front brakes lockup while riding

[2slow]

I went up Hy 9 to ride twisties before I go work. On the way home my front brakes started to slowly lock up. At first it felt like it was losing power and gave it more gas. Then I relized it was the front brakes when felt the lever so hard without any play at all. As soon as I pulled over the front completely lock up and cant move at all. I called my nephew to bring me a wrench so I can bleed the the master, well not really bleed but to release the presure in the line. After doing so the brakes felt good again. So Im wondering what happen? Im just glad it slowly lockup not lockup all of a sudden. That would of been bad news cause I was on the freeway on rush hr.

 

[Burning1]

I'm guessing you recently 'topped up' your brake fluid, or replaced your brake pads?

Your brake fluid level was almost certainly above the full line. As the brakes heat up, the fluid expands. Since there's no room left in the fluid reservoir, the expanding fluid starts pushing the pistons into the rotors.

Whenever you install new pads, always set the fluid level to the 'full mark' and no higher. Never top-off the fluid - the fluid slowly goes down as the pads wear, and the pads will need to be replaced before the fluid hits the low mark. The fluid is *not* consumed under normal circumstances.

 

[aram]

I've heard that sometimes cheap aftermarket levers can cause that to happen too.

 

[Burning1]

Yeah... If the lever doesn't permit the master cylinder to fully relax, the brakes become a 'closed system.'

 

[2slow]

I'm guessing you recently 'topped up' your brake fluid, or replaced your brake pads?

Your brake fluid level was almost certainly above the full line. As the brakes heat up, the fluid expands. Since there's no room left in the fluid reservoir, the expanding fluid starts pushing the pistons into the rotors.

Whenever you install new pads, always set the fluid level to the 'full mark' and no higher. Never top-off the fluid - the fluid slowly goes down as the pads wear, and the pads will need to be replaced before the fluid hits the low mark. The fluid is *not* consumed under normal circumstances.

I believe you are right. I just recently replaced the fluid recevior. There is no full mark or low mark on it just a little peak hole on the side. I will go check the fluid level again. Thanks

 

[Flying Pig]

I'm guessing you recently 'topped up' your brake fluid, or replaced your brake pads?

Your brake fluid level was almost certainly above the full line. As the brakes heat up, the fluid expands. Since there's no room left in the fluid reservoir, the expanding fluid starts pushing the pistons into the rotors.

Whenever you install new pads, always set the fluid level to the 'full mark' and no higher. Never top-off the fluid - the fluid slowly goes down as the pads wear, and the pads will need to be replaced before the fluid hits the low mark. The fluid is *not* consumed under normal circumstances.

And if you don't believe Chris, go look for the video where a trackrider had the camera on the tank, and crashed before you could blink because his brakes were locked up....

 

[Flying Pig]

I believe you are right. I just recently replaced the fluid recevior. There is no full mark or low mark on it just a little peak hole on the side. I will go check the fluid level again. Thanks

Usually that hole has 2 lines, the bottom one for being low, upper for full.

 

[msethhunter]

What kind of fluid did you use?

 

[2slow]

What kind of fluid did you use?

I think I used DOT4 I dont remember.

 

[2slow]

I've heard that sometimes cheap aftermarket levers can cause that to happen too.

I did replace the levers too but they are not the cheap ones. I think they are CRG something like that

 

[msethhunter]

I think I used DOT4 I dont remember.

Well it's real important, you need to find out.

You can mix dot3 and 4, but you can't put dot5. If you used dot3, it could be to much heat for that fluid to take, causing it to heat up and expand to much.

 

[2slow]

Well it's real important, you need to find out.

You can mix dot3 and 4, but you can't put dot5. If you used dot3, it could be to much heat for that fluid to take, causing it to heat up and expand to much.

Before I put in the fluid I did make sure it was the right one. I read the manuel book I just don't remember if it was a 4 or a 3 because I have both fluid.

 

[Enchanter]

I did replace the levers too but they are not the cheap ones. I think they are CRG something like that

I bet this is the cause of the issue. What bike?

 

[Motech]

Fifty bucks says overfilled.

Another fifty bucks says this was no way caused by fluid type.

BTW, DOT 3 has no place in any bike regardless what manuals say. DOT 4 or 5.1 only.

 

[2slow]

I bet this is the cause of the issue. What bike?

2005 zx6r. So I looked at fluid with the lid off. The fluid is a little over the peak hole. At the center of the peak hole it say MIN. So I didn't flush anymore out. I took the bike out for about 15min so far it's ok. Hopefully it stay that way.

 

[motobecane10]

Fifty bucks says overfilled.

Another fifty bucks says this was no way caused by fluid type.

correct

 

[Warrior Princess]

I am not saying I know this, but brake fluid is hyd fluid becasue hyd fluid cannot be compressed. It has not oxygen. Maybe the other oils might expand but not by much. Again I could be worng, but just a thought.

Your thoughts on this has been very good. I believe you are correct. Just wondering.

 

[Warrior Princess]

Now I have heard of air lock. I dont quite understand it but I have been told it can cause hyd lockup.

 

[louemc]

2005 zx6r. So I looked at fluid with the lid off. The fluid is a little over the peak hole. At the center of the peak hole it say MIN. So I didn't flush anymore out. I took the bike out for about 15min so far it's ok. Hopefully it stay that way.

Well since You have a Kawasaki...You might find the ZX-10R.net site to be interesting.

There is a butt load of ZX-10 riders that have put levers on that they say look to be exact copies of the CRG ones...and had their brakes lock up, just exactly like yours did.

 

[2slow]

Well since You have a Kawasaki...You might find the ZX-10R.net site to be interesting.

There is a butt load of ZX-10 riders that have put levers on that they say look to be exact copies of the CRG ones...and had their brakes lock up, just exactly like yours did.

I know this mite sound stupid. But if it happens again I'll put back my stock levers. I would hate to toss out $200 not knowing if it really was the levers. I'll just take it easy for now and keep applying little break at a time and feel the lever if starts to harden.