2020 California 1400 Rear Brake Master Cylinder Heat Shield?

[Skysailor64]

I recently got stuck in stop and go but mostly stopped traffic on I95 South on a hot July day and the heat from my 2020 California 1400 Touring was noticeable to say the least. Burning my calves on the injector covers will be left to another discussion but at one point after about 45 minutes of stop and go I hit the rear brake only to realize it was compromised and unusable. I have read of this phenomenon but thought my 2020 model had been modified to ameliorate this problem. I eventually got off the highway and back home without using the rear brake and after cooling down it seems like the rear brake pedal now feels normal but I have not had the time or opportunity to do a test run. I am wondering if there is a DIY fix such as some sort of master cylinder heat shield that can be fabricated to avoid this in the future? The bike is going in for its 12,500 mile service in a few weeks and the brake fluid will be replaced at that time. Would that be considered to be enough of a precaution to this happening again?

[normzone]

Ooh, interesting question. Thanks for the heads up.

I'll follow this one with interest, although the most challenging braking issue I ever faced was splitting lanes for four hours in pouring rain in San Francisco Bay area traffic on my '72 Eldo. I had to pump the brakes CONSTANTLY in order to keep them responsive enough to be available when I needed them.

You might want to shield the cylinder AND the line.

[guzzista]

The biggest problem is a (almost) non existent air gap between the exhaust pipe and the MC. An aluminum sheet could help deflect some heat if you can fit one .  I simply buzzed down  a bit of the casting dime shaped lug to allow some air to circulate through with a small air flap disc to make a bit of room. That can be done without undoing the brake line . So far it has worked for me and no dead rear brake  after running in slow hot traffic.

[Skysailor64]

The biggest problem is a (almost) non existent air gap between the exhaust pipe and the MC. An aluminum sheet could help deflect some heat if you can fit one .  I simply buzzed down  a bit of the casting dime shaped lug to allow some air to circulate through with a small air flap disc to make a bit of room. That can be done without undoing the brake line . So far it has worked for me and no dead rear brake  after running in slow hot traffic.

I am a bit hesitant to try that but will keep it in mind.  Am thinking of try to use this product in some fashion if I can get it into that small space: https://www.summitracing.com/parts/hsp-282080?seid=srese1&gclid=Cj0KCQjw-ZHEBhCxARIsAGGN96LoUshOpkS5Xt4jN5H2p3Ub_NkaYtP3R7TQRiNawkPzpAFOwb2y1AQaAuxYEALw_wcB

[moto-uno]

  Had the same problem on my 2018 Eldorado , Fix cost nothing but some time . I loosened all the exhaust fasteners from the head back and simply applied slight down pressure and refastened
everything , no exhaust leaks and the slight added clearance ended the brake fade when in slow hot traffic .

[Skysailor64]

  Had the same problem on my 2018 Eldorado , Fix cost nothing but some time . I loosened all the exhaust fasteners from the head back and simply applied slight down pressure and refastened
everything , no exhaust leaks and the slight added clearance ended the brake fade when in slow hot traffic .

Thanks!  I will definitely give that a try! Sounds like it would also make putting in some sort of heat shield easier as well.

[guzzista]

  Had the same problem on my 2018 Eldorado , Fix cost nothing but some time . I loosened all the exhaust fasteners from the head back and simply applied slight down pressure and refastened
everything , no exhaust leaks and the slight added clearance ended the brake fade when in slow hot traffic .

The exhaust is above the the master cylinder so down pressure( towards the ground) would bring it close to the mc not further away. So perhaps moved upwards? As for 1400 exhausts , they tend to seize at the joints , at least mine was when installing  Agostini slip ons and realigning the pipes and balance tube so careful handling , heat etc , penetrating oil etc is recommended when loosening any of that stuff.

[Skysailor64]

The exhaust is above the the master cylinder so down pressure( towards the ground) would bring it close to the mc not further away. So perhaps moved upwards? As for 1400 exhausts , they tend to seize at the joints , at least mine was when installing  Agostini slip ons and realigning the pipes and balance tube so careful handling , heat etc , penetrating oil etc is recommended when loosening any of that stuff.

Good point! I will certainly make that adjustment.  The overall suggestion to make space between exhaust pipe and brake master cylinder remains solid :)

[Dukedesmo]

Sounds like my Ducati 916.


It's a well documented fact that 916 models have a poor rear brake and that they suffer from air buildup in the line so they need regular bleeding.


There are several reasons for this but, IMHO the main problem is that the bracket that holds the master cylinder also holds the exhaust mid-pipe and that this plus, the proximity of said mid-pipe to the M/C means that it all gets very hot, along with the fluid.


AFAIK no-one has come up with a definitive cure, they just bleed the brake more often.