Hi all,

I'm new to the site and new to CBR's. I did a quick search and was unable to find any information pertaining to my situation.

I have a 93 CRR 600F2 in fairly decent shape. After about 10 minutes of riding the front brakes will slowly start to lock up. As soon as I stop I am unable to move the bike at all until I release the pressure on the brakes (loosing the bleed valves on the calipers).

I have a very good friend who is very familiar with working on bikes... we rebuilt the master cylinder (seals) and rebuilt the calipers (seals, good grease up etc). However, while this appears to work I get back on the road and I have the same issue. The dealer I have taken the bike to doesn't really seem to know what is going on and is suggesting to replace the master cylinder in full.

I'm hoping that someone on here has come across this before and/or knows whats going on and can give some assistance.

Thanks!

 

are you still running the stock, rubber brake line?

 

old rubber brake hoses will expand under pressure, then collapse internally and act like a one way valve keeping a little pressure applied to the calipers.

 

I can only assume, that when you worked on the calipers, you made sure that the OD of the pistons were cleaned well...no rust or pits, and such??

 

74deamon - I talked with the dealership today, they are going to give the brake lines a good look over tomorrow and get back to me.

JNS - Yeah, the calipers and the pistons looked good. The seals weren't in good condition but we replaced them and now everything looks in prime condition.

 

Are they floating properly on the hanger-pins? If they aren't, squeezing the brakes
could force the "dead" side against the rotor and then they won't back-off.

Ern

 

Yeah, they are floating free... the pressure is even across the whole caliper when it happens.