piece of foam in front master cylinder reservoir?


4 replies to this topic
  • rojapar

Posted January 17, 2015 - 05:44 AM

#1

long story short, i put on some cycra pro bends and the way the front brake line came out of the master cyliner, it would run right through the aluminum cycra guard. 

 

there are two finger-like projections on the master cylinder the brake line bolts between.  i had to take the line loose and run it below the bottom finger to make it work.  i hope this wont hurt anything.

 

anyway, took the master cylinder cap off to add fluid and bleed the front brake.

 

there was the cap, then a black rubber piece under than, and then floating in the master cylinder brake fluid was a flat piece of foam just floating around in there.

 

it was about 1/8 inch thick hard foam and was cut to roughly the shape of the inside of the master cylinder.

 

is that piece supposed to be in there?  if so, what is it for?   ive done a few brake line replacements on street bikes and have never seen anything like that floating around in the fluid.  i just wanted to make sure its supposed to be in there.

 

thanks



  • Rocket416

Posted January 17, 2015 - 09:58 AM

#2

Yes it's supposed to be there. I've bought a couple new bikes in the last 2 years and everyone had the foam you are referring to. I'm not sure of the purpose though.

Edited by Rocket416, January 17, 2015 - 09:59 AM.


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  • grayracer513

Posted January 17, 2015 - 09:58 AM

#3

The float is to help suppress the fluid from sloshing away from the cylinder fill port at the bottom of the reservoir when the level gets lower than about 3/4 full.  It does belong there.



  • PsychoSane

Posted January 23, 2015 - 03:42 PM

#4

long story short, i put on some cycra pro bends and the way the front brake line came out of the master cyliner, it would run right through the aluminum cycra guard. 
 
there are two finger-like projections on the master cylinder the brake line bolts between.  i had to take the line loose and run it below the bottom finger to make it work.  i hope this wont hurt anything.


That can be a bad idea.

One day this summer I was riding in the woods after it rained for two days. The top soil was thoroughly soaked and covered with a dense layer of fallen leaves. I was ripping through a tight section and my front tire washed out as some loose soil gave way. I instantly picked the bike up so I could give it a quick mechanical once over. Everything looked ok, I felt ok, so I took a short trail leading to a small practice track.

About halfway through my third lap I realized that I had no front brakes. The earlier impact had moved the banjo fitting enough to loosen the bolt, and the fluid slowly bled out until I had no brakes.

One good thing about it, as I went through those last two corners without front brakes I learned that I could carry way more speed than I previously thought. =)

Since then I've thought about shrink wrapping a piece of thin piece of rubber around the banjo fitting as a spacer, so that the fitting has no room to move in those two projections.

  • rojapar

Posted January 23, 2015 - 04:18 PM

#5

That can be a bad idea.

One day this summer I was riding in the woods after it rained for two days. The top soil was thoroughly soaked and covered with a dense layer of fallen leaves. I was ripping through a tight section and my front tire washed out as some loose soil gave way. I instantly picked the bike up so I could give it a quick mechanical once over. Everything looked ok, I felt ok, so I took a short trail leading to a small practice track.

About halfway through my third lap I realized that I had no front brakes. The earlier impact had moved the banjo fitting enough to loosen the bolt, and the fluid slowly bled out until I had no brakes.

One good thing about it, as I went through those last two corners without front brakes I learned that I could carry way more speed than I previously thought. =)

Since then I've thought about shrink wrapping a piece of thin piece of rubber around the banjo fitting as a spacer, so that the fitting has no room to move in those two projections.

well, after destroying my rc high bars thanks to the got damn cycra bark busters, the bars are scratched to hell and not being used.  i put on a set of windham bend pro tapers and the line has plenty of room now.

 

i swear, ive never been so frustrated with a bike as this one.







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