Auto vs mc master cylinder

[Chappy KC]

I am one of many who is dealing with rear brake issues here and I was just wondering if a small automobile MC would work better for the rear disk brakes? It seems to have more volume to push out to the calipers. Any input?

[jfreelan]

what trike kit do U have? I think what you have is probability ok, is pedal soft, what are the symptoms U R experiencing?

[Chappy KC]

I have the Motor Trike kit on the back of a Kawasaki Voyager. When I bought it the brake was spongy and had to be pumped to get anything at all. Dealer just shrugged me off. I thought maybe that was normal. I called Motor Trike and they said they needed bleeding. Ride it for 1000 miles and take it in for service and have the dealer bleed them. I did that at 1600 miles. I had no rear brakes at that time. Dealer did some bleeding but still the brakes would not stop the trike. They said they would call Motor Trike and see what they recommended and they would get back with me. That never happened. The last time I had it I could pump the brake and push it to the floor boards with no effect. Totally useless.

[jfreelan]

sounds to me like U have a leak in the rear brakes, bleed till the pedal is hard, making sure the fluid reservoir is been kept full while bleeding. if U can't get a hard pedal you have a leak.

[Chappy KC]

A leak sounds reasonable but the dealer has not spotted it. There may be air or contamination in the lines too. But the dealer has not figured that out yet. Since it is on warranty, I would just as soon let the dealer mess with it. If I file a lemon law claim maybe Motor Trike will become a little pro active? Since it is in the shop waiting for unrelated repairs, I will see how the brakes work when I get it back this time.

[FuzzyWuzHe]

It could also still be air in the system ... I was working on a friends Desoto, and I finally had to get a power bleeder that sucks fluid out all the bleed ports at once, puts it into a reservoir and pumps it back to the master cylinder ... took about a half hour of that to get all the little bubbles out.

If you still have a spongy pedal and no fluid coming out on the ground or anywhere else visible (brake fluid is really fluid ... if it's leaking odds are good you'll see it, if the level in the master cylinder isn't dropping, no leak), it almost has to be air. Could be a bad master cylinder too, but from your symptoms, I think it's air. Sounds like your dealer is not willing or able to get all the air out.