been Dazed and Confused

[Guest]

I'd put a hard stop on the proceedings and change the brake lines. I'm doubtful that's the problem but they should be changed regardless. Make sure the banjo bolts are clean and get fresh crush washers at the same time. If you have an Earl's store nearby you can make the lines yourself and save some money (and get them fast.)

Repeating myself but if you are getting strong fluid flow out of the lines at both calipers when the lever is pumped that means the calipers are the problem. More specifically, the pistons are not moving close enough to the disc and/or you have binding in the sliding pins. When in use the caliper piston moves extremely close to disc. When you grab the lever the pressure build up causes the piston to push the pads through incremental movement as the caliper piston seals flex. If the piston doesn't move close enough, or if the sliding pins are sticking, the piston can't move close enough for that hard pad contact to occur and the lever will feel soft. Aftermarket caliper parts can cause this binding to happen; I've fought this same problem several times in my past when K&L brake caliper seals were used. And make sure the sliding pins are lubed with some heavy black moly caliper grease. Not just some general purpose grease. You need the high temp stuff because the calipers can get really hot at times.

Replaced the brake lines yesterday and the brakes are now working. Thank you all.

 

[Guest]

I'd put a hard stop on the proceedings and change the brake lines. I'm doubtful that's the problem but they should be changed regardless. Make sure the banjo bolts are clean and get fresh crush washers at the same time. If you have an Earl's store nearby you can make the lines yourself and save some money (and get them fast.)

Repeating myself but if you are getting strong fluid flow out of the lines at both calipers when the lever is pumped that means the calipers are the problem. More specifically, the pistons are not moving close enough to the disc and/or you have binding in the sliding pins. When in use the caliper piston moves extremely close to disc. When you grab the lever the pressure build up causes the piston to push the pads through incremental movement as the caliper piston seals flex. If the piston doesn't move close enough, or if the sliding pins are sticking, the piston can't move close enough for that hard pad contact to occur and the lever will feel soft. Aftermarket caliper parts can cause this binding to happen; I've fought this same problem several times in my past when K&L brake caliper seals were used. And make sure the sliding pins are lubed with some heavy black moly caliper grease. Not just some general purpose grease. You need the high temp stuff because the calipers can get really hot at times.

Is the sliding pins the round bars the brake pads hangs from? I did not realize those should be lubricated (mine were just dusty and rusty). I polished them shiny though.

 

[Nessism]

Is the sliding pins the round bars the brake pads hangs from? I did not realize those should be lubricated (mine were just dusty and rusty). I polished them shiny though.

No, those are not the pins. I'm talking about the large bolts that the caliper slides on. Suzuki calls them axles. Items 9 & 10 in this diagram...https://www.partzilla.com/catalog/suzuki/motorcycle/1980/gs1000g/front-calipers

 

[Guest]

No, those are not the pins. I'm talking about the large bolts that the caliper slides on. Suzuki calls them axles. Items 9 & 10 in this diagram...https://www.partzilla.com/catalog/suzuki/motorcycle/1980/gs1000g/front-calipers

Ah, the rear caliper is different, that makes sense.

 

[850 Combat]

My suzuki specifies DOT4 on the master cylinder, a square one, not round.

 

[850 Combat]

There is an excellent thread on this site for fabricating your own lines, using super high quality material. Z1 enterprises sells prefab line in a large variety of lengths, and you have to identify and buy your swivel fittings separately. Looking closely at both, I thing the Earls ls less expensive. I didn't find the Earl's website the easiest to negotiate. Z1 may or may not have all the bends of banjo fittings you need.