2012 RSV braking issue

[mcgwire723]

We had a group ride yesterday in the gorgeous Ozarks. I was on a long steep grade with multiple 180 degree switchbacks. At the last one I stepped on my rear brake pedal and it went to the floorboard with no resistance at all. About 10 miles later and the rest of the ride it felt normal. Prior to this one event it worked normal also.

 

Looking for any input as to the reason it would do that.

 

Thanks

[slowrollwv]

If you were long hill with a lot of switch backs and used your rear brake a lot to slow down . They got hot and lost there ability to slow or stop you. I am in WV with a lot of mountains, when I start down and I think or know it is steep and twisty I use 3 RD gear and let the motor hold me back and the brakes do not get hot.

[mcgwire723]

That's what I though, just making sure, I was in second gear and just thought it was weird to only do it once.

[XV1100SE]

I would also consider that with a 2012, have you changed your brake fluid? Supposed to change brake/clutch fluids every 2 years. What colour is your brake fluids (rear and front) ?

 

Also...what is the mileage on your bike? Pads worn ? (unlikely pads but more likely your brake fluid).

 

Hot pads would still give you pedal pressure but not grip.

[mcgwire723]

fluid has not been changed, The clutch fluid in really dark, and the front fluid is darker than normal, I will change them.

 

Mileage is 13000, rear pads were replaced 4000 miles ago, they were wearing funny, inside looked new, outside was almost gone.

Edited August 3, 2015 by mcgwire723

[XV1100SE]

Dark fluid means there is moisture in with the fluid. This is "normal" over time and one of the reasons it is recommended to change the fluids every 2 years.

 

Basically...moisture (old fluid) changes the boiling point of the fluid and heavy use could "boil" the fluids. This reduces the hydrolic pressure.

 

Okay....so probably not the technical and 100% accurate account....but a laymans description.

[XV1100SE]

fluid has not been changed, The clutch fluid in really dark, and the front fluid is darker than normal, I will change them.

 

Mileage is 13000, rear pads were replaced 4000 miles ago, they were wearing funny, inside looked new, outside was almost gone.

 

Just to make sure you know...the reservoir on the handle bars are for clutch and FRONT brake. The rear brake reservoir is near the air intake on the right side of the bike. Make sure you do all three.

 

As a suggestion... if you ran in really hot weather and the engine temp was up for an extended amount of time, consider changing your coolant if it hasn't been changed yet.

[mcgwire723]

I completely understand, sounds like I will be doing a maintenance day. I was planning on doing all 3, I will also do the coolant.

[slowrollwv]

As for the rear pads wearing funny. They all do . Best thing to do is switch the pads from side to side. I do mine about every 2,000 miles. That way I know when I have to change brakes. Those rotors get expensive to replace for a brake shoe.

[MikeWa]

Hmmm. With over heated brakes the pedal usually gets hard. The brake won't slow you even if you stand on the pedal.

Going all the way down with no resistance is something else. Fluid is bypassing in the master cylinder or air is in the system or some such thing. Moisture may have boiled and turned to gas. I suppose the fluid and master cylinder could have gotten hot enough to distort and allow fluid past the piston. But that is highly unlikely. I would change the fluid and carefully bleed the system. If it happens after that I would change the master cylinder.

 

Mike

[camos]

.... air is in the system or some such thing. Moisture may have boiled and turned to gas.

 

Mike

Boiling moisture from the oil could act just like air in the system. Particularly, if it collects at or near the master cylinder it would most likely allow the pedal to fully compress with little or no resistance. Cooling off might allow the moisture to be reabsorbed and give you back some pedal pressure.

 

Bleeding the system until clear fluid comes out the valve is the solution.

 

While you are at it, remove the pads for inspection and swap sides if there is uneven wear. With the pads removed "gently" apply brakes to extend the pistons out a little farther than they were with the worn pads. Not so far that the piston is pushed out of the cylinder.

 

While doing this watch for a piston that is moving faster than the others. This indicates the slow ones are dirty and somewhat crudded up. Use a vicegrip, clamp or the pads with a wrench handle between them to stop any fast piston and allow the slow piston to catch up. About 1/4 inch more than the starting position should be enough. Clean the pistons and the area surrounding them with brake cleaner and an old toothbrush. Push the pistons back in and apply brakes gently again. All pistons should move at about the same rate. Air in the system could affect the movement of a piston somewhat but it is quite obvious whether they are moving easily.

 

If the pads are being replaced at this time, put the new ones in then bleed the system. If the pads do not need to be replaced then bleed the system before cleaning the pistons.

[mcgwire723]

Thanks for all the help. I will be doing a full brake fluid, clutch fluid, and Coolant change tomorrow, I will also check the pistons.

[Rick Butler]

Chuck has it right,

 

If you get a set of oem pads too hot they will fad.... bad. But my question is WHY are you using the rear brake to scrub off speed......that's what your front brakes are for, where they load the front tire and give you a bigger contact patch. You get 70% of your total stopping power from the front brakes.

 

Hope this helps,

 

Rick

 

If you were long hill with a lot of switch backs and used your rear brake a lot to slow down . They got hot and lost there ability to slow or stop you. I am in WV with a lot of mountains, when I start down and I think or know it is steep and twisty I use 3 RD gear and let the motor hold me back and the brakes do not get hot.

[djh3]

A couple yaers back when I first got the RSV, we were in NC. I had not ever read about the brake fluid issues. Well after dang near running some JA in Range Rover we,were following down mountain roads and my back brake went to the floor. The dummy was riding brakes terrible. I put distance between us to start, and started using the motor way befor they went south. Short story is they went to the floor, I down shifted to 1st and used as much fronts as I could and still be safe. Got to a state park and pulled off. 10 min or so later they felt fine and we continued. Full flush happened on all 3 hydro systems when I got home. Since then I think the system has been flushed every year.

[mcgwire723]

Guys,

 

Thanks for all the help. I changed all the fluids out and it feels like a new bike again..... its amazing how much "fade" the old fluid has, everything is firm and works great now.

 

Thanks again