Author Topic: Rear Brake Failure - Vstrom AL2 650 2012  (Read 1922 times)

0 Members and 1 Guest are viewing this topic.

Offline lekyuk

  • Member
  • ***
  • Joined: Mar 2015
  • Posts: 80
  • Bike: DL650 L2
Rear Brake Failure - Vstrom AL2 650 2012
« on: November 14, 2017, 09:03:54 »
Hello,

Just riding in the morning the rear brake resistance completely disappeared and became ineffective. I stopped the bike and checked and the rear pads were not moving. Realised there was nothing I could do there and then so rode the short distance to work noting that the resistance came back and it seemed to start working again but perhaps not as sharp as they were.

Bike has done 25k. I've never changed the fluid (I know I know) but can anyone point me to the most obvious place to start. The bike is in used every day so can't imagine the piston ceasing in the caliper. It was serviced about 6 months ago, I do look after the caliper on the frequent pad changes.

I think they work by pressing the brake that pushes up the push rod into the brake fluid housing down the brake line to the caliper. My guess would be is might be a seal on the push ride thingy before the reservoir. No sign of a fluid leak but right now the reservoir could be empty. I couldn't check.

Any suggestions? I will change pads and fluid this weekend anyway but I need to get the immediate issue fixed (bloody garage has shut as they've gone to Valencia for moto GP!!!....I'm jealous).

Leky
2012 AL2 650 V Strom

Offline tallpaul

  • Member
  • ***
  • Joined: Dec 2013
  • Posts: 10386
  • Tastier than the Barrow-in-Furness bus depot...
  • Bike: 2016 Yamaha XT1200ZE
  • Location: Whitworth, Lancashire
Re: Rear Brake Failure - Vstrom AL2 650 2012
« Reply #1 on: November 14, 2017, 11:26:28 »
I would start with the rear master cylinder as it doesn't seem to be pushing fluid reliably. May need rebuilding. If the issue is a leak they tend not to fix themselves and just leak all the time. If the issue is with the abs pump then that is a bigger problem.
Old enough to know better, but still too young to care...

Offline boosabuser

  • Member
  • ***
  • Joined: Dec 2016
  • Posts: 32
  • Bike: 2014 Strom, CZ125 resto
  • Location: Hampshire
Re: Rear Brake Failure - Vstrom AL2 650 2012
« Reply #2 on: November 14, 2017, 20:49:00 »
On my 1000, my rear brake almost disappeared as well and I had a look last weekend
It turned out (In my case) that the caliper is single Piston and relys on the whole caliper sliding on a pin slightly to bring the second pad in to play
This pin is encased in a rubber sleeve that passes through a Round lug moulded in to the caliper
Dampness has got between the lug and the rubber slowly squeezing the rubber against the pin effectively seizing it and preventing the caliper from moving reducing the braking effort

Removing and cleaning the pin, carefully removing the rubber sleeve and clearing out the oxidation from the lug, regreasing assembly all took about 90 mins

My local Friendly dealership said that it is a good thing to do before winter to prevent issues

Offline lekyuk

  • Member
  • ***
  • Joined: Mar 2015
  • Posts: 80
  • Bike: DL650 L2
Re: Rear Brake Failure - Vstrom AL2 650 2012
« Reply #3 on: November 14, 2017, 21:07:23 »
Thanks! I'm changing pads this weekend and will clean everything. On ride home it was fine but I took it easy. I was thinking that heat may have played a part as I filter and ride the rear brake a lot in tight traffic. Perhaps ceasing when hot.

If this was and ABS wouldn't it affect both brakes, front and rear?





2012 AL2 650 V Strom

Offline greywolf

  • Member
  • ***
  • Joined: Dec 2011
  • Posts: 5262
  • Location: Evanston IL USA
Re: Rear Brake Failure - Vstrom AL2 650 2012
« Reply #4 on: November 14, 2017, 21:37:26 »
ABS would not be affected. A wheel has to lock up to engage ABS.
Pat- 2007 DL650A was ridden to all 48 contiguous states. 2012 DL650A outlasted me.
Nicknames I use to lessen typing, Vee = 2002-2012 (K2-L2) DL1000s. Veek=2014+ (L4+) DL1000s. Wee = 2004-2011 (K4-L1) DL650s. Glee = 2012+ (L2+) DL650s

Offline boosabuser

  • Member
  • ***
  • Joined: Dec 2016
  • Posts: 32
  • Bike: 2014 Strom, CZ125 resto
  • Location: Hampshire
Re: Rear Brake Failure - Vstrom AL2 650 2012
« Reply #5 on: November 15, 2017, 19:08:02 »
ABS constantly checks individual wheel speeds and reacts is there is a significant difference front to rear, it also monitors the brake light so it can tell if you are braking (the same system also works with the traction Control)
If you suffered brake fade due to heat the system would only see brakes applied and unless the wheel speeds are vastly different would not intervene

Offline paulo

  • Member
  • ***
  • Joined: Mar 2012
  • Posts: 62
  • Bike: DL650A L2
Re: Rear Brake Failure - Vstrom AL2 650 2012
« Reply #6 on: November 17, 2017, 08:36:37 »
Just a quick word of caution: I would advise not to remove the sliding pin by itself. Its extremely easy to cross thread it when bolting it back in, which may then mean a replacement caliper is needed. Remove the caliper assembly as one, clean and regrease the sliding pin etc. I use Mintex Ceratec for this. 

Offline boosabuser

  • Member
  • ***
  • Joined: Dec 2016
  • Posts: 32
  • Bike: 2014 Strom, CZ125 resto
  • Location: Hampshire
Re: Rear Brake Failure - Vstrom AL2 650 2012
« Reply #7 on: November 17, 2017, 19:21:51 »
+1 for Paulo I should have mentioned that, apparently it is relatively easy to cross thread that pin, the trick is not to rush it, if you can't spin it in a few turns then something is wrong, don't resort to force also I am a bit anal when it comes to cleaning threads before asssmbly