Combined braking system problem
 

Hi,

I have just bled and replaced all the brake fluid and overhaulled by rear brake caliper and now I have a problem which is driving me nuts :icon_gunhead:

Rear brake pedal works fine on the rear, front brake lever is working fine on the front but the rear caliper does not seem to work on the front lever.

there is fluid going through, pistons are loose enough to operate but there is no pressure to the pistons????? :icon_hyper:

I have being cranking on the secondary cylinder valve whilst bleeding fluid but no progress!! Any suggestions?

The bike is a '93 CBR1000F

Cheers

Rick

The combined braking system works when the bike is moving. This is from the shop manual.

"In response to the braking force applied by the front caliper onto the spinning brake rotor, the caliper (they're referring to the front left caliper) is pulled in the direction of wheel rotation, around its lower linkage pivot. This forward caliper motion also acts on one end of a pivoting "L" angle link, the other end of which is connected to teh secondary master cylinder. This direct pressure on the secondary master cylinder is then transmitted to the outer pistons of the rear caliper by way of the in-line proportional control valve."

Reference Thread :

https://cbrforum.com/forum/cbr-1000f...-model-102549/

There was no mention of the orifice bolt in that thread. You need to push fluid through the lines that run the length of the bike that pass through the above mentioned in-line proportional control valve. I posted the sequence in the how to section. -----> LINK

DUH!!!!

If the rear brake is activiated by the secondary cylinder of course it won't work on the lever!!!!!
Why doesn't the haynes say something like " hey stupid - read this" ..... not work on lever!!
Answer crank the cylinder into the caliper - hey presto brake works!!!!!

Cheers Guys

That's why you have to open the orifice by backing out the orifice bolt. You would then push fluid through the secondary MC, removing any air rather than pumping it and causing a vacuum below it.

Still, I would do what I posted in my last post. That way any air trapped is sure to be expelled.