Hi All,
Having a weird and scary issue the last few weeks with my 2006 Varadero 1000. As I've been descending passes in the alps, I loose pressure in the rear brake when I go to depress it. It usually takes a few pumps to build up enough pressure to use the rear brake again.
Dealer thought it was due to dirt in the lines, so they replaced the fluid. But started having the issue again yesterday in Austria. Wondering if it's a master brake cylinder - though thinking it's not possible as the lever isn't getting stuck in a different position.
Not leaking any fluid at this point, so I don't think it's a leak.
At some points it won't work at all - and at others, it's completely fine. Any ideas on what could be wrong here?
I had an earlier 80's Kawasaki years ago when I got it the front brakes when you pull the lever there was no brake I had to pump it probably 5 times thinking about it now knowing a little bit more it was dropping pressure slowly while I was breaking . the cure was a master cylinder rebuild kit although that was pre internet days so I got somebody else to fit it for me . these days if we really want to learn how to fix our bikes all the tutorials are there on youtube and what ever . good luck with it . sounds like your bike shop are a bit amateurish that they didn't cop it .a lot of them are only able t to replace consumables and some are not even great at that but don't tell them that or question their prices as the can get very butt hurt and defensive :-\
If it happens when your descending long steep inclines it's almost certainly moisture in the brake fluid which is boiling due to the heat generated by continuous use of the brake.
I am having a similar issue at the moment and also did experience it in Austria when I was there end of last month begging of this month, with mine I?m thinking it could be the delay valve or a bit of air in one of the lines, every now and again when applying the rear brake it seems to go down more than normal when I let off then reapply it it feels firmer than first time but still nothing then I feel a slight click then I get some braking, but by this time I?ve gone for the front brake as I am needing to slow down for a corner lol.
I?m gonna try giving the callipers a one over clean lube and make sure the pistons are all free, then give the brakes a bleed and see how it goes.
Have you the linked brakes. How was the new fluid introduced to the system, drained and refilled or drawn through with an air bleeder. On the linked brake bikes air can get trapped in the secondary master cylinder on the front left caliper, it has to be removed and turned to a different angle whilst bleeding.
Thanks for the replies everyone. The system was drained and then refilled by the dealer. Not sure what their method is.
I wonder if I've got a pin hole leak someone in one of the lines that's able to squeeze thinner air through it which causes hiccups in the system. I don't use much braking down hill - i usually let the engine do that in second gear.