thanks for the help on my last question! (new one, front brakes sticking)

[ERM83]

The more I thought about my last question, the more I think "YOU ARE AN IDIOT, ERIC". Logically, it would've had to have been gunked-up float needles, given the symptoms. Thanks for the input on that anyway, everyone!! STTIIIIIILLL learning.

(This concerns the 1980 SG)
I rebuilt the front master cylinder, bled them like crazy, and they're still sticking! Also, that front lever is tight...like, only a slight bit of pull on it set them off, and to make the brake light switch go off, I had to pull hard enough to where it's a bit of an abrupt stop. I DO ride in pretty much all weather (besides snow), so do I maybe need to clean the calipers again??

did that about a year ago...not afraid of doing it again! as frustrated as I get sometimes, I LOVE this thing, and working on it.

P.S.- trying to start my (FIRST!) build on this thing (the SG), and want to have another whip, as I'll LOSE MY MIND if I don't have a rideable bike at hand. Someone 45 minutes away is selling a SWEET 1985 XJ700...FOR $500. Title is missing, but...I may capitalize on that. Gotta talk to the owner when I'm close to having that disposable cash. All it needs is a starter. Supposedly runs fine otherwise. Need to find out the mileage as well.

P.S.S.- which engine is stronger...the 79'SF, or the 80'SG?? I've used parts from the sf for the sg, so that it is actually a complete, running bike. however, the sf needs a new head (valves / springs, etc are good).

You all are THE. BEST. THANK YOU for all the help over this past year and a half!!

Eric

[jetmechmarty]

When the brakes are stuck, loosen the banjo bolt at the master cylinder. If they release, the master cylinder is at fault. If they remain stuck, it's a caliper.

One of those Maxims had 11:1 compression and a five valve head. I thought it was an XJ700. ?? Do some research. Try XJBikes.com.

Seat of the pants, I don't think you'll know the difference between a '79 or '80 XS1100.

[Geezer]

I've also seen corrosion in the caliper causing the pistons to stick and it can be worse when warm. Take the caliper apart and clean out the grove where the seal goes.

Tony

[Barbarosa]

Make sure caliper is centered if special forks.

[brcree]

Sticky brakes.

My 81 S front brake will stick if I don't ride for a long time. The caliper piston has a o-ring in a slot and it gets gummed up. I guess with the brakes not being used and getting hot with use, junk builds up in this area. I use a grease gun to pop out the piston, easy, quick, and grease is cheep.

[Geezer]

I would avoid letting grease touch the inside of a caliper. The seals will swell in contact with mineral based lubes.

It's better to used compressed air to pop the piston out of a caliper. I put a piece of wood in place of the brake pads to cushion the piston as it comes out.

Only use silicon or plant based lubes on rubber break parts. The best I've found is RCBS case sizing lube. It's basically industrial thickness KY lube...

Tony

[brcree]

Good info Geez....I failed to mention, my piston didn't budge using air. Will use your suggestion from now on.

[rangerguy302]

Hey erm83, when your break hung up did it cause the forks to jump back and forth?

[rangerguy302]

Hey erm83, when your break hung up did it cause the forks to jump back and forth? I think min might be doing that, anything after 80mph and it shakes hard. I can lean over and watch the front end jump back and forth

[Geezer]

Hey erm83, when your break hung up did it cause the forks to jump back and forth? I think min might be doing that, anything after 80mph and it shakes hard. I can lean over and watch the front end jump back and forth

That sounds like an out of balance front wheel and worn out fork bushings.

Geezer

[motoman]

Hey erm83, when your break hung up did it cause the forks to jump back and forth? I think min might be doing that, anything after 80mph and it shakes hard. I can lean over and watch the front end jump back and forth

If so, do the front rotors get hot with no brake applied? If so, beside just a rotor being ever so slightly warped, the front brake system hydraulics etc. need going thru and rebuilt. Just pay attention when attaching rotors back on and installing wheel as there is an alignment procedure for those tapered front brake pads and assembly.

[MPittma100]

Check valve

If you still have the problem after building calipers and master cylinder, you likely did not get the master cylinder clean enough. Brake systems in all automotive brakes have a residual check valve. This can be an actual valve or a very small orifice in the master cylinder. May have to take a second look at your m/c. Yamaha used an orifice in the m/c.

[Schming]

THIS ^^^^

Also if your brake lines are original (38 yrs. old) they should be replaced as they deteriorate from the inside