Bleed the rear brake

[Skeeve]

From the MGNOC website

 

The rear brake on the V11 series are prone to early wear; toward the bottom of the "Tips" column found at the above link, this is identified & resolved. Something to keep in mind during maintenance & initial prep...

[Ouiji Veck]

Nice one Skevee...

 

Take note all. I'm always blasting my back brakes with air and pulling 'em

off and working them, I just figured it was the unfortunate upside down position

loading 'em up with grit and grime. Timely too. I was just about to flush 'em for the season.

Kudos for the heads up.

[Greg Field]

Ah, the good old days. I'll have to fire up the MGNOC Tips column again. It's been a couple years.

[gstallons]

i hope you use "silicone" brake fluid. It is not too cheap or too easy to get.

The main reasons are high boiling point (I hope you don't brake THAT hard) and conventional fluid is very hygroscopic. Hygroscopic means that it attracts and holds moisture. One less thing you want in the hydraulic system on your bike.

[dlaing]

Trapped air is not good and Rich Maund's advice is good, but I think the primary cause for short pad life is the pistons are sticking, and should be cleaned.

The bleeding process should loosen the pistons, but a good cleaning may be in order.

 

Also, Rich might want to check the bearing spacer. They are known for being too short, causing premature failure. 8000 miles is premature failure for a wheel bearing.

[Skeeve]

i hope you use "silicone" brake fluid. It is not too cheap or too easy to get.

The main reasons are high boiling point (I hope you don't brake THAT hard) and conventional fluid is very hygroscopic. Hygroscopic means that it attracts and holds moisture. One less thing you want in the hydraulic system on your bike.

 

Not cheap, not easy to get, and not easy to switch to: you have to replace all your brake lines & seals from stem to stern if they've ever seen DOT3, DOT4 or DOT 5.1? [DOT5 was the silicone, iirc. DOT 5.1 is the non-silicone higher spec of the poly-glycol stuff, if memory serves.]

 

At any rate, if your system has ever seen the regular glycol-based fluids, making the switch to silicone requires switching a replacement of any of the rubber components and complete cleaning of the system before installation of the silicone, as it reacts w/ the glycol to make some horrible sludge that tends to make your brakes not work when you suddenly need them most. Hence the introduction of the 5.1? fluid, which is just as hygroscopic as the older stuff, but at least is compatible.

[gstallons]

I'm glad to find that out about the incompatability of the two fluids!

[swinfurkon]

thanks for the MGNOC tip link, I am willing to try anything, so once I give the brakes a bleed using the right way up method, I will report back to this forum

[Chuck]

I would just like to add to this. I'd been having problems getting *all* the air out of Rosie's rear brake, even bleeding it with the nipple vertical. I had a good pedal, but when I was servicing her before a trip, I noticed the plastic cover on the caliper partially melted.

When I bought this bike the rotor was warped big time, and the brake pads were gone. I certainly didn't want this to happen again, so put everything new on it.

Obviously, I hadn't bled it well enough, but couldn't get any more air out of it. So... I hung a 20 lb machine vise from the brake lever over night. That did it. I've checked the rear caliper for heat several times now, and it is cold.

[LowRyter]

the solution for the green one was to pressure feed the fluid from the bleeder. be sure to catch the fluid from the reservoir.

[Chuck]

the solution for the green one was to pressure feed the fluid from the bleeder. be sure to catch the fluid from the reservoir.

 

I always do that. It apparently didn't get that last little bit of air out.