Rear brake failure.

[limey]

Went for my first long ride of the year yesterday (600km) and noticed I had no rear brakes . Put her on the centre stand and run the bike in first gear hit the front lever and nothing hit the rear and nothing wheel still kept spinning . Anyone else had this problem? I will take it in tomorrow as it is still under warranty.

 

[~TABASCO~]

Went for my first long ride of the year yesterday (600km) and noticed I had no rear brakes . Put her on the centre stand and run the bike in first gear hit the front lever and nothing hit the rear and nothing wheel still kept spinning . Anyone else had this problem? I will take it in tomorrow as it is still under warranty.

I know that im about to change out three sets of customer rear pads... Mi range from 12-15K Fronts look good,, back are toast...

 

[limey]

Thanks but the rear pads are good. Failed to mention the rear brake lever bottoms out as well .

 

[markjenn]

We had a discussion a while back about whether you could test the linked nature of the rear braking by running the bike on the centerstand and concluded you probably couldn't. But if the rear brake pedal is bottoming without any action at the caliper, you obviously have a failure of some sort. Let us know what the dealer says.

- Mark

 

[num]

If the pedal bottoms out, try to pump it and see if you get pressure, If not check the fluid level, If the fluid is fine, bleed it and then top it off.

 

[Obrianmcc]

My vote is that you have a seal failure either in the master or the caliper.... take it in and get it fixed.

 

[greg the pole]

Second the option on the rear pads.
Mine were toast at 25 KM. New set of EBC's went in.

Fronts are a-ok.

 

[limey]

If the pedal bottoms out, try to pump it and see if you get pressure, If not check the fluid level, If the fluid is fine, bleed it and then top it off.

Looks like you win num, the dealer bled the rear and it feels fine now. Thanks every one for your input.
Paul..

 

[offcamber]

I think I remember trying the linked brakes on the centerstand and the rear wheel does stop with the front lever engaged. I'll have to try it again.

 

[limey]

Update, the bike has been out of commission for about three weeks because of the fork rebuild by Nick at Stoltec Motor Support. Anyway this gave me the chance to bleed the brakes again. I went by the manual right front, left front then the rear. This is the third time I have bled the brakes and the dealer twice. The rear feels fine when you are sitting stationery and once I ride a few feet and apply the rear the lever travels all the way and that's it, no rear brakes . So I bleed them again lots of air from the rear brakes, feels fine when statonery and the same thing happens when I take off. I think it's the ABS unit under the seat. So it's off to the dealer tomorrow. I'm off to Americade on Saturday guess I have to take the Roadglide that was about to be sold. Need this sorted out as I was thinking of leaving for Colarado on the 17th.

 

[GrahamD]

I think it's the ABS unit under the seat. So it's off to the dealer tomorrow.

Damn, That's the only German part on the bike.

 

[limey]

Why would it be sucking in air and there is no oil leaking.

 

[GrahamD]

Why would it be sucking in air and there is no oil leaking.

::017:: Don't know. There is lots of stuff in there. It's probably a 10 cent piece of rubber.

 

[creggur]

Rear brake failure.

Seen this in cars - ABS unit starts aerating fluid for no apparent reason, and no amount of bleeding will resolve it. Replacing the ABS unit has fixed it every time.

 

[oprider]

I encounter same issue here with numerous bleeding done...
Is that really abs unit failure?
How much will the abs unit cost and which part of web site can i get as i dont want to get it thru local agent.

 

[Uncle Dave]

I encounter same issue here with numerous bleeding done...
Is that really abs unit failure?
How much will the abs unit cost and which part of web site can i get as i dont want to get it thru local agent.

Mine did the same about 18 months ago. After a long fault finding session it turned out to be a fault with the ABS unit. It was bleeding internally and always lost pedal pressure after riding for a few metres.

Over $1000 later and all is fixed. Was only a few months out of warranty but Yamaha Australia helped out with supplying the part at near cost price.

 

[Brick]

limey what was the final determination on your bike? Was it the ABS unit?

 

[Old Git Ray]

I am now suffering the same problem (48k miles). I keep bleeding the rear and after a while it gets more and more spongy and eventually gives up. There is (obviously !) air in the system each time, so I rang Yamaha technical UK if it could be the ABS unit and they said emphatically NO. Even if it fails, it would not let air in. He suggested the master cylinder seals so I am going to order a complete set of seals, front and back, master and slave, and replace the lot.

 

[AVGeek]

Correct me if I'm wrong, but with the linked brakes, does pushing the rear pedal activate any of the pots in the front calipers? I know the FJR has this setup, and when mine was spongy on the rear brake, I had to bleed the line to the front caliper.

 

[Uncle Dave]

I am now suffering the same problem (48k miles). I keep bleeding the rear and after a while it gets more and more spongy and eventually gives up. There is (obviously !) air in the system each time, so I rang Yamaha technical UK if it could be the ABS unit and they said emphatically NO. Even if it fails, it would not let air in. He suggested the master cylinder seals so I am going to order a complete set of seals, front and back, master and slave, and replace the lot.

I replaced the rear master cylinder first but made no difference.

***It was most definitely the ABS unit***