XJ brake lever hard to pull?

[ljasonb]

My front brake lever is harder to pull than any other bike I've had. When used alone it seems to stop as well as that single rotor can be expected to. With help I've switched to steel brake lines all around. That came with a master cylinder cleaning and fluid flush of course.

I'm still a bit worried about the lever pull. It doesn't move much. I don't have much adjustment left on the plunger screw - it is mostly backed out. The lever moves little now and even less if I run the screw down.

1) Should the front brake really haul my XJ to a quick stop by itself?
2) Should I be concerned about the short hard pull?
3) If so, what should I do about it?

Thanks experts!!!

[WMarshy]

The front brake is approximately 70% of your stopping force. It absolutely should bring your XJ to a quick stop even without your rear. Am I reading you post wrong...do you have both calipers up front?

The short pull shouldnt be a problem, you want a nice firm feel to it and stainless lines help that.

[crazy steve]

Are you sure you have the original master cylinder on there? The 'split braking' system of the LH/XJ used a smaller-bore master for the single front caliper, if a XS dual-caliper master (with a larger bore) was swapped on that would be the result.

As to how 'good' the single front brake should be, these bikes were never known for the excellence of their brakes.. Yes, it will stop the bike, but not nearly as well if all brakes are used. Yamaha put put dual discs on for a reason.

If you have the correct master, you might want to look at the caliper. If it hasn't been gone through it's likely got the typical corrosion inside, it may not be releasing all the way. If the master needed cleaning, there's no doubt the calipers need it too...

[natemoen]

The front brake is approximately 70% of your stopping force. It absolutely should bring your XJ to a quick stop even without your rear. Am I reading you post wrong...do you have both calipers up front?

Yes, and no.....

On the XJ you have the split brakes as steve was talking about. Only one caliper is operated by the front brake handle. The other caliper is operated by the rear brake pedal along with the rear brake.

[WMarshy]

Yes, and no.....

On the XJ you have the split brakes as steve was talking about. Only one caliper is operated by the front brake handle. The other caliper is operated by the rear brake pedal along with the rear brake.

For some reason I always thought you could still operate both front calipers from the front brake handle. If that was true then you'd be operating all three... wow, I'd toss that linked system b/c I couldnt imagine not having both my front brakes when I squeeze the handle!

[CatatonicBug]

For some reason I always thought you could still operate both front calipers from the front brake handle. If that was true then you'd be operating all three... wow, I'd toss that linked system b/c I couldnt imagine not having both my front brakes when I squeeze the handle!

With the split system, the idea is that you should be relying on the rear brake pedal for most of your braking (but still using BOTH brakes every time), since it balances the pressure out between both wheels. The split rear MC allows for a more controlled stop, reducing the chance of locking the brakes. Goldwings use the same setup to help stop all that weight.

The brake lever should not come all the way down to the handlebars. Once you press it all the way down as far as you can, you should still be able to get your fingers between the lever and the grip.

[ljasonb]

All calipers and both m/c's were cleaned thoroughly when the lines were swapped for stainless. As far as I can tell via my admittedly limited experience with XJ's the "brakes" (calipers, pad, pistons, lines, fluid) are indeed working as intended.

My concern is if my front lever is acting properly. When I use it alone, it does stop the bike - eventually. Maybe not so much a surprise b/c of the aforementioned linked system.

I'm still not so sure about the lever action/feel though. It's hard and travels little. In fact, it comes to rest nearly outside of my reach. There's PLENTY of space between the lever and the grip when compressed as far as I can pull it. I have the plunger adjustment screw backed nearly all the way out. If I tighten it at all the pull is VERY hard, the lever moves VERY little, and it comes to rest VERY close to out of reach.

[crazy steve]

Do you have the right lever? Yamaha used a couple of different designs on the various bikes, maybe somebody swapped on the wrong one? Should look like this:


Another possibility could be that the end of the master piston is worn. There's been reports that the adjustment screw will wear a 'divot' in the end of the piston, hanging up the screw, limiting lever travel and making applying the brake hard. Removing the piston and filing the end flat again should do the trick...

[ljasonb]

That's the lever I have. Don't suppose I'm really lucky and you have a picture or two of the master piston and it's removal?

[crazy steve]

Well, first check to see if the end of the piston is flat; you can do that without disassembling the master, just remove the lever. If there's a depression worn in the end, that's the likely problem. The adjustment screw has to 'slide' across that surface as the lever is pulled, if there's a divot the screw will hang up.

To disassemble the master, look here: http://www.xs11.com/forum/showthread.php?t=37209

[ljasonb]

My bolt was not rounded at all. It was just a regular bolt. I rounded it off and cleaned up the piston end as much as possible without disassembling the m/c.

No change in lever pull or feel.

Could the stock bolt be different on XJs than in your tutorial?
Guess my only option now is rebuild the m/c and hope for the best?

Thanks again!

[crazy steve]

Was there any depression on the end of the master piston where the adjustment bolt contacts? If there is, that's likely the problem. The adjustment bolt and lever are the same as the XS, so that's not it.

Otherwise, I think you'll need to take the master apart; it may be misassembled...

[ljasonb]

There was a depression. I didn't get it all filed away. Are new pistons available?

[CaptonZap]

One thing to try before you tear the master cylinder apart;
Apply pressure to the handle. Have some one crack the bleed screw on the caliper that the brake line goes to. I think it's the right side.
The handle should go down. Just like bleeding the brakes.
If it does, that would indicate that the master cylinder is OK, and you have a really good setup, cause every one I've dealt with had a bit of give, even with stainless lines.
If it doesn't go down farther than it did before you cracked the bleed screw, you have a problem in the master cylinder. CZ

[crazy steve]

There was a depression. I didn't get it all filed away. Are new pistons available?

Yes, in complete rebuild kits; check with 'Chakal' over at the XJ forum, as he seems to be the only supplier. But if the only problem is the divot, simply file yours until it's flat again...