Bad ABS hydraulic unit/module 2007A, per Yamaha dealer

[Geezer]

Be careful with sharing "Internet Wisdom" with the dealer (no matter how good that advice might or might not be); especially if you ever plan to use them for future work!
They won't appreciate it and they will regard you as an idiot - no matter how well informed you are.

Ross is absolutely correct. However, do you really want to ever trust this dealer who is asking you to spend an enormous amount of money on their guessing without actually diagnosing the problem?

 

[HelzBelz]

Have they thought about changing the lines? Cheaper than an abs module, and would likely solve the trapped air bubble.

Heck, this would be one of the prime reasons to replace lines that otherwise look fine.

(BTW, maybe a local more experienced non Yamaha mechanic might be a better place for bike to be sitting. I would research guys in the area, pick their brains, see if they want a crack at it. )

 

[dcarver]

I can Brodie machining up 'plugs' to block abs module output lines (to the brakes) to prove/disprove the abs block..

 

[rcpd807]

I can Brodie machining up 'plugs' to block abs module output lines (to the brakes) to prove/disprove the abs block..

Can you elaborate further on this? Would this block output lines for testing purposes or be a permanent block to bypass the ABS module?

 

[JamesK]

As others have stated, it is highly unlikely to be an ABS block problem.

It is most likely an air bubble somewhere.

When I replaced the seals in my brake calipers it was a real PITA to get the brakes to be as firm as they should be. Repeated bleeding (with a Mytivac), some brake line tapping and a couple of days of having the front brake lever strapped to the handle bar eventually got all the air out of the system.

I would also suggest you fabricate the jumper described in Ionbeam's ABS testing post so that you can cycle the ABS unit while the bike is stationary. I do this periodically as well as prior to the annual brake fluid flush.

 

[dcarver]

I can Brodie machining up 'plugs' to block abs module output lines (to the brakes) to prove/disprove the abs block..

Can you elaborate further on this? Would this block output lines for testing purposes or be a permanent block to bypass the ABS module?

That was my thinking. Block all ABS module outputs.. but this is way overkill to a simple problem.

 

[rcpd807]

UPDATE!!!!

Got my bike back today from the dealership after they took $617 from me for a bike in worse shape than when I dropped it off. (Ding in tank and tank scuffed).

Anyways, I got it home and performed the ABS check per instructions on this forum and the service manual using alligator clips. The dealership and Yamaha rep that was brought in said I needed a new ABS module.

My findings are this.....I feel 3-4 distinct pulses in the front and rear brake pedal/lever. The front lever still has no pressure and touches the handlebar, but when the ABS module is activated the pressure created is so great I physically can't hold it to the handle bar with two hands. The ABS module makes a sorta loud mechanical sound (not sure if this is normal). I have cycled the system about 10 times. The rear pedal pulse is noticeably stronger than the front lever.

If my ABS module was bad, I would not be feeling pressure and pulsing in my front lever.......RIGHT?

Based on what I have described, what should be my next course of action or place to check next?

Thanks in advance guys.

 

[RossKean]

I'm still not convinced that you or the service guys have been successful in getting air bubbles out of the system. That or a bad (or incorrectly installed) master cylinder.

 

[rcpd807]

I'm still not convinced that you or the service guys have been successful in getting air bubbles out of the system. That or a bad (or incorrectly installed) master cylinder.

I have the front brake lever zip tied to the handle bar currently. I tapped the brake line also as early suggested. Tomorrow I might take the new master cylinder off and reinstall it.

 

[Donal]

I'm still not convinced that you or the service guys have been successful in getting air bubbles out of the system. That or a bad (or incorrectly installed) master cylinder.

I have the front brake lever zip tied to the handle bar currently. I tapped the brake line also as early suggested. Tomorrow I might take the new master cylinder off and reinstall it.

This takes you right back to where you started!

It can be really tricky to get rid of all the air in a brake system after you have opened up any fittings.

I assume you can't see any trace of brake fluid (leaking) when carrying out the ABS checks?

If the front brake system is not holding pressure, tying the the brake lever will not achieve anything. This technique relies on the pressure in the system compressing the air bubbles so they can migrate upwards more easily.

Your best bet is to get hold of a Mity Vac (or something similar) to try and use velocity to move the bubble.

It is possible that your original master cylinder failed and then air was introduced during installation of the new one. So same symptoms but different problem.............

 

[rcpd807]

Your best bet is to get hold of a Mity Vac (or something similar) to try and use velocity to move the bubble.

Mity Vac purchased today. Fingers crossed it is still something simple. Still intrigued from the ABS testing from last night based on the dealership saying I needed to replace the ABS module.

 

[redzgrider]

Bad timing on my part, but I've got to note that I've never seen a vacuum bleeder make a brake system better. The optimum answer is to reverse pressure bleed -- which I don't know of a generally available kit. Motive products makes a series of pressure bleeders, and the round universal will seal to the master cylinder -- but the hose could also be adapted to the bleed screw for reverse pressure.

https://www.motiveproducts.com/collections/import-power-bleeder-kits/products/power-bleeders-single-adapter-bleeder-kit-domestic-adapter-bleeder-kits-power-bleeders-single-adapter-bleeder-kit-import-adapter-bleeder-kits-power-bleeders-domestic-bleeder-kits-power-bleeders-import-bleeder-kits

 

[rickysnickers]

On a different note, is the dealer going to repair/replace your tank they screwed up????

 

[jmdaniel]

On a different note, is the dealer going to repair/replace your tank they screwed up????

Exactly my thought.

 

[Fred W]

I'm going to go against the previous wisdom and just say that the ABS hydraulic block is a complex mechanical device, and it could fail in a mode different than the normal one we typically see where it fails to divert the pressure when activated.

If the spool valves got stuck in a different condition it would be possible that it would always divert the fluid pressure and you'd then never get any brakes.

Air bubbles in the lines can be a problem, but you would still get a small amount of braking, and the lever would be soft and easy to pull to the bar. My understanding on this situation is the lever is firm but no braking at the wheel.

 

[rcpd807]

They are going to fix or replace my tank.

I used a Mity Vac today and still have the same issue.

I took a video and put it on youtube. Let me know if the ABS module is supposed to be making the loud noise mine is making.

 

[Gary B]

Mmmm....

Was the new master cylinder a complete unit ready to bolt on and bleed or was it a seal kit?

Years ago I was service manager in a Yam dealer and I let the guys change the hoses and seals on my FJ1200 (which I still own).

The front brake wouldn't pressurise after bleeding (no ABS on mine) whatever we did. I decided to strip the master cylinder and found that they'd assembled the tapered piston seals backward.

Turned them round, bingo!

If you have a complete new cylinder then it wouldn't hurt to strip it and have a look, I found an image of the piston kit for the FJR (which I assume is the right way round!).

Something I would try is to disconnect the first hose from the master cylinder, blank the open end with something, bleed it and see if the lever goes solid.

Your ABS pump does sound different (louder/running longer?) to my Gen III but that may be that you've still got air in there,

Must be frustrating for you, hopefully it will get resolved soon.

Merry Christmas

Gary

 

[rcpd807]

Mmmm....
Was the new master cylinder a complete unit ready to bolt on and bleed or was it a seal kit?

Years ago I was service manager in a Yam dealer and I let the guys change the hoses and seals on my FJ1200 (which I still own).

The front brake wouldn't pressurise after bleeding (no ABS on mine) whatever we did. I decided to strip the master cylinder and found that they'd assembled the tapered piston seals backward.

Turned them round, bingo!

If you have a complete new cylinder then it wouldn't hurt to strip it and have a look, I found an image of the piston kit for the FJR (which I assume is the right way round!).

Something I would try is to disconnect the first hose from the master cylinder, blank the open end with something, bleed it and see if the lever goes solid.

Your ABS pump does sound different (louder/running longer?) to my Gen III but that may be that you've still got air in there,

Must be frustrating for you, hopefully it will get resolved soon.

Merry Christmas

Gary

The new master cylinder was brand new OEM, the entire unit, not just the seals. It was frustrating months ago. Recently I don't have the words to describe it. When I get a chance I am going to uninstall and reinstall the master cylinder. If that does not work, I am going to purchase a used ABS module from a fellow forum member and give that a try.

 

[Gary B]

Elusive problems can be extremely annoying! Just needs loads of patience.

My FJ1200 was running badly, stripped the carbs hundreds of times, gave up, bought the FJR, looked at the FJ again in minute detail, one high resistance plug cap!!!!! Doh!

I assume that the system has Dot 4 fluid in it and no Dot 5?

I would still try to prove that the master cylinder is good by testing it on its own.

A bleeding technique that works for me on front brakes is to move the brake lever gently backwards and forwards, only about an inch (caliper nipples closed). With the reservoir cap off you can see tiny bubbles coming out of the inlet hole, sometimes the bubble trapped in the piston won't shift but you can see the silvery colour of it, more gentle pumping until it clears.

Best of luck.

 

[JamesK]

They are going to fix or replace my tank.
I used a Mity Vac today and still have the same issue.

I took a video and put it on youtube. Let me know if the ABS module is supposed to be making the loud noise mine is making.

I don't remember my ABS unit ever making this kind of loud noise during testing, maybe FredW is right about some other kind of failure in this unit we have not encountered before.