Hello,

No matter what I do to the front drum brakes they will not grab or slow down the machine. I've pulled them apart, cleaned everything, tightened up the cables and the lever gets tight and I can see them expand, but no real stopping power. Any ideas? Is this a cable lube issue? It is an older 110cc and I am looking to sell it but I don't want to put the next guys kid in jeopardy. Short of removing them and selling with a back break only I am not sure what more to do? I don't plan on replacing the assemblies as this quad will go for like $300 or so....

Any ideas will be greatly appreciated.

 

Did you clean the shoes and drums with brake cleaner, and rough both shoe and drum surfaces with coarse Emery? The pivots for the cams must be free, and the angle the cables make with the levers on the cams is important, as near to 90 degrees when brakes are on, as possible. Cables should be lubricated too.

 

I used an green scotchbrite pad on the pads and the drum, used brake cleaner and the brakes seemed to actuate properly but I did not lube the cable. Sorry but what are the "pivots for the cam"? The levers on the bike never moved and the brake itself locks into a tab on the frame near the wheel so the cable is ran like it had always been. I can't install the brake upside down or anything so I don't think I changed the angle of the cable at all but I will check it out to make sure and I have a cable lube deal on order, will be here Thursday. I have always had issues with these from drum brakes on these quads so it is frustrating for sure.

Thank you for the reply Merryman.

 

The cam lifts the shoes onto the drum, and turns in the backplate, so the cam must be free to turn. The most common fault with drum brakes is that cam sticking in the backplate. This cam has splines for the lever that turns it. The lever must make the correct angle to the cable, circa 90 degrees. As the cable stretches and shoes wear, this alters, and the lever can be fitted on a different spline to compensate. The cables are then adjusted to suit the new position. Often there isn't enough adjustment to make the correct angle but, as near as possible, can make a big difference to the braking.

 

Merryman, THAT is the kind of info I needed, makes perfect sense. Thank you for explaining and I will tear back into these and let you know what happens.

I really appreciate the help.

DRN

 

Well I continue to fail on the brakes. Lubed the cables, scuffed the rims and shoes, readjusted the cam/spline, grabs but doesn't grab enough to slow it down. Question now is, where do I start the replacement parts? Cables? Pads? Drums?

Thoughts anyone?

DRN

 

If the handlebar lever springs back when you release it, the cables are probably OK, so I would try new shoes. There are stories of very poor quality linings on Chinese shoes, so a change to decent quality shoes may do the trick.

 

Thanks Merryman. I will try that and report back.

I appreciate your time and advice.

DRN

 

New front shoes helped, rear brake no dice now but that has been out for a while, I figured pads. Pads are good, purged a bunch of fluid through and still nothing.

I am having trouble figuring out if the brake pedal is bent and hitting the footrest or if the master cylinder is bad, it is an older quad that the kids ran into the ground. Ran out of time to check into it but anything to consider when checking that?

 

Hydraulic disc brakes don't usually have much pedal travel and the most common problem if they do, is air in the pipe. Pipe runs are often badly designed on quads and air will find a high spot and sit there, refusing to bleed out as fluid flows past, under the bubble.