Front Caliper Problem

[djg42]

Thanks, will I have to you bleed the brakes after i clean it out?

Unless you have already done it I'd remove the caliper and pull the piston out to clean all the grunge out from inside the caliper. Brake fluid is hydroscopic which means it holds water, and old brake fluid jells up and coagulates with age so the best thing to do is make sure the system is properly cleaned out from time to time. Also, replace your rubber brake line if you still have the original. Suzuki calls for periodic line replacement so if your bike has the original you are about 28 years overdue.

[almarconi]

Thanks, will I have to you bleed the brakes after i clean it out?

Yes you will.

[djg42]

now that im looking closer at the brakes, the front brake lever feels weird, i can pull it all the way to the handlebar without much effort, is this "spongy"? Does it mean theres air in the brake line? Thanks

[gggGary]

You have the advice, your spongy lever confirms it, it is overhaul time, no buts, ifs, or maybes just do it and be glad (safe). As mentioned; remove, clean, replace parts as needed, the master cylinder, caliper(s) and caliper slide pins. Seriously consider new hoses while you are there. Front brakes that work great, priceless. If this is beyond your comfort level find someone who can do it for you.

[djg42]

i think ill replace the brake line while am at it. Is their a specific type/brand thats better to use? Thanks,
DG

[Don-lo]

I agree that a clean caliper assembly with fresh fluid and good lines are essential, but since this problem surfaced after removing the forks and wheel it is probably a problem of slightly bent forks, axle and alignment. The discs are essentially perfect "T"s coming out from the wheel, and forks need to track true to align. A small deviation will load one end of the brake pad, and thus one side of the piston, which does not easily move it. Leaving the caliper bolts less than tight is a way to compensate for this slight deviation. You can usually align the forks if the bend is not too bad. First, loosen the fender and any fork brace. Then, with the front end slightly in the air, loosen the top fork-holding bolts on ONE fork. This should allow you to spin the fork top. Look down the fork as you spin it and note if the wheel and forks are moving side to side and front to back (and probably binding as they go). I would choose the middle/ back location to set the forks. Make sure the fork top goes up to where you set them, tighten the fork-holding bolts, and then repeat this procedure for the other fork. Badly bent forks should be replaced, of course, and they will usually be accompanied by a bent lower triple clamp. Fork alignment then needs to be done (pumping them and retightening).

A bent front axle cannot be overlooked either.

[DanTheMan]

Here's another possibility for the OP. Check your axle bolt on the front wheel, Loosen it, see if the wheel spins freely. Tighten it just to the point where the brake starts to drag. Back it off slightly, check to ensure you have no axial play (with the bike on the centre stand, try to wiggle the wheel back and forth in the forks). If there's no axial play, your axle nut is tight enough, tighten the axle clamps and put a new cotter pin through the nut. Sometimes in the zeal to make sure everything is tight so there isn't a safety issue it can be tightened to tightly causing the calipers to drag on the discs. I think the manual calls this centering the wheel. If it's too loose you'll get wobble out of the front end.

[djg42]

Thanks! im gonna go out to the garage and try it out now.
If i upgrade to steel braided brake lines, does it improve performance or just durability? thanks-

[DanTheMan]

Thanks! im gonna go out to the garage and try it out now.
If i upgrade to steel braided brake lines, does it improve performance or just durability? thanks-

They will do both, and you get the added bonus that they look pretty.

[chef1366]

I've never heard of not tightening down the caliper.
Push both pistons in with a c-clamp and see if that helps.

[Dave_17954]

I was reading the post here and I just replaced my fork seals and front brakes on my 81 gs650 this past week. According to my service manual it says the tightening torque for the "caliper mounting bolts" is 18.0-29.0 ft lbs. and the "caliper axle bolts" is 29.0-40.0 ft lbs.. I'm assuming the caliper axle bolts is the ones that everyones talking about here. I torqued mine to spec and I didn't use any loctite on them. It also says to use the suzuki silicone grease on the "caliper axles" I used "syl-glide" which is very good stuff. I got mine all back together and everything is working good. I noticed the axle bolts got more torque than the actual mounting bolts.... mounting bolts being the ones used to mount the caliper to the fork. Dont know if this would pertain to the 850 or not but thought I'd throw it out there.

[djg42]

thanks everybody for the great advice. I think i just had overtightened some bolts, i took the wheel off and re-assembled it and it spins free now. I also cleaned out the calipers and bled the brakes-everything seems to work nicely now. Thanks again everyone!

[Nessism]

I was reading the post here and I just replaced my fork seals and front brakes on my 81 gs650 this past week. According to my service manual it says the tightening torque for the "caliper mounting bolts" is 18.0-29.0 ft lbs. and the "caliper axle bolts" is 29.0-40.0 ft lbs.. I'm assuming the caliper axle bolts is the ones that everyones talking about here. I torqued mine to spec and I didn't use any loctite on them. It also says to use the suzuki silicone grease on the "caliper axles" I used "syl-glide" which is very good stuff. I got mine all back together and everything is working good. I noticed the axle bolts got more torque than the actual mounting bolts.... mounting bolts being the ones used to mount the caliper to the fork. Dont know if this would pertain to the 850 or not but thought I'd throw it out there.

That Sli-Glide stuff pretty good for lubricating rubber parts and such but real caliper grease is thicker and better for lubricating things like those sliding pins? http://shop.advanceautoparts.com/web...sku=12027858-P

[1948man]

Would Moly Paste work for lubing the caliper axles? I'm in the middle of this cleanup now. I have Honda Moly paste and this stuff http://www.valvoline.com/products/br...ower/grease/63.
I'm not too cheap to get the Permatex Caliper Lube but just wanted to save a trip to the store and $12 if what I have is okay.

[1948man]

Went for the Permatex. By the way, they have it in little plastic paks at the register for $1.29.