GS450L, Front brake pads too tight on rotor.

[Dcboys81]

I just bought new brake pads for my front disc brakes. The pads are made for my bike. 1985 GS450L. I also replaced the back brakes which are fine. I pushed the piston back in as much as i could. unscrewed the top where you put the brake fluid in so the piston could get back in. I put my new pads on, and the piston is all the way back inside. I can not spin the wheel freely without it stopping right away. And when riding all the brake does is squeal and squeak. Is there a way to loosen these pads anymore?

[almarconi]

You may want to try and loosen the bolts holding the caliper to their bracket. I recently replaced the front wheel on my bike and had a similar problem. The front wheel would not spin freely. I guess I over torqued the caliper bolts when I put everything back together. Once I loosened the bolts, I was able to spin the wheel. Make sure the caliper is aligned with the rotor and not cocked to one side.

[psyguy]

Make sure the caliper is aligned with the rotor and not cocked to one side.

as above + make sure that the caliper slide pins move freely (best take them off, clean, and lubricate)

other than that - you got the wrong pads or have wrong caliper/rotor/mounting parts

[Dcboys81]

The package the pads came in clearly states 85-88 GS450L. I got them from my local motorcycle dealership also. So I dont think the pads are the wrong size. Plus people keep tellin me the piston isnt going back in enough but when i took the pads off yesterday the piston was in as much as it could go so I dont think thats the issue either. Just a tab bit too tight!

[almarconi]

If you can't easily spin your front wheel, I would not ride the bike. You could damage the bearings, overheat your rotor(s) and worse injure yourself and others. Try using a c-clamp to push the piston into the caliper. Open the bleed valve so the fluid is not pushed upstream.

[Dcboys81]

I tried again. Squeezed the piston in a little more by hand. Got quite a bit more fluid to come out, and the caliper and pads slid on easier this time then the first. Before squeezing the brake, there was plenty of room between the pads and rotor. the wheel spun at will. After squeezing the brake to become firm the brakes seem to be up against the rotor again and I can spin the front wheel but it stops a second later because the friction on the pads and rotor. Seems as if the piston isn't going back as much as it should. While riding I get this metallic squeak once in awhile. Obviously the pads and rotor rubbing. But the bike will coast a bit, the brakes aren't dragging extremely bad. How do I go about cleaning or clearing the master cyclinder incase its clogged a bit and not allowing the piston back in?

[Nessism]

If the piston does not move smoothly then it's time to pull the caliper apart and clean out all the corrosion and sludge. I recommend changing out the brake line at the same time and cleaning out the maser cylinder as well. Brakes are nothing to monkey around with.

[chef1366]

Use a c-clamp to push in the piston. Don't open the bleeder valve or you will introduce air into the system.

[psyguy]

Seems as if the piston isn't going back as much as it should. While riding I get this metallic squeak once in awhile. Obviously the pads and rotor rubbing. But the bike will coast a bit, the brakes aren't dragging extremely bad. How do I go about cleaning or clearing the master cyclinder incase its clogged a bit and not allowing the piston back in?

caliper piston not retracting is more likely due to the caliper/piston assembly fault than due to the master cylinder, so i would start by taking apart the caliper.
but as nessism said, best to do it all at once. i recently finished doing up my brakes with new pistons/seals/ss lines, and the improvement is remarkable.

[almarconi]

Don't open the bleeder valve or you will introduce air into the system.

If you don't open the bleeder valve, all the rust and crap will be forced upstream into the MC. If you try this on a car with ABS brakes you run the risk of clogging the ABS pump. Introducing air into the system has never been a problem, just close the bleeder valve after you compress the piston.

[Dcboys81]

I opened the caliper up, cleaned everything inside. Put a little grease on the piston, but the piston is actually pretty darn clean. I changed out the brake fluid. It did need it, did it just because. Difference in color was night and day so i think it was due. But then the brake was still dragging a bit when we would lift the front tire and try to spin it. I ever so slightly started loosening the caliper bolts to the point it was tight but I could not turn it with my fingers, and that seems to have been a big problem. Now the noise is pretty much gone while riding but spurts up here and there but not for long. The bolts just might have been too tight for having new pads and caused a problem. Once the pads wear in a tad bit more I think the problem will be gone. Thanks for everyones help!

[almarconi]

Put a little grease on the piston

When you get a chance, you should remove the piston and clean off the grease. The only substance that should be used when assembling brake components is clean brake fluid.

Grease can be used on the back of the pads (shims) and the caliper pins.

[Dcboys81]

I did put the grease on the back of the pad. By putting it on the piston I meant the end of the piston that pushed the back of my brake pads. The piston itself was clean so I didn't touch anything when I extended it out.

When you get a chance, you should remove the piston and clean off the grease. The only substance that should be used when assembling brake components is clean brake fluid.

Grease can be used on the back of the pads (shims) and the caliper pins.