Need advise.

[triker1]

I have a Harley Ultra Classic w/ Mystery Design trike kit. Having rear break problem. Sometimes I have good firm brake and other time the peddle goes to the floor. There are no leaks. Have installed two new master cylinders, took the caliper apart and cleaned it. It has a steel braided brake line. Have bled brake several times. Nothing works. Mystery Designs says call caliper company which is Wilwood. They said "Very interesting". Would like some real advise.

 

[Rsw]

Does the brake peddle come back after you pump it a couple times? Or how do you get the brake peddle back?

 

[eagle1]

you shouls have a adjustment on the master cylinder where it connects to the
brake pedal. sometimes if you don't allow it to retract enough the cylinder won't get enough b/fluid for good brakeing. also when i bleed brakes i buy 6' of tubeing and on the rear; use a vacuum "T" and put it over the bleed valves & hold the open end
over the resivor, then slowly bleed, bleed ,bleed till i know all the air is gone.
do you use SPEEDBLEEDERS? they have a check valve in they so air won't enter
the caliper as you bleed.
just a suggestion you probably already know.

 

[triker1]

Yes, you can pump the peddle a couple of times and you have brakes but you never know how long they will last. I have went several miles and sometimes only a few blocks.

 

[Rsw]

If the master cylinder is lower then your calipers, you need to have a residual valve. This keeps the brake fluid from draining back into the master cylinder. Do you have one? If you don't, your calipers are taking a couple pumps to get pushed back out to contact the rotor.

Something like this.
http://www.appletreeauto.com/product.php?productid=18252&page=1

 

[triker1]

No I don't have one. That could be the problem. Thanks

 

[Tripacer1]

have you had any luck figuring this out
im having about the same issue but i do Have a residuale Valve but it is clear back bye the back of the bike
might put one in the line closer to the M/C

let us know how you come out with your issues

 

[Rsw]

have you had any luck figuring this out
im having about the same issue but i do Have a residuale Valve but it is clear back bye the back of the bike
might put one in the line closer to the M/C

let us know how you come out with your issues

It shouldn't make a difference where the residuale valve is, as long as it is before it tee's to each rear wheel.

 

[Tripacer1]

its just before the Y in the hoses going to the Calipers

im thinking i might still have air in the system
each caliper has two bleeders i have been using the top one
might try Bleeding Both and see what happens

im also going to check the Pedal and make sure that its not stopping before the pedal is all the way back
i know it has a different pedal than OEM

 

[triker1]

Discovered the problem. It wasn't the brake after all. Part of the differentual houseing fits into enter axle bearings. This part broke off, the bearings were shot. This allowed the rotor to move back and forth about an 1/8 inch. When the rotor was in the correct position I had brakes, when it moved over, the pads would not reach the rotor until pumped. Mystery Designs are sending me new parts however no one has figured out what caused this.