Bleeding split front brake. Is there a trick?

[duggram]

Any advice on bleeding the front brakes? I mounted a high gender which requires splitting the brake lines. I've been bleeding brakes for decades but never on a front brake system where I divided a single inline system into a bifurcated system that went into two, and came through an ABS unit. The procedure described in the service manual sounds like standard brake bleeding. Maybe there's something special about this I don't realize. I get fluid flowing out of both calipers, but I'm not getting any resistance at the lever. Am I overlooking something?

[Canzvt]

28 minutes ago, Bmp4510 said:

The kit simplified brake bleeding on the HD and has worked on many different vehicles, and your able to test for vacuum leaks as well. That what I use for all bleeding chores. Anyone try one on the T7?

https://www.amazon.com/dp/B00265M9SS/ref=cm_sw_em_r_mt_dp_3FMRXBJGXABJ10Z0K7XN
 

I used to own a hydraulic trailer brake actuator/caliper manufacturing company, and we used a MityVac all the time. These were long tortuous path brake lines on all sorts of trailer types. Still didn't work on my GTS as I couldn't get enough flow through the system without the master running dry. The Speed Bleeders were the only thing I could get to work on that bike. The T7 will be MUCH easier.

[kainic]

Directly from Speedbleeder:

 

Front……SB8125L, M8 x 1.25 steel bleeder or SB8125L-SS, M8 x 1.25 stainless steel bleeder

Rear……. SB8125L, M8 x 1.25 steel bleeder or SB8125L-SS, M8 x 1.25 stainless steel bleeder

 

[Kingsize]

Maybe it's been answered before, but if so I've not seen it. 

 

While building up and working on cars/trucks, I've normally done an ABS bleed procedure where I plug in my computer, and depending on the model, start the software and select "start abs bleed procedure". Then the abs goes through a series of valve pulses to bleed all the air out of the system that wasn't completely bled during the regular bleed process. It's standard affair with automotive ABS. Just not sure if it's something that's offered on the Yamaha platforms through access of the data port?

[johnnygolucky]

Super bump. 1 year later. 

OK, so I sold my last T7 and bought a FE501. LOVE that Husky. She's a jackrabbit. 

But I have some longer trips planned and really cant think of a better bike than the Tenere. I missed it. So picked up one barely used and plan to keep both. Best of both worlds. 

So I bought the Camel high fender kit (this is my second time doing this) and installed. Easy enough. 

 

I've now gone through 2 12oz bottles of DOT4 and not seeing any more bubbles, but there is zero resistance in the calipers. Brake handle goes to the bar. 

 

Here's where it initially goes off the rails. I thought I'd try the Speed Bleeders as sold by AltRider for the T7. Installed and couldn't get them to work. They sunk so far into the mount for the brake bleeders it was hard to get a wrench on them. And didnt seem to seal very well, even with the sealing compound on the threads. So figured I'd just go back to the originals that came on the bike. 

 

2 bottles later and I cant get those pistons to bike the disk, even though I'm pumping, crack, close, pump. Lots of bubbles for a while, but no more. Just clear fluid. 

 

I'm losing my mind as I'm not sure what to do. I'm clamping the lever to the bar over night to try that as it was suggested on here earlier. Not really sure what that will do though. 

 

 

UG!

Edited March 18, 2023 by johnnygolucky

[Hollybrook]

Try a rubber band, cable tie or Velcro strip to hold the front brake lever close to the grip and leave it overnight.

 

EDIT: I missed the last line of your post.  I have had success doing that because it lets bubbles slowly work their way up into the reservoir.  If the lever is in the rest position, the bubbles are trapped in the line and when you squeeze the lever, they are pushed back down the brake line.  If they would get all the way to the bleed screw, that would be fine, but they often don't get there because they float back up the line while you are working the lever.  Gravity's a bitch!

Edited March 17, 2023 by Hollybrook

[williestreet]

On 3/16/2023 at 10:49 PM, johnnygolucky said:

Super bump. 1 year later. 

OK, so I sold my last T7 and bought a FE501. LOVE that Husky. She's a jackrabbit. 

But I have some longer trips planned and really cant think of a better bike than the Tenere. I missed it. So picked up one barely used and plan to keep both. Best of both worlds. 

So I bought the Camel high fender kit (this is my second time doing this) and installed. Easy enough. 

 

I've now gone through 2 12oz bottles of DOT4 and not seeing any more bubbles, but there is zero resistance in the calipers. Brake handle goes to the bar. 

 

Here's where it initially goes off the rails. I thought I'd try the Speed Bleeders as sold by AltRider for the T7. Installed and couldn't get them to work. They sunk so far into the mount for the brake bleeders it was hard to get a wrench on them. And didnt seem to seal very well, even with the sealing compound on the threads. So figured I'd just go back to the originals that came on the bike. 

 

2 bottles later and I cant get those pistons to bike the disk, even though I'm pumping, crack, close, pump. Lots of bubbles for a while, but no more. Just clear fluid. 

 

I'm losing my mind as I'm not sure what to do. I'm clamping the lever to the bar over night to try that as it was suggested on here earlier. Not really sure what that will do though. 

 

 

UG!

Sometimes you will get air trapped at banjo bolt fittings and other connection points.  The Camel kit has that large aluminum block with banjo fittings and it is possible there is air trapped in a little nook or cranny in there.

My suggestion would be to squeeze the lever 3-4 times and hold it in with a band or strap.  Then take a wrench and crack a banjo fitting slightly loose. Any air trapped in the banjo fitting should be released.  Make sure you have some rags to catch the leakage.  Do one fitting at a time, and re-squeeze the lever before doing the next fitting.  I would do each banjo fitting from those on the calipers all the way back to the connection on the Camel block maybe even as far as the ABS unit. 

 

If doesn't fix your issue I would remove the calipers, put something between the brake pads approximately the thickness of the rotor like a steel shim, an old brake pad or even an old screwdriver.  Tape it in place so it can't fall out, and raise the caliper as high as possible, preferably handlebar height so the air will easily move up to the bleeders.

Bleed them again and tap along the lines to try and move any air up to the caliper bleeders.  Let them hang over night if you need to.  

 

On other bikes when installing new lines I have often needed to crack loose the banjo bolts at the master with the lever pulled to force out small amounts of trapped air.  I doubt you would need to go back as far as the master, but depending how much fluid came out and how you did your install you might need to go back as far as the ABS module connection.

 

Good luck.

 

 

Edited March 19, 2023 by williestreet

[johnnygolucky]

Thanks all for the help. Not sure if it was one or the other, but I took the bike off the lift and put it on it kickstand, and raised both calipers above the reservoir and left it for the night. After a couple more bleeds, the brakes appear to work great. 

Thanks again everyone. 

[DanDoesStunts]

If I ever have issues doing a regular bleed, I do a reverse bleed and push fluid up the line with a syringe.

 

Works everytime.

[roygilbo]

On 8/19/2020 at 5:53 AM, Canzvt said:

Hmm. While I haven't dove into the T7 front brakes, I do have a LOT of experience with a '93 Yamaha GTS - Yamaha's first crack at ABS. The front brake line is 8.2' long from the bars to the ABS actuator under the seat and then to the caliper on the front swingarm. When I replaces the lines with braided SS ones, the whole system was empty. I used the brake lever to pump fluid into the system to fill it, but bleeding all the air out was a completely different experience. I've done the bleeding 4 different ways.

 

1st was to bleed it like any other Japanese bike - fill the reservoir and pump the lever 2-3 times with the bleed valve closed, then hold the lever and crack the bleed screw. Kinda worked until the ABS actuator got air in it, then not so much. This method only works when there is no significant 'high spots' in the hose between the caliper and the master cylinder, so the air bubbles either go to the caliper or up to the master cylinder.

 

The second way is to use a vacuum bleeder on the bleed screw and make sure the reservoir is always full. Had much better luck with that. Unbolt the caliper(s) and raise them as high as they will go, draw a vacuum on the bleed screw, and draw fluid from the master cylinder. This vacuum should draw all the air out of the ABS actuator if any gets into it.

 

The third way is similar to the second except you use master cylinder pressure and elevated caliper(s) to push the air up by pumping fluid up to the caliper. This is explained in the above posts.

 

My final method was to purchase these little gems - 

Speed Bleeder Main Page

that consist of a check valve in the bleed screw. Don't need to remove my caliper, or use the vacuum bleeder, or anything else. Just use the brake lever to build pressure, with the bleed screw cracked, and let the check valve do its magic. Took my by-annual brake dis-assembly/re-assembly and bleeding on the GTS from about 2 hours to about 30 minutes.

 

Finally, the front and rear brakes are separate fluid circuits. Removing the front lines/hoses/calipers will not affect the rear bakes.

 

Good luck.

The above pic does not open.  Can you repost it?

[Canzvt]

1 hour ago, roygilbo said:

The above pic does not open.  Can you repost it?

Speed Bleeder Main Page

 

[roygilbo]

On 4/14/2023 at 12:16 PM, Canzvt said:

Speed Bleeder Main Page

 

Thanks.  Which ones to order for the T7?  Also, did you order the thread sealant? 

[Canzvt]

6 minutes ago, roygilbo said:

Thanks.  Which ones to order for the T7?  Also, did you order the thread sealant? 

I don't have them on my T7 as I find the brakes very easy to bleed on this bike. But, I believe Yamaha usually uses the 8x 1.25mm ones. You will have to check into that before ordering.

[roygilbo]

2 minutes ago, Canzvt said:

I don't have them on my T7 as I find the brakes very easy to bleed on this bike. But, I believe Yamaha usually uses the 8x 1.25mm ones. You will have to check into that before ordering.

Gotcha.  Thanks. 

[Canzvt]

12 minutes ago, roygilbo said:

Thanks.  Which ones to order for the T7?  Also, did you order the thread sealant? 

Oh ya, Sorry. Forgot. Yes, order them with the sealant. It keeps things a LOT cleaner when you crack them to bleed. The fluid only comes out of the hole, instead of around the threads.