Need help with front brake lever misbehaving

The front brake lever on my 6th gen has started misbehaving since the last couple of weeks. I am not able to figure out what is the reason behind it.

When I pull the lever for braking, it presses as if there were two levels of braking. The brakes work, but just a little bit for level 1. When I apply more pressure, the brakes are applied really hard as if it were level 2, like almost 70-80%. I can feel some hesitation in the lever going from level 1 to 2 with some friction. This was not the case a couple of weeks ago and the brakes worked just as expected. I checked the brake fluid level and it s topped off as well.

A friend of mine who owns a VMAX suggested me today that the master brake fluid cylinder is the cause of problem and I should replace it. If anyone has been in this situation before or knows what is happening, please suggest the cause of the issue. And if you could fix it, please give me the solution how you fixed it. Front brakes not working properly scares me.

 

The brake fluid is unlikely to be a problem, as long as there is enough.

Check the brake lever pivot is well-lubed; pull it off, clean and grease the pin.

If that doesn't solve your problem you need to get into the calipers. First off I would clean and lube the sliding pin mounts, the calipers need to be able to slide freely side-to-side to transfer braking force to the pads.

Next up would be to check the pistons are moving freely, and if not you should clean the pistons. After that you may need to re-furbish the pistons with new seals.

 

Thanks for the help. I'll work on it this evening and update you on how it goes.

 

I have this issue with my bike and I have done most of the above, save replacing my master cylinder. I have some aftermarket levers that look exactly like stock. I have taken the levers off and polished both the levers and the MC where they mount to see if it was friction. I inserted nylon washers around the pin to take up the slop of the lever. I found some washers at Lowes and slid them in around the pin, at the base of the lever, in the little gap of the MC where the lever slides in. I have greased it and I have even tried graphite. I've tried it without the washers and there was no difference, except for looseness in the lever, up and down.

When I replaced my pads, I took a small stainless steel wire brush and cleaned up all my pistons as much as possible. I too thought it was the MC, specifically the plunger that the lever acts against, however, I noticed that when I removed the lever and added grease to the pin, it would operate smoothly for a while, then start sticking again. I have taken the levers off and hit everything with brake cleaner and even clean, they would work for a while, then start sticking. When I tried graphite lock powder, that too worked for a bit, then as usual, they would start sticking. SO, I tried just adding graphite without removing them and that made a difference too. For now, I am going to just keep touching up the graphite until I get new levers and see of that makes a difference. I don't know what it is that is causing this. I know it has something to do with lubrication and I have even used synthetic brake caliper grease as it the best grease I have right now and again, that only works for a time. When I had my levers off last time, I took some 400 grit wet dry sand paper and polished the space where the levers go and that may have helped some. Maybe I'll try brass washers, or no washers again, I don't know.

Maybe some $25 EBay levers or a stock Honda lever. Another option is to replace the plunger on the MC, that is available online and the best price seems to be from Ron Ayers, MASTER CYLINDER SET 45530-MA4-671 http://www.ronayers.com/oemparts/a/hon/5053f5bef870021c54be7c5b/front-brake-master-cylinder but I don't know if shipping is a lot or not. I just know that I can't seem to find any reason for this other than lube, but nothing I have tried is a permanent solution.

 

That sounds scary. I'd start with some WD-40 lubrication today and see how it goes. If this does not work I'll try using some grease. If both fail then I'll look at the other options. I had never heard of this problem before or experienced it. As long as it is a lubrication problem that's not gonna get worse, I won't be much worried.

 

I think Cadbury has it spot on. The trouble isn't in the lever or mc.

 

In your experience can the calipers have such a huge gouge or significant fluid crystallization such that you can feel the brake deploy in two discrete steps from the lever? Even if that is the case, can such occur all at once on well-operating brakes? I yield to your guys experience but that sounds fishy to me.

I am wondering if the fluid is deploying in two steps. A line is crimped, and takes severe pressure to push past the crimp. I don't know the linked system but is there a fluid switch which can be acting up?

 

Regarding crystallisation, I recently bought a complete CBR954 brake system off ebay and the master-cylinder piston was seized solid with a crystal deposit. It cleaned up nicely and now works beautifully.

I've certainly had a sticky feeling brake lever that was simply due to a lack of grease at the pivot points, and easily fixed with some maintenance.

There's no switch or other valving on the LBS front brakes; there a direct line from the master to a splitter then down to each caliper. The front brakes drive the back only through the rotation of the LHS caliper pressing on the secondary master cylinder.

The OP was looking for a source of friction that needed to be overcome before full brake pressure was being applied by the pads to the disc; I was suggesting the steps above in order of difficulty, no point rebuilding the calipers if it just needed some lube at the lever pivot.:smile-new: But if I was a betting man I would suggest a build up of dirt/corrosion on one or more of the pistons in the caliper that are causing binding against the seals, so that one piston extends easily but it takes more force to get the other to move.

 

I took thought of the Pistons, but I polished every piston on the brakes, front aND rear, with a stainless steel brush. When the lever is friction free, my brakes are very smooth.

 

So, it was the simplest of fixes I could think of. It was a lubrication issue. I used some of the chain lubricant spray with the straw like nozzle to spray in the moving parts holding the lever. This fixed the issue and the brakes are like new again. Thank you guys for the help. Your replies will definitely help in some winter maintenance for the brakes when I won't be spending my time riding.

After the fix, I thought it was dumb to post the question since it was that simple of a fix. But the detailed replies on how to work on every part of the brake was very helpful. Thanks guys. :wink:

 

Glad to hear that it was an easy fix Suraj! And thank you for posting your conclusion to the issue.

 

my guess was wrong, so shame on me ! :grumpy:

 

You referenced the reply that said to check for lubrication in brake lever pivot. You were right then. You are wrong now