Gen 3 rear brake play

[NiK]

I suspect (yet another) bad design in the rear master cylinder. Probably bad gaskets letting some moisture in overtime.
Mine already was repaired/replaced. On a '18 bike!

[CaptainTrips]

The rear master also tends to get cooked by heat from the engine and exhaust piping. The temperature cycling will draw moisture into the vented reservoir.

[CraptainC]

Originally Posted by CaptainTrips

The rear master also tends to get cooked by heat from the engine and exhaust piping. The temperature cycling will draw moisture into the vented reservoir.

Interesting point CT...  once moisture is drawn-in to the the brake fluid (which is hydroscopic), the heat from the exhaust and engine could cause the moisture to vaporize further contaminating the brake fluid and reducing the effectiveness of the braking...
Doesn't quite explain why people see the loss of rear brake after a winter lay-up, unless the contamination had already happened prior to over-wintering (yes I know - fair weather rider  ), and a period without regular use caused the air / moisture to collect in a critical part of the master cylinder 

Anyways, from now on I'll be flushing the brake fluid routinely each spring when I check the rest of the fluid - its a quick job & better safe than sorry !
 
CC     

[mcchoc]

I've now discovered that - on the back side towards the rear of the brake pedal - there are two small metal posts.  One is the anchor point for the pedal's  return spring, the other little post has nothing attached to it, but it does have a metal bracket just above it with a round hole in it about the size of your little finger.  Looks like earlier Tigers must have had the brake light switch mounted here? 

So I guess the Gen3's switch works off hydraulic pressure further downstream from the master cylinder?  I will change the fluid very soon; what sort of brake fluid is compatible/recommended please?

Incidentally, after two and a half years of ownership, the bike is finally starting to feel like a part of me.  I've always had sports-tourers (FJ1200, K1200RS, K1300S) so it is quite a change of feel on the road.  In preparation for this winter's planned three week ride along the length of Patagonia, and as a recent convert to type 2 diabetes at the age of 67, I am taking longer day rides - despite the price of petrol.  Today I clocked over 200 miles going from home in Goole to Hawes via York, Pately Bridge, Kettlewell and Upper Wharfedale then heading east to Leyburn,  Bedale and Thirsk, climbing Sutton Bank then through Malton to my favourite pub at Burythorpe - then along the escarpment edge of the Wolds, diving down into Pocklington and home. 

The Tiger was superb on these Yorkshire backroads, never missed a beat and retuned 54 mpg, confirming it was the right choice as a 'forever' ride for this pensioner.   

[CraptainC]

Sounds like you are making the most of the good weather McChoc, and Patagonia sounds a great adventure
I'm due to retire later this year, and once my hip has been fixed I have a bucket list of trips to work through also 

As for the brake fluid, - I used standard DOT 4 hydraulic fluid in mine ... pushed a couple of reservoir's worth through, which only took 10 mins.

Good luck
CC

[CaptainTrips]

Originally Posted by CraptainC

Sounds like you are making the most of the good weather McChoc, and Patagonia sounds a great adventure
I'm due to retire later this year, and once my hip has been fixed I have a bucket list of trips to work through also 

As for the brake fluid, - I used standard DOT 4 hydraulic fluid in mine ... pushed a couple of reservoir's worth through, which only took 10 mins.

Good luck
CC

I like to use a cheap Mityvac knockoff to suck the fluid through from the reservoir. It's quicker and you don't have to pump the brakes.

[mcchoc]

Did a quick rear brake bleed - no bubbles. Then lengthened the activation rod by two full turns - brake light fires up just as pedal resists and pads start to bite, which is now much nearer the top of pedal’s travel. 

Now I’m a lot happier when rushing slightly too quickly into wet, shiny roundabouts.   

[CraptainC]

Originally Posted by mcchoc

Did a quick rear brake bleed - no bubbles. Then lengthened the activation rod by two full turns - brake light fires up just as pedal resists and pads start to bite, which is now much nearer the top of pedal’s travel. 

Sounding good    Did you just bleed the brake or flush the old fluid through?  When I did mine there wasn't any 'obvious' bubbles, but the old fluid was a bit milky in initially - suggesting that either there were a lot of very small bubbles or some other contaminant ...... or this was not the problem at all & all you needed to do was adjust the rod 

Either way you are happy now - which is all that matters 

CC 

[mcchoc]

Originally Posted by CraptainC

Either way you are happy now - which is all that matters 

CC

Thanks.  I was on my own so had to lie next to the bike's nearside and bleed the nipple as I reached underneath the bike with my right hand to push down on the pedal.  The tube I used was not a great fit onto the nipple so I was happy once about ten inches of clean fluid came through, and left it at that. 

The only problem I had was getting one of the long screws for the reservoir top to pick up its thread on what I presume is a tiny 'captive' nut.  Those two screws are only just long enough to reach the nuts, so I pushed a spare screw up from underneath the reservoir to help start the thread - the holes go right through the unit.  Not a great piece of design and feels a little cheap on a premium ride. 

Now, if only the clutch's late bite point could be solved so easily . .  .