Soft/Mushy Rear Brake Pedal

[Valkmike]

Just checking to see if anyone has had to deal with a soft or mushy rear brake pedal. There seems to be a lot of travel in the pedal and takes longer to engage the rear brake.

Had the bike in for service and the owner mentioned it to me when he took it for a final test ride. He changed the brake fluid (front and back) and bled the rear but it feels the same.

Not overly concerned with it but interested to see if anyone else has experienced this.

2013 with about 10,000 miles.

Thanks for any feedback out there.

 

[RossKean]

Bleed the lower front piston pair using the rear brake pedal (linked brake). Then bleed the rear brake. Run lots of fluid through! Your problem is almost certainly a bubble that didn't get pushed through. Common issue, especially when the linked front is not done first.

 

[Geezer]

Not my '05, but my buddy Thingfish has a newer FJR and had a similar problem. It took several iterations of very thorough bleeding to solve the problem. The linked brakes require a particular sequence of bleeding, so that adds to the complexity.

 

[Harald]

Your mechanic may not realize that the brakes are linked as RossKean posted. That would definitely explain your problem.

If the rear is still mushy after a thorough bleeding, you can also try another trick. Hang a heavy weight from the rear brake pedal and leave it there overnight. The constant pressurization of the fluid can move the air up to the high point (the reservoir) where it can get out.

 

[mophead]

My 08 had to be bled once a year due to soft rear pedal. Happens on these bikes and a buddy's Goldwing. Just bleed as explained above and it will return to normal.

 

[Steel_Gin]

My pedal went down further than before after a brake fluid flush. Did the already suggested weight hung off pedal, but did it for 24 hours since I worked the next day. When I got back to it on the 5th pump I saw a small bubble come out. Just to make sure I did 20 pumps on the front and 20 on the back, all is well now. Hope you can get it fixed.

 

[rbentnail]

Maybe try manually cycling the ABS a few times. That helped mine one time.

 

[Valkmike]

Thanks for the input ...... I'll try both solutions suggested.

 

[wfooshee]

Is this always or only after a few miles? In other words, is the pedal firm when you first get on the bike? If so, it may be that the pedal is not releasing fully and you're getting just enough rear drag to boil the fluid and fade the rear.

The pedal pivot gets gummed up over time and needs to be cleaned every year or so.

But if the rear is soft when it's stone cold, then you're back to thorough bleeding, as stated previously.

 

[BanjoBoy]

Maybe try manually cycling the ABS a few times. That helped mine one time.

^THIS^

'N VTHISV

https://www.harborfreight.com/brake-fluid-bleeder-92924.html

 

[900gc]

Also, try keeping the pedal depressed firmly (I wedged a plastic tube between it and the handlebar) for a couple of days straight (and hand lever squeezed since it is linked). A trick I learned from the DRRiders forum to firm up the brake feel. Apparently it forces any trapped air bubbles to the reservoir. Works the nuts on my '08, nice firm pedal all the time now.

 

[RossKean]

Also, try keeping the pedal depressed firmly (I wedged a plastic tube between it and the handlebar) for a couple of days straight (and hand lever squeezed since it is linked). A trick I learned from the DRRiders forum to firm up the brake feel. Apparently it forces any trapped air bubbles to the reservoir. Works the nuts on my '08, nice firm pedal all the time now.

Hand lever does not affect either the back brake or the lower right piston pair. That pair is ONLY a part of the rear brake system.

 

[K_Flyer]

When I first got the FJR, I complained about the rear brake being very ineffective and needing a long throw. Dealer's response was a) they're all like that, and B) you shouldn't be using the rear brake. So I put up with the long throw, until last week. I took Theresa's bike to the shop for service and found that her rear brake was just as it should be; short throw and quite effective. My bike had just been serviced (new shop) and the tech pointed out that the rear brake was spongy. It was worse after I had a problem recently when a small rock wedged under the rear brake lever and overheated the rotor. When we went in to pick up Theresa's bike they were able to fit in servicing the rear brake (drain, fill, bleed, cycle the ABS...) and now It works the way it should. The bike had been in to the previous shop 5 or 6 times and no one noticed the problem.

Surprised to hear that some bikes develop a spongy rear brake over time, but good to hear of a fix.

 

[Mad German]

You mean these bikes have rear brakes...? I just grab the front brake lever and call it a day.

 

[RBEmerson]

What about using the HF vacuum pump? Also, are speed bleeders a possibility?

 

[rbentnail]

What about using the HF vacuum pump? Also, are speed bleeders a possibility?

Yes. Yes.

Whatever makes you happy.

 

[RossKean]

What about using the HF vacuum pump? Also, are speed bleeders a possibility?

Both are possible and neither is necessary. I figure that Speedbleeders might save me 10 minutes on a one hour job (bleeding front and rear brakes and clutch) every two years - never thought there was any point. Vacuum bleeding only (possibly) needed if you are filling a "dry" system. Bleeders and vacuum pump are needed more if you are trying to do an automotive system by yourself where you can't get to the bleeder nipple while activating the brake pedal.

 

[RBEmerson]

Ask and learn.

 

[RossKean]

Ask and learn.

Lots of people swear by the Speedbleeders - I just never felt them necessary (for me).