been Dazed and Confused

[salty_monk]

There are other alternatives to rebuilding stock brakes... I guess you're so far into these now you may not want to change direction

If these are original brake lines I would change them regardless of whether they are causing this issue or not - at that age they are an issue!

Those original 78 model year brakes are pretty pathetic to be honest. Later models are much better.

[Rob S.]

If these are original brake lines I would change them regardless of whether they are causing this issue or not - at that age they are an issue!.

As I recall, owner's manual says change original (rubber) lines every two years!

[Shred Astaire]

Wow, you guys here are all awesome! Thank you very much for all the input! It's been 110F degrees in the carport the past few days so I've only been working short periods of time out there. I'm on it.

[Nessism]

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.

[Shred Astaire]

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.

I thought I'd head to the store this morning and get some large latex gloves and put each one of the calipers in a glove and seal them tight to the hoses and pump to see what happens. Thank you for the functionality of the brake system. I've been trying to figure that out as I go here and you've handed it to me in this post. Thanks Ed!

I'll google earls brake lines and see what pops up locally.

[Shred Astaire]

No Earl's store here in Florida.

I took the MC cup and plate off and cleaned a little more. Both holes squirt fluid when I gripped the handle. The left hole shot fluid and hit my forehead LOL. I don't know what happened to the right side I was too busy bobbing and weaving to notice. The right side was evident with the second more gentile pull. I wrapped both calipers with cling wrap after greasing the pads on both calipers. Cling wrap is shvt. It is now in my trash can and now longer welcome in this house.

The under side of the right caliper was wet with fluid. Just a wee bit. Before I wrapped and checked out the well. I'm going to bring the bike in the house and submerge both calipers in the tub and check for air bubbles. Don't laugh. I've seen air bubbles in the tub before.

[Shred Astaire]

The right front caliper is weeping from the top seal.

[Rob S.]

The right front caliper is weeping from the top seal.

All right! Progress.

Now which one of them four hippies in the avatar is you?

[Shred Astaire]

All right! Progress.

Now which one of them four hippies in the avatar is you?

None, I've only wanted to be in a group since I was drummer in a garage band when I was 13. It's from the movie "Almost Famous" If you want to go back to 1973 for a couple of hours it's a great movie.

https://www.youtube.com/watch?v=_qW9wqUI4Lg

[Rob S.]

You're kidding! I thought it was Led Zep. The eyes are the first to go. And the legs. And...

[Shred Astaire]

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.

[Noreg]

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/su...front-calipers

[Noreg]

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/su...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.