Front brakes won't build suffecient pressure!

[DieFeuer]

Hello guys!

I am working on this kart with two brake calipers on the front wheels. The master cylinder is located on the steering wheel.

I've tried both air bleed methods. One of them was the gravity method, and the other one was the "pump pressure method. Pump three times, hold it, and then unscrew the air valve. The oil seems to be without air, but i suspect that i have trapped air in my mastercylinder.

How can i be sure to get it all out?

 

[ML-TOYS]

Got a pic of master and calipers aling with disks

 

[DieFeuer]

https://postimg.org/image/r770fezul/

https://postimg.org/image/bkfr21m2l/

The best i could find!

 

[OzFab]

First things first, gravity bleeding is pointless on that system because gravity lets the air move to the highest point... being the master cylinder; by gravity bleeding you, most likely, let more air into the system than you removed...

It may not be that the master cylinder needs bleeding, the air is simply sitting in the top of the hoses attached to it; it'll take a lot more than three pumps to move it through to the caliper...

To answer your question, bleeding a master cylinder involves removing the hoses/pipes &, with a pan of some description correctly positioned, pump the master until you see strong streams of fluid from all exits; this can be done one at a time but, for best results, do them together; reattach hoses & pump slowly about 15-20 times then pressure bleed the caliper...

Note that, because the caliper has no air in it now, it will take some time to move all the air in the hoses through to the caliper; you may need to refill the reservoir 2 or 3 times during the process...

 

[DieFeuer]

The highest point is the reservoir. A tube is going from the master cylinder up in the reservoir.

If i removed the hose going from the cylinder to the two calipers, wouldn't i let in air, the moment i installed the hose again? In fact, i tried this. Also to see if it was able to develop pressure.

 

[OzFab]

The highest point is the reservoir. A tube is going from the master cylinder up in the reservoir.

Ok, allow me to finish the sentence:

"The master cylinder is the highest point of the PRESSURISED system..."

The reservoir is simply a feed; the only part it plays on the pressurised system is to supply fluid...

If i removed the hose going from the cylinder to the two calipers, wouldn't i let in air, the moment i installed the hose again? In fact, i tried this. Also to see if it was able to develop pressure.

That will allow air into the hoses (I thought I mentioned that), hence the need to pump the pedal, seemingly, excessively prior to bleeding & continue bleeding until all the fluid has passed through the system (I thought I mentioned that too)...

 

[ML-TOYS]

I actually use this. Even on my brake jobs on cars. I get i nice high pedal every time. Air out fluid in.