Brakes Wont squeeze!!

[Santan Kart]

I have a yerf with the rear disc Brake and have tried everything to get it to stop my kart with no luck. The pistons are freely moving in the caliper, I've bled the lines a million times it seems, adjusted the plunger on the master, and it still does not squueze the disc enough to stop the kart. Any suggestions? i guessing there is a leak in the Master somewhere, and it is not building the pressure it use to. Do they make a rebuild kit for them?

 

[machinist@large]

I have a yerf with the rear disc Brake and have tried everything to get it to stop my kart with no luck. The pistons are freely moving in the caliper, I've bled the lines a million times it seems, adjusted the plunger on the master, and it still does not squueze the disc enough to stop the kart. Any suggestions? i guessing there is a leak in the Master somewhere, and it is not building the pressure it use to. Do they make a rebuild kit for them?

Whats the condition of the pads? Could be they are just worn out.

 

[landuse]

Have you got the correct brake disc for the brakes that you have. Some discs are thinner than others

 

[ML-TOYS]

Have you got the correct brake disc for the brakes that you have. Some discs are thinner than others

yep i discovered that the hard way on one kart.

as mentioned check the pad thickness and disk thickness.

 

[anderkart]

What model is your yerf kart?

If you have a nice firm brake pedal feel, you could try using some sand paper to de-glaze your rotor and brake pads, so they can get a better grip to each other. If your pads are worn thin, replacing them or sometimes just shimming between the calipers piston and back of the pads might help too.

 

[Santan Kart]

Brake pads are good with very little wear on them, I am curious to know what the disc thickness should be? Going to try to de-glaze and see if that helps. Otherwise I'm looking to replace the master, anyone got an extra one lying around?

 

[deloreanaka8]

Also, is the cylinder sealed properly? Maybe you could check that too.

 

[stratguy44]

Does this type of caliper slide? I had one that stuck and wouldn't slide so only the onboard pads would contact rotor so caliper wouldn't squeeze the pads against rotor

 

[anderkart]

Brake pads are good with very little wear on them, I am curious to know what the disc thickness should be? Going to try to de-glaze and see if that helps. Otherwise I'm looking to replace the master, anyone got an extra one lying around?

There were several different Yerfdog models made over the years using diferent brake componets. If your not sure which model you have, you'd need to post pics of it, or find a pic of one exactly like yours before we could give better advice.

Heres a link to lots of yerf pics:--> http://www.google.com/search?q=yerf...qw2wX0jIDwBQ&ved=0CDYQ_AUoAQ&biw=1024&bih=556
If you find your model, you can usualy click on that pic to see if theres any info included.

 

[Santan Kart]

Here are some pics of the braking system

 

[anderkart]

Does your Yerfdog have any model# stickers or labeling anywhere?

Your Rotor looks glazed/polished-smooth. Did you try sanding it and your brake pads so they can get a better grip to each other yet? (that might be all you need to do)

The outer portion of your rotor most-likely started out being the same thickness as its center section.

If your master cylinder isnt leaking, replacing it with the exact same type probably wont improve your braking power at all, however it probably would help if you installed a different master cylinder with a larger bore-size, and maybe improved the linkage design to apply more leverage...

Your master cylinder/brake line connection is the Banjo-type fitting, many motorcycle master cylinder's use the same type of connection. If you could find one from a 750cc or larger bike that fit with minimal mods, you'd probably end up with better braking power.

 

[spyder1968]

from the pics it looks as though you have a fairly large caliper. the master cylinder may not have enough capacity for it.
does the brake pedal go all the way down? if so, it the linkage giving you "maximum" stroke on the master cylinder?