I continue to have a problem with brakes on the 1200 project.

[John Schmidt]

Below are some pics of the front brake installation, it really has me stumped. No matter what I do, I can't get a solid brake....I can pull the handle all the way to the grip with little or no resistance. I bled the new m/c, have bled the lines numerous times and don't get any air coming through. I've removed the calipers and compressed the pistons all the way so are now fully seated in their respective cylinders and are being held there via a C clamp. Thought I'd try that to possibly eliminate the caliper/piston leak possibility. Still nothing. Twice I've tied the handle down overnight about 3/4 of the way, next day....no joy. The m/c is a new Valkyrie item which I found wasn't needed, it works the same as the old one I had rebuilt so now I at least have a spare. So....new m/c, new SS brake lines, rebuilt calipers. A single line from the m/c to a tee mounted on the lower tree, then a single line to each caliper off the tee. There are no visible signs of leakage, and no wetness around any connections. It's exactly the same system I installed on my Valk about 8-10 yrs. ago and has worked perfectly since. I'm ready to pull the entire system and start over, I'm baffled by it. I've used different methods of bleeding, all with the same results and have gone through over a quart of fluid in the process. I have new slow jets coming today so if they're what I'm looking for, I think I'll drop the brake issue for a time and pull the carbs.....like I need ANOTHER challenge!?!? 

The lid is off the m/c....see the last picture.








This is part of the setup I use, it keeps the reservoir full so you don't have to keep jumping up to refill it during the bleeding process. I've also used it with an air driven bleeder canister which sucks the fluid through nicely.

[BonS]

I'm sorry you've hit the wall of frustration, John. I've read everyone's remedy for getting the air out of a master cylinder such as tying the brake lever overnight, but I have my own method that's served me well. With a closed system I gently work the brake lever with small movements while watching the fluid in the reservoir. Small micro bubbles and sometimes short streams of micro bubbles will flow up from the piston in the master cylinder. They sometimes look as if they're never going to stop as I keep squeezing. Occasionally I'll give it a big squeeze (out of frustration) but I really believe it's the small movements moving the micro bubbles along. Eventually the micro bubbles bubbles stop and then I worry about bleeding the rest of the lines at the wheel cylinder(s). Works for me. I hope you solve your problem soon!

By the way, a naked '77 GL1000 recently followed me home and I'm really enjoying my shop time with her. The spedo says only 13,000 miles. I'll likely have about $3k in her to get her totally road worthy - and that includes valve seals that we've both had so much fun with!

[98valk]

Below are some pics of the front brake installation, it really has me stumped. No matter what I do, I can't get a solid brake....I can pull the handle all the way to the grip with little or no resistance

is that with or without the cover on?
little ball check valve missing?

[John Schmidt]

Below are some pics of the front brake installation, it really has me stumped. No matter what I do, I can't get a solid brake....I can pull the handle all the way to the grip with little or no resistance

is that with or without the cover on?
little ball check valve missing?

Re. with or w/o the cover, hasn't made any difference. I get the same result.
Re. the check ball, the m/c is a brand new Honda unit and it acts the same as the rebuilt one I had on it. Guess I wasn't aware of a "check ball", is that under that tiny removable cover that sits above the hole at the bottom?

[da prez]

  John , remove the brake lever screw and put in a small phillips screwdriver or bolt that is smaller so it is a sloppy fit. It is possible that the piston is not fully returning. I have run into this several times and have used this method to do a fast check. Some times we have to modify the piston or the handle.

                                  da prez

[98valk]

Below are some pics of the front brake installation, it really has me stumped. No matter what I do, I can't get a solid brake....I can pull the handle all the way to the grip with little or no resistance

is that with or without the cover on?
little ball check valve missing?

Re. with or w/o the cover, hasn't made any difference. I get the same result.
Re. the check ball, the m/c is a brand new Honda unit and it acts the same as the rebuilt one I had on it. Guess I wasn't aware of a "check ball", is that under that tiny removable cover that sits above the hole at the bottom?

sorry I was thinking about the baffle. no check ball.
http://www.rattlebars.com/goodies/chromeres2.html

maybe it has to be bench bled like an auto/truck master cylinder when new or after a rebuild to get all of the air out.

[bentwrench]

I use block-off plugs to troubleshoot brake/abs problems. I would start by blocking off the m/cyl.outlet.
Use a shorter bolt with one copper washer or even a fresh nut between the two washers on the banjo bolt.
With the m/cyl. held level,hand pumping should cause all of the air to rise up through the vent hole.
 
If a lever now locks up in a short pull your trouble lies down stream.If not the m/cyl is your culprit.

If the m/cyl is ok you could try raising the calipers up above the m/cyl and see if any air comes out that way.

[gordonv]

Do you ever get pressure build up when pulling on the lever?

[John Schmidt]

Do you ever get pressure build up when pulling on the lever?

Very slight pressure/resistance after multiple pulls on it.

[gordonv]

If it doesn't pressurize, then wouldn't it be more inclined to be faulty/not functioning properly, than just a leak in the line somewhere?

Maybe it needs priming first??

I would suspect that it wasn't working right. Maybe the piston seal/cup isn't working. Damaged, folded. I think with your knowledge, I would be inclined to disassemble the m/c, and inspect it.

[John Schmidt]

Gordon, it's a brand new m/c, and it's acting no different than the used one I rebuilt. I thought maybe it might be the m/c so ordered a new one, no change. I'm at a loss, there are no wet areas indicating a leak at any of the connections, no leaks at the calipers. I've tried everything that has worked over the years and a number of suggestions from members both on here and the Naked Gold Wing site. I've set that issue aside for a while so I can work on the carbs.....again. Changing slow jets, R&R the carbs on the 1200 is a bigger PITA than on the Valk.

[pago cruiser]

I've fought this multiple times.  The problem is that we don't have x-ray vision to see exactly where the air bubble is. And it is an air bubble.

I have settled on the vacuum pump sucking air/fluid down the lies and out the caliper bleeder.  Sounds like you're doing that now.

Next I'd suggest to unbolt the calipers, insert a piece of 1" x 1/4"  x maybe 3" long aluminum into each in order to duplicate the rotor thickness.  Now let them hang as straight as possible (but with the bleeder screw up) and do the suction trick again.

If that fails, next un-bolt your junction block and try it held at a different angle.  Suck again.

If that fails, totally unbolt one of the hoses (I'd start with the one 90 degrees perpendicular to the vertical) from your junction, get a cap from your local brake shop, close off the port, and just bleed one side.  Then bleed the other in the same manner.  Once the problem side has been bled, seems the problem does not repeat when you quickly change from the plug to the hose.  It's only the initial bleed has the issue.

I feel your pain.  I've had no luck in tying off the master cylinder handle.  It has sometimes taken me days to figure out a solution.  With recalcitrant duel brake systems, this last part has worked every time. 
 

[gordonv]

If you don't get pressure, and you've bleed the system to the bleeder screw, I feel the only place there can be air is in the caliper pistons itself.

Correct me if I'm wrong, but I don't know where the lines are inside the caliper, where is the bleed screw on that system? Fluid down the line, into the caliper piston, then out the bleeder screw? Or down the line to the bleeder screw, and then into the piston?

Remove the caliper and hose, piston. Fill with fluid, then place the piston back in, connect to the brake line, and bleed.

Just a thought. Would need to inspect and see how it works.

[Paladin528]

HAve you tried compressing both calipers?
I have had luck after bleeding the traditional way with compressing both calipers all the way back.  This forces any fluid and air back to the MC.
I also notice the brake lines are not the same setup as mine.  I have a bleeder at the T where the lines to the 2 calipers split.

[John Schmidt]

HAve you tried compressing both calipers?
I have had luck after bleeding the traditional way with compressing both calipers all the way back.  This forces any fluid and air back to the MC.
I also notice the brake lines are not the same setup as mine.  I have a bleeder at the T where the lines to the 2 calipers split.

Yes, had both calipers off, used an old pad for both and pressed the pistons so they were fully seated then tried to bleed. The tee is aftermarket, I was looking for one with a bleeder but since it sits over the front fender decided against it(possible paint damage). If you haven't changed the braking system on your bike, it probably still has the split brake system. I got rid of that, the rear is isolated and the front brake handle controls both front calipers, same as the Valkyrie.

[Paladin528]

I am not sure you are following me.
GEt the system FULL and bleed it as best you can.
THEN compress the calipers all the way in then pump the brakes back up SLOWLY.  Compressing the calipers will force any air in the lines back up to the MC.  You can also loosen the banjo bolt and bleed it through there when compressing the calipers.
It may take several cycles.  Letting it sit for a while between tries is a good idea as well.

[Dusty]

John 

I had my front system apart on my Yamaha 600 Sport bike. I was bleeding but could not build up any pressure. I finally pumped the front brake lever like crazy for 2 minutes to build up some pressure and zap strapped the brake lever to the handlebar. When I released the lever in the morning I had a stream of air bubbles coming into the master cylinder. I did this three nights in a row and finally got a good brake

Dusty

[mark81]

When you compress the pistons in the calipers are you getting air bubbles in the reservoir or just fluid? When you pump up the brakes are the pistons in the calipers moving and seating against the rotor? Is the master moving enough fluid but not able to build pressure? Can you see or feel the hoses "balooning" under pressure? You may have to physically put your hands on every inch of hose and squeeze the lever a few times to see if there is a spot expanding more than others. I have said in a previous post about the slides sticking. It may also be possible the piston seals are sticking as well they are square seals designed to retract the pistons slightly when pressure is released but if they are stuck the piston will return too much then the next pull of the lever you waste all of the available fluid displacement just getting the piston to move enough to make contact then there is nothing left to build pressure. Are you using dot4 fluid?  I think ive exhausted all my ideas. If you don't get this figured out soon i may just ride to Florida to see this stumper for myself.

[John Schmidt]

Hey Mark81, come on down, it's not snowing or blowing and the temp is in the 70's. 

Re. the brakes, I compressed the pistons in both calipers but it was difficult to see the m/c action at the same time. It did push fluid back up into the m/c.  The pistons move out to make the pads contact the rotor when you pump the handle. But, when I removed the pads the pistons would only come out just so far and wouldn't move any farther. I'm about done with the carb work I was planning so will be coming back to the brake issue later this week. I might tie back the handle each night for the next few days while I'm working on the carbs....see what happens.

Thanks for the tips from everyone, I've never had such a frustrating experience with brakes before. 

[quexpress]

Hi John,

A while ago, I copied this from another forum (Suzuki if I remember well). I never had to use it but thought that it made sense.

One great fail-safe way I have found in bleeding brake is to go get a clear tube with the inner diameter the same as the air bleeder. I believe it is 8mm. First loosen the bleeder. Put the clear tube on the bleeder with a zip tie. Make sure the zip tie is over the "nut" part and snug it up as tight as you can get it with out breaking the tie. This will keep the fluid from leaking from the tube. Now put some fluid in the tube about 2-3" above the bleeder. Put the other end of the tube up and over the bars with open end facing down (NOT TOWARDS GAS TANK OR ANY PAINTED SURFACE IN CASE OF SPILLAGE).

Now that you have the tube on and bleeder loosened with fluid in the tube, pump the brake lever. You will see fluid shoot into the tube, and if there is air you will see the air rise through the fluid. When you release the lever the brake system will suck back in fluid not air. Keep doing this until you get no bubbles when you press in the lever.

If you tighten the zip tie enough there shouldn't be any leaks and you should be able to spin the tube enough to tighten the bleeder until you take the tube off. Now take the end of the tube and try to put it low so that the brake fluid flows to the middle of the tube and away from the bleeder before you take the tube off.

Now just make sure to snug the bleeder back up. Also make sure that your master cylinder is always full when pumping the lever. And do this to both sides.

Good luck! 

Normand

[Michvalk]

No chance that aftermarket T has a check valve in it? Just a thought

[John Schmidt]

No chance that aftermarket T has a check valve in it? Just a thought

No, it's a clear passage in all directions.

Normand, I've never heard of doing it that way but might be worth a try. I've been tying off the handle each of the last few nights and seems to be making a difference so it's apparent there still is air in there somewhere. Going on a ride tomorrow, might just give your posted idea a try, sure can't hurt.