Rear Brake Failure (NOT disc or pads)

[Mzee]

My rear brake is not working properly. I had to pump it, for it to work. We all know that is not good for emergency braking. So I took in to Yamaha in my neighborhood. They said it had to do with . .Cylinder Kit, Master (23P-W0042-50-00). I bought the new parts. Had it installed. But the brake is still not working. I have taken it in for a third time. First they bled the rear brake system. The second time the did the same but this time including the abs. The rear brake is still not working completely. They have decided to contact Yamaha national for a solution. Any one come across this problem before. Can anyone help. What kind of problem might this be?


Thank you.

 

[pnelson]

Re: Rear Brake Problems

Mine just started doing the same thing. It's a 2013 with abut 12,000 miles.

 

[Uncle Dave]

Re: Rear Brake Problems

Guys, I had exactly the same issue and it was the ABS unit that was faulty. Cost me over a grand as it was out of warranty, there was some discussion about a year ago as a couple of others had the same issue.

 

[Dogdaze]

Re: Rear Brake Problems

Bad ABS motor, this may be of use to someone... based in the US on fleabay.

http://www.ebay.co.uk/itm/13-Yamaha-XT-1200-XT1200-Z-Super-Tenere-antilock-brakes-ABS-pump-anti-lock-/311374694731?hash=item487f60c94b

 

[Tyke]

Re: Rear Brake Problems

As this is a brake related issue its also clearly safety related

I hope Yamaha are aware and acting accordingly :exclaim:

 

[Mzee]

Re: Rear Brake Problems

But shouldn't the ABS light come on then to indicate there is a problem? Mine does not come on. In addition if the entire hydraulic system needs changing, because that is what the unit above seem to indicate, wouldn't it also imply that the front system is itself faulty which in my case is not true. The hydraulic system controls both front and rear brakes, if I understand correctly. I have attached what seems to be the offending unit.

 

[Mzee]

Re: Rear Brake Failure

I had no way of knowing, but I refused to believe that some thing was amiss with the ABS cylinder since the front brakes were still functioning, and as far as I know they use the same cylinder as the rear brakes system.

After four attempts to fix it failed at my local yamaha dealer, the bike was sent to HQ. A week after it was returned, the problem resurfaced. After two months of riding and not actively using the rear brake, it turns out that the rear brake started working again as good as new. What is the explanation? Please don't say it was the ABS cylinder failure?

I also had my rear master cylinder replaced but initially with no difference.

 

[superjet]

Re: Rear Brake Failure

I hate to tell you, but it probably is the ABS pump. I am going through the same thing right now. (2012 Super Tenere with 30,000 in it)
http://www.yamahasupertenere.com/index.php?topic=7940.0

(I am embarrassed to say I haven't really ridden since October)

I just put my bike on the lift this morning and I am trying to figure out the best way to bypass the ABS pump

 

[bigbob]

Re: Rear Brake Failure

Search for pump by eemsreno. He said how he bypassed his last May.

 

[superjet]

Re: Rear Brake Failure

Thanks Big Bob. I saw that and tried following it, but I can't find a cap nut to fit the banjo bolt anywhere. I am going to attempt to weld a plug on the end of a nut to make my own cap. It's always something

 

[sigeye]

Re: Rear Brake Failure

I just discovered that my rear brake fluid reservoir is totally empty. I check it every couple weeks because I ride very often and I didn't notice anything until my brakes felt spongy a couple days ago. Came home and found the reservoir empty. No idea where the fluid went because there are no traces of leaks anywhere nor on my garage floor. Thoughts?

Sent from my SM-G920V using Tapatalk

 

[Juan]

Re: Rear Brake Failure

I just discovered that my rear brake fluid reservoir is totally empty. I check it every couple weeks because I ride very often and I didn't notice anything until my brakes felt spongy a couple days ago. Came home and found the reservoir empty. No idea where the fluid went because there are no traces of leaks anywhere nor on my garage floor. Thoughts?

Sent from my SM-G920V using Tapatalk

Do you mean absolutely empty or at the minimum level? If it's completely empty, then you must have a leak somewhere (assuming it was full at some time). It the level is at the minimum, you must be at the very limit of the rear brake pads. If this is the case be careful because you will ruin the rotor if the pads are completely worn out.

 

[Mzee]

Re: Rear Brake Failure

I don't know how but my brake fixed itself and works perfectly. I honestly have no explanation how after it failed closed to three months. I kinda suspect there was an air pocket in the system that eventually cleared itself. The mechanic at my local Yamaha was unable to give a plausible explanation.

 

[silvergoose]

Re: Rear Brake Failure

It sounds like an air bubble in the brake fluid line leading from the ABS pump. You say the reservoir is empty, I must assume you have been riding for a while with the fluid low/out. If during that time the ABS pump was activated air could/would be ingest into the pump. The air in the pump line would act as a block and not allow fluid into the reservoir. If the bike has been sitting for a time the air bubble will rise to the top( ABS pump). Check all of the brake system, it was noted that excessive pad wear along with low fluid levels can lead to air ingestion.

Good Luck

 

[OldRider]

Re: Rear Brake Failure

Looks to me like all you need to do is run a line from the rear master cylinder straight to the rear caliper and a line from the front master cylinder down to the left front caliper and get rid of all the abs lines and pump. There are plenty of sources to buy lines what ever length you want.

 

[2daMax]

I encountered this issue on my friend's S10. He came to me after a couple of failed attempts fixes by the mechanic.

The rear brake pedal when depressed was like as if there was a leak at the zerk fitting. Not even spongy. I proceeded to bleed the fluid n after 3 rounds n no improvement, decided to actuate the abs pump.

I jumper the connector that is under the seat. It is a 4 pin connector. Short the blue n black wire. I used a fat wire with both ends stripped. Set the kill switch to off. Turn the key ON. If the jumper is shorted correctly the ABS lamp on the instrumentation will flash. Press n hold the start button for 4 secs. Then simultaneously press n hold the lever n pedal. The abs pump will go through a sequence of pumping n stops after about 10 secs.

Bleed the rear n air bubbles would be seen coming out. The rear brake would feel normal again. If the symptoms return..repeat the procedure to rid the air in the pump.

 

[limey]

My rear brake is not working properly. I had to pump it, for it to work. We all know that is not good for emergency braking. So I took in to Yamaha in my neighborhood. They said it had to do with . .Cylinder Kit, Master (23P-W0042-50-00). I bought the new parts. Had it installed. But the brake is still not working. I have taken it in for a third time. First they bled the rear brake system. The second time the did the same but this time including the abs. The rear brake is still not working completely. They have decided to contact Yamaha national for a solution. Any one come across this problem before. Can anyone help. What kind of problem might this be?


Thank you.

Sounds like your ABS unit is gone, mine was one of the first to go and I was lucky it was still under warranty but I did loose 3 days riding at the Ouray rally. And I believe it's the only German part on the bike.

 

[2daMax]

Researching why there are air in the pump.....http://www.taurusclub.com/forum/82-maintenance-repair/228618-how-does-air-get-trapped-abs-unit.html

No leaks. Just trapped air that needs to be constantly removed until they are gone.

 

[mugrunch]

I have this problem. S10 2012, 40,000 miles. Last service the guy changed all the fluids, since then I've had a problem with the rear brake, had it bled again (twice) no brake unless you pump it. But if I grab the front brake when moving the rear pedal stiffens and if I apply a bit of pressure on the pedal I can release the front and still use the back brake until I release the pedal, then back to normal no brake!

 

[Dogdaze]

Sounds like air in the ABS pump, caused by human error or a leak in the lines, try the suggestion in the previous post by 2daMax, if that fails, worst case scenario is fault with the ABS pump, that has happened and it's not cheap! Could just be a loose hose, check all those first. Good luck.