Front brakes 1981 GS850G

[ardbeglily]

thanks

Thanks coolksprt, mine is a little different, it is a square 5/8 with four screws on the reservoir lid. Does anyone know how to get the reservoir off so that I can get to the seal underneath. I currently have fluid and no air from the right side bleeder and fluid and some air from the left side. The lever is still very soft and comes back to the bar.

[jimfj]

I just rebuilt a master cylinder on my 1100G. I had somewhat of the same problem. First of all make sure your banjo connections all have the proper washers attached. Basically a washer needs to be on each side of the banjo fitting.

Even if you have some air in the lines the pistons should move in the calipers. If they don't, its M/C related and start there, working your way down.

My problem was that I kept getting a bubble now and then but the lever would never firm up.

The solution, after much aggrevation, was to remove one caliper at a time and pump the lever so the pads were too close together to go back over the rotor. I then took a screwdriver and gently pushed the pads apart enough to go back over the rotor, no more than needed. Put the caliper bolts back in and do the same for the other side. I went from a lever that pulled almost halfway to the bar before any friction, to a lever that takes one finger to make the bike stop.

It sounds like you are having some of the same issues but you shouldn't have a drip or leak. i know its frustrating but go through it methodically and you'll find the culprit.

Jim

[tkent02]

I wrapped all the banjos and bleeders with Teflon.


I have tied the lever to the grip for a few hours but on my return all the banjoes are leaking.

Take the teflon tape out of the banjos, they seal by the crush washers. If it still leaks, get new crush washers.

The teflon is only used on the bleeders so they don't suck in air through the threads while they are loosened for bleeding with the mighty vac.

It seems you may have other issues also, were the piston bores smooth and clean?

Do what jimfl says above.

[Nessism]

My problem was that I kept getting a bubble now and then but the lever would never firm up.

The solution, after much aggrevation, was to remove one caliper at a time and pump the lever so the pads were too close together to go back over the rotor. I then took a screwdriver and gently pushed the pads apart enough to go back over the rotor, no more than needed. Put the caliper bolts back in and do the same for the other side.

I don’t want this to come across as picking on you Jim but this repair scares me. First of all, the reason the calipers are binding up is because they are full of crud. Forcing the pistons back using a screwdriver pushes the crud off the immediate working surfaces but the crud is still in the system waiting to foul the pistons again. The proper repair is to remove the caliper pistons and clean out all the sludge, followed by reassembly and greasing the sliding pins. Also, if your bike still has the rubber brake lines they should go in the trash; replace with new OE lines or the ever popular Teflon/stainless type. Brakes don’t require much maintenance but when they do it pays to do it right.