Front hydraulic disk brake problem... By adamhoyer (Read 1,720 times)

[richardv]

Even my bicycles have disc brakes and I am glad of it. The bike in my avatar has a drum rear brake and it isn't very good at street speeds, like the disc on the Gold Wings were. There was much more control without a tendency to lock up.

[cyborg]

Getting back to the original post ,,, pulsing in the brakes is usually indicative of a warped disc,,, and it doesn't have to be a huge bend to be transmitted to the lever or bars,,, also I've seen and had myself a " soft spot " on the disc from a bad heat treatment ,,, it had a spot that wore quicker than the rest of the disc, which over time created a hollow spot that was thinner than the rest of the swept area which caused pulsing also,, I only had it happen on one bike but on several cars,,, but I still believe disc brakes are infinitely superior to drum which also had it's own set of problems as well,, like egg shape wear from material softness in areas so , uneven wear,,,

[Bashan]

Oct 28, 2014 20:00:32 GMT -6 adamhoyer said:

What if I bled my brakes wrong?

They would be mushy, not pulling. Either the caliper is off which is why I told you to lossen and squeeze the brake, or the wheel alignment is off.

[rks]

Say what you will, I still like drum brakes. My 66 LeMans weights 3500 pounds or more, stops fine with drums. During the 39 years that I drove commercial vehicles, I never found myself unable to stop in time...all had drum brakes. Those vehicle weighted 30,000+ pounds unloaded.....up to 80,000 pounds when loaded....and in my milk tanker days, a gross weight of 103,000 pounds was not uncommon.

As far as bikes I've owned, the Honda's, the BSA, and the R60/5....all heavier and faster than a scooter....all drums, never a problem

You may think that my 239 pound scooter needs 2 disc brakes to stop it safely...
And you may believe that my 563 pound BMW's need 3 disc's to stop 2 wheels.......but you will never convince me of it

[cyborg]

Oh don't get me wrong,,,,i like drums on certain machines ,,,and i actually like a disk front drum rear setup on a bike,,,i get better "feel" and less chance of me locking up the rear in a panic situation ,,,for me sometimes rear disc is too powerful for the application,,i never could figure out why the semi's and bigger stuff still are made with drum brakes,,i know they work ,,,must have something to do with the "fail on" air system,,,anyone know?

[jct842]

I could never figure why some scooter fanatics went to all the time and money of replacing a rear drum with a disc. All the back brake is for is to keep the back end from passing the front. And further that 150cc scooter does not have enough hp and speed to worry about. I had a rear disc on my old 150 and a drum would have worked every bit as good. I have a 180cc riva with both wheels stopping with drums and have no desire to install a disc on either axle. Even if some one gifted me with all the brand new parts I would need./

[adamhoyer]

I was looking all over for the problem and I'm going to bleed my brake line with a whole bottle of DOT3. I unscrewed the treetop thing holding my forks. and I could actually move one of my forks by twisting it to the left and the other one was stuck. Can the forks have anything to do with it?

[Bashan]

You mean one of the fork posts!!?? Yes! Get the wheels and fork lined up with one another and tighten the two bolts holding the post and don't ride it until you do!

[jct842]

If one fork doesn't do what the other does that's where the pulling is coming from. I can not see how a brake could cause pulling on a 2 wheel vehicle.

[cyborg]

Get everything lined up and tighten everything down to torque spec and like right now,, this is a very dangerous condition,, nothing should be loose on the front end,,

[adamhoyer]

Nothing was loose its that I loosened my front two bolts on the forks that hold them and I could twist the metal part on the fork to the left on the right fork if your looking at the front of the bike and the left fork would not  twist like the other one. I bled my brakes today and all I see is lots of air bubbles one each pump and I used a small can of dot3 and air bubbles are still coming out.

[adamhoyer]

Mine musted of warped within 30 miles? I went for a ride again and it still wobbles when I hit my front brake, so its got to be one of the forks are messed up or my alignment. How do I check my alignment and forks?

[jct842]

Some thing is loose. Are the head stock bearings snug and not flopping around? If you are stopped and put the front brake on then try to rock the scooter back and forth is there any movement? You don't even have to be sitting on it for that.