stiff brake pedal

[fjrjonesing]

After braking hard in traffic, I lost all the travel in my brake pedal. It's not sticking- returns completely- and it's not dragging, but press it less than 3/4 inch and it's mucho stiff. Appreciate any ideas as to remedies,

Jim in BR

otherwise perfect 07

 

[exskibum]

Replace (bleed) the brake fluid. It absorbs moisture over time (from the atmosphere, esp. in humid climates . . . even though the system is closed) and heat generated from hard braking turns that absorbed water to steam (expands out of solution to gas). Presto, no travel in pedal because of temporarily pressurized slave cylinder. Note that after the bike sits and the brake system cools, the water vapor is reabsorbed by the hygroscopic brake fluid and you typically have pedal (and pad) travel until you ride and get the brakes hot again.

 

[fjrjonesing]

Actually, I pulled a little fluid through the bleeder with my MytiVac- not much because I don't have fresh fluid. No joy. I'll do a "deeper" bleed when I get some fluid.

Kinda weird. I just hit the brakes hard once...

 

[exskibum]

Kinda weird. I just hit the brakes hard once...

Kinda weird, indeed, if one hard stab was the only precursor action.

 

[rbentnail]

Start by cycling your ABS with your test block, see what happens. No special tools needed, just a little alligator clamp patch cord. Then replace bake fluid, then cycle again.

I used method 2 of this procedure, details in your FSM. Easy-peasy!

 

[fjrjonesing]

Think this is the ticket. Thanks so much.

Jim

 

[fjrjonesing]

Ah, so what's the trick to getting the connector off? Looks like it's held by a tab to the metal piece below: do you pinch it or apply upward pressure? Seems I've tried all vectors except the one that frees it...

Jim in BR

 

[lonerider]

I used an o ring pick with a 90 degree point to pry the cover off. Some dielectric grease would make removal easier next time.

 

[fjrjonesing]

Well, I got my pedal play back but now have no rear brakes. Here's what happened:

Rather than continue to maul the connector to the ABS test block, I actuated the ABS by stopping suddenly. System worked great the first time but still a stiff pedal. I hit it hard a second time and the rear brakes locked to the point that the engine died. Limped 1/2 mile home (rotor was hot but not glowing) and bled- two front lines (everything great) then the rear. I got fluid through the front line that connects to the rear master cylinder and the brakes released, but when I went to bleed the rear cylinder I got no fluid into the MytiVac. Tried bleeding the old way, suppressing the pedal with the line open then closing, and got no fluid. Rear wheel spins normally, pedal play feels normal, but the calipers won't close.

Any suggestions welcomed.

Jim in BR

 

[fjrjonesing]

Got the test block cap off (never mind...) and ran the ABS check. Everything quivered and blinked as described, and it locked the rear brake up, just as when I stopped smartly on the road this morning. When I tried to bleed the rear, the brake released when I opened the bleed valve but I got no fluid when I pumped the MitiVac. And I no longer have a rear brake. Ran the test a couple more times, same same. Error ABS 25, which I assume is from the rear tire moving.

Bummed and defeated. Limping to the dealer in the morning...

 

[TomInPA]

Rather than rely on the Mit-e-Vac for bleeding, why not try the old fashioned way of opening the bleed valve and pressing the pedal? Go in the correct sequence and it will work.

 

[fjrjonesing]

Thanks for the response. Tried to bleed using the pedal but with the same result. No fluid.

 

[exskibum]

I'm looking forward to reading about the eventually determined cause of this weirdness and the resolution. Good luck.

 

[HotRodZilla]

Almost sounds like the rear master cylinder is toast.

 

[raymcc2]

What was the final solution? Im having the same issue on my '07. Ill send PM and hope for a response.