Question about brakes

[erchuero]

So I bought this part from gopowersports, Brake kit, and installed it on my kart. However, due to placement of the master cylinder, I needed longer front lines and shorter rear line, so I replaced them all and bled the system.

It is a dual plunger system. The front worked perfectly fine but the rear had no fluid pressure at all, and after disconnecting the line from the master cylinder and pumping the brakes there was no fluid coming out. So I bought a replacement master cylinder and installed it and now the rear works perfect but the front will not....

The front brakes bleed just fine, I am not getting any bubbles and plenty of fluid getting pushed through the system, enough pressure to push fluid into my catch can when bleeding, but the front calipers are not engaging at all... And nothing has changed, they worked perfectly fine before replacing the master cylinder.

Any ideas?

 

[Denny]

Are you bleeding the brakes correctly? Did you bench bleed the master before hooking up the lines to get all the air out? Those master cylinders move such little fluid you have to pump and bleed them slowly about a million times. You could make a pressure bleeder out of a new garden sprayer.

 

[erchuero]

Are you bleeding the brakes correctly? Did you bench bleed the master before hooking up the lines to get all the air out? Those master cylinders move such little fluid you have to pump and bleed them slowly about a million times. You could make a pressure bleeder out of a new garden sprayer.

So I did not bench bleed the master, but I did use a vacuum kit to get the lines full before resorting to the good old fashioned pumping brakes manually to bleed them.

I did find that one of my ****ty Chinese calipers had a stripped bleed nut, but that might have been from me bleeding for days, loosening and tightening it.

After replacing the caliper I did finally notice my problem, the bolt with the smooth end used to depress the plunger was too far in, so my guess is that wasn't allowing the plunger far enough back to let enough new fluid into the chamber... After backing it off I was able to build enough pressure.