Brake lever tightness after changing lever

[ian48th]

Looked for a thread on the subject... feel free to point me there if it exists.

I finally broke down and got some CRG levers to replace the stock levers on my 2000 M900 and I'm having trouble with the front brake.  Initially after replacement it felt tight, so I took it easy, fortunately, because it quickly tightened up on me and by the time I pulled to the curb it was totally locked up.  I reinstalled the original and was able to ride the mile back home.  It may be that I had not gotten the plunger piece seated properly against the master cylinder.

A 20 minute test ride with the original lever was okay, but it still tightened up, just not to the point of locking up.

Now the new lever is back on and it still feels too tight, like it did before locking up on me.  I've fiddled with it a bit, but before continuing thought I'd ask if there are tricks to getting the original feel back.  The lever appears to have the exact same geometry as the original and it's a CRG, not a cheap knock-off, so I think it's just a matter of getting it installed correctly.  The plunger appears to be fully seated in the pivot piece in the lever.  The spring and rubber seal on the master cylinder appear to be in good condition, too.

Thanks.

[Speeddog]

<<<SNIP>>>
not gotten the plunger piece seated properly against the master cylinder
<<<SNIP>>>
Thanks.

Yes, something is clearly not right

What master cylinder is it?

[stopintime]

... and part number on the lever?

[Buhgaboo]

Sounds like you adjusted the plunger or what ever it's called...your smart to take it easy...there is a screw ...flat head ...back it out 1/4 turn ...you have closed the return circuit and the fluid will not return to the reservoir...as it heats up it expands and as it expands it moves the pistons and clamps down on the rotor ...parked...or hurled over the bars with little warning....back it out and everything is fine

[Howie]

You want 1.5-2mm play at the lever.

Alternative method:
Lightly sqeeze the brake lever, cover off if it is a coffin reservoir.  Emphasis on lightly in that case, as you can get a big squirt resulting in paint damage.  Also protect the area with rags and have water around.  Check for surface movement in the
reservoir.   Continue to slightly screw in the adjuster and check for fluid movement.  When you no
longer see movement when pulling the lever, back out the adjuster counterclockwise one full turn, and check for
movement again.   Now you know the return port is open and you have sufficient free play to compensate for expansion.

[ian48th]

The lever is a CRG RC2 (small pivot, AB-521).

The plunger, as I call it, is not adjustable.  It just fits into a hole in the cylindrical piece that fits into the lever.  See pic below.

The original and new levers appear to have the exact same dimensions, but it feels like I have to compress the master cylinder a tiny bit to get the lever on.  I don't see any movement in the fluid when pulling the lever with the reservoir lid off.  I've tried bleeding it a bit at the master cylinder, which hasn't improved it.  Feels like I'm missing something.

I'm tempted to modify the plunger thingie to shorten it, but that's a one-way ticket and I'm no machinist.  Willing to do it if that's what's called for.  Or widen the pivot hole of the lever?



Thanks for the feedback!

[Speeddog]

~~~SNIP~~~ 
Or widen the pivot hole of the lever?
~~~SNIP~~~

No, don't do that.

For troubleshooting purposes, try installing the plunger without that spring, I suspect that's getting jammed.

[Howie]

If that does not work give CRG a call.  CRG for a coffin reservoir has an adjustment, unfortunately none on yours.

[DuciD03]

For troubleshooting purposes, try installing the plunger without that spring, I suspect that's getting jammed.

If that does not work give CRG a call.  CRG for a coffin reservoir has an adjustment, unfortunately none on yours.

- can you reuse the pivot and plunger for the oem in the crg? -

On some plungers its sealed with a plastic (hot glue?) that you have to dig out to adjust the slotted screw (as noted above); I've had to adjust on several; your local duc / moto shop might have different length plungers or threaded screw adapters. I had to thread the cylinder holder & plunger screw once with a tap to get the screw in deeper

Also - check - to see the reservoir isn't over filled (break fluid expands when heated and  ... -

[ian48th]

I may have it sorted now, but the test drive will have to wait for a day or two due to work and a big dinner party...

I noticed that the plunger thingie wasn't getting fully seated into its hole (sounds like a dirty joke coming on).  So in the bottom of the hole - I had to use a magnifying glass - there was something like dried glue that was in the way.  A little gentle drilling and scraping and now it sits about 1.5mm farther in and the lever feels better.  Don't recall if I put something on the pin or not, but it did seem to be a bit cruddy when I initially removed it.  Shrug.

I'll follow up after a proper test ride, hopefully within a couple days.

[koko64]

Howdya go?
Does the pin seat on the shoulder or end?

[ian48th]

The problem seems to be solved now.  After getting the crud out of the bottom of the hole the pin now sits all the way in - it rests on the ledge, countersunk so to speak, just a little down inside the cylinder.  Before it wasn't quite fully seated, but it was hard to see that there was anything in the hole to block it.  I zigzagged around the neighborhood for twenty or thirty minutes with lots of stop and go braking and no issues.  So let's hope that's the end of the story!

[DuciD03]

The problem seems to be solved now.  After getting the crud out of the bottom of the hole the pin now sits all the way in - it rests on the ledge, countersunk so to speak, just a little down inside the cylinder.  Before it wasn't quite fully seated, but it was hard to see that there was anything in the hole to block it.  I zigzagged around the neighborhood for twenty or thirty minutes with lots of stop and go braking and no issues.  So let's hope that's the end of the story!

you did it! .... hopefully hit the nail on the head.

[DuciD03]

... all still good with that break lever?

[ian48th]

Yup, all still good with the lever.