleed the master cylinder. Cheers.
Couple of thoughts , where you say bike was off road because of a crash , was any damage done to brake levers ...snapped off maybe ? Is there air space left in the front resvoir ...it's not completely full and the relief hole in the cap blocked off for some reason . Where you say if you pump the brake whilst engine running till it binds , then switch off and after 5 mins the brakes start to realease , ....... so I assume if you left the engine running but left it 5 mins without touching the lever ,in this case the brakes still stay binding . As a rule abs valve blocks are pretty reliable , even when engine running and stationary the inlet and outlet shuttle valves are at rest , they only operate when on the road and wheels lock and the pump kicks in to modulate the pressure . Has the braking system been left dry for a period of time ? If you pump the lever and get the brakes to bind whilst engine running , then crack off the bleed nipple at the master cylinder do the brakes immediately release , does the fluid squirt out with some force ?
Hi lee. The only damage to the bike was plastics ,headlight and brackets. Nothing at all to anything mechanical. After the crash I rode the bike about 3 miles home and the brake issue didn't happen. I am assuming that the problem has happened while the bike has been standing unused. The reservoir fluid is on the full mark when the rubber insert is in place and the cap is screwed on. When the brakes have bound on and then the engine is switched off the brakes start to release but it takes about 30 mins for them to fully release and return to normal. If I leave the engine running when they are bound on, the brakes get so hard that there is no travel on the lever at all. I haven't tried bleeding the system when it is pressurised, and it has never been left with no fluid in the system. I cant understand what could cause the system to pressurise to that extent. Cheers Gary.
Definately non of the aero quip hoses around the frontal area have been pinched with fairing brackets and so on , just thinking they could allow pressure to the calipers but not return because of a restriction . So get the brakes to bind and then crack off front master cylinder bleed nipple see if they release immediately , if they don't realease you would need to crack off the in going pipe to the valve block , if no release crack off the out going pipe on the valve block that goes to the calipers . Thing is while your doing this the pressure will be releasing a little whilst your doing the work so you may have to pump the brake up after each step so not to confuse the diagnostic pathway . If you crack off the outgoing pipe from valve block to calipers and the brakes are still on and cracking off the caliper bleed nipples lets the bind off the line from valve block to calipers must be pinched or restricted . If you don't find anything from these tests ,next test would be to pull the multiplug off the valve block so the motor which creates the pressure cannot run. I'm not sure on the multi but on cars often the car will not start with the abs modulator plug off due to the can network not being happy to see no abs on the network but one step at a time , let us know how you get on . It sounds a lot but with seat out of the way 2/3 mins to do this diag .
There's a thought. Although if an abs sensor fails it will let you ride, what if something else more critical in that system fails: does the multi failsafe the brakes on? Can't imagine it does??!!
