Brake Question

[rehler]

I have Hagar hydraulic disk brakes with the standard 5/8" single master cylinder. When I push on it the brakes activate, but if I continue to push (like during prerotation) it starts to slowly go down farther until it finally hits bottom. Since there are no leaks I assume that there is a problem with the master cylinder.

Is this a common problem with Hagar brakes - I just need to replace the master cylinder?

Or

Is this the same for all Hagar brakes - I should buy another brand/type of brake system (several have been suggested)?

[GyroRon]

Sounds like you need to do some more bleeding in your system to me.

[rehler]

Ron,

I've bled and bled several times. Do you think it is air in the system? Could air cause the master culinder to work, but then if pressure is maintained slowly move down to the bottom?

[scottessex]

sound like your master cyl is leaking down internaly.

Usually air will feel spongy, if you pump it a few times it will stiffen up and the pedal won't go down as far.

[Vance]

Ken, if it was a motorcycle brake system and it did that, without leaking externaly, it would be fluid leaking past the mastercylinder cylinder piston cup. This could be either because of roughness in the mastercylinder bore or something wrong with the cup on the fluid side of the mastercylinder piston. Even if it is common to the design you should be able to find a way to repair it. All it takes to make it work is a good seal and a smooth round bore. If the problem is anywhere else in the system it will leak externaly or be spongy from the outset. Hydraulics are just a way of transfering motion, keep it simple. Thank you, Vance

[GyroRon]

Ken I have had a heck of a time trying to bleed Hegar brakes on the machines I have owned that had them. First off they use ATF not brake fluid, but I think you already knew that. I ended up using a hand held oil pumper to pump the fluid in from the master cylinder and opening the bleeders at the brakes till I got a good solid lever, took a while and was very messy. Might be something else that is the problem though.

[Rick Whittridge]

Ken, Hegar makes two differant brakes.Are you using the POSI-STOP or the DISC BRAKE SETUP? What mcyl do you have?

Sorry Ken i see you have the disc brakes. If you don`t see any fluid expelled from the system then you must have air somewhere.Did you use the oil can bleeder that comes with the brakes?