WARNING Front Brake Seizing

1057 Views 58 Replies 9 Participants Last post by Mitchell, 4 d ago

Mitchell

Discussion Starter · 26 d ago

My latest experience while riding was a bit scary to say the least. I was glad I wasn't on the highway. After about 30 minutes on the Rune it came to a abrupt stop on its own. The front wheel locked up in the middle of the road. Thanks to a few guys they helped to block traffic. After having the bike towed to the shop we foud that the brake fluid was contaminated so we bleed the brakes cleaning the master cylinder and calipers only for it to happen again. I was expecting it to happen so I was taking it easy when it happened the second time. Upon further inspection in the reservoir there is a valve that allows brake fluid to flow both ways one upon applying the brake and the other on release. We noticed on port on the the valve was secreting cloudy brake fluid and realized the flow of brake fluid was restricted. We have ordered the parts and will update this post when new valve is installed.

If I was traveling at 60-70mph on the highway it could have gone very wrong. If you haven't been changing your brake fluid on a constant basis 3-5k mile I would have the valve change and an bleed the system, clean the calipers etc... My bike was scheduled for a fluid change but it wouldn't have helped the brake fluid was in the system too long.

If your bike slows down by itself it is the caliper overheating and putting pressure on the pads as if you were squeezing the brake handle. Pull to the side ASAP. Once it seizes it takes 20-30 minutes for the system to cool before the front wheel will role. I was in the middle of the street waiting for it to cool. Lucky to have a car behind me blocking traffic.

We are pretty sure it is the valve in the reservoir but will follow-up with this post with the results.

Drive Safe

Mitchell

Reactions: 2

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RUNE~GEARHEAD

· #2 · 26 d ago (Edited)

"IMO-Miles isn't the issue between fluid changes, it's that many overlook the time interval of a required fluid change. If the S/M was followed, Runes would have had their brake fluid changed many, many, many times by now. I'd guess that it takes years and years and years for many Runes to get 3-5K miles on them. Heck, I'd guess many Runes have NEVER had the fluid changed even once.

Did you find any evidence of any deterioration of any parts when you disassembled. Like the underside of the diaphragm.

Thanks for the thread! and heads up on possible problem.

Note to SKIP: tire problem solved, on your long ass trips you can stop @ 3-5K miles and do the brake fluid and change tires at the same time!"

Reactions: 1

Dr. Dave

· #3 · 26 d ago

Thanks for this info!!!

Reactions: 1

Skip

· #4 · 26 d ago

RUNE~GEARHEAD said:
Note to SKIP: tire problem solved, on your long ass trips you can stop @ 3-5K miles and do the brake fluid and change tires at the same time!"

Good idea; never thought of that.
What saddlebags do you suggest I get to carry all those spare tires (and brake fluid) on my 10,000 mile trips?

skip

Mitchell

Discussion Starter · #5 · 25 d ago

RUNE~GEARHEAD said:
"IMO-Miles isn't the issue between fluid changes, it's that many overlook the time interval of a required fluid change. If the S/M was followed, Runes would have had their brake fluid changed many, many, many times by now. I'd guess that it takes years and years and years for many Runes to get 3-5K miles on them. Heck, I'd guess many Runes have NEVER had the fluid changed even once.

Did you find any evidence of any deterioration of any parts when you disassembled. Like the underside of the diaphragm.

Thanks for the thread! and heads up on possible problem.

Note to SKIP: tire problem solved, on your long ass trips you can stop @ 3-5K miles and do the brake fluid and change tires at the same time!"

Your right mileage is inconsequential. We have'nt disassembled the reservoir yet but will report back when new valve arrives. Also, went back to OEM Dunlop tires, on order as well.

RUNE~GEARHEAD

· #6 · 25 d ago (Edited)

"Not saying mileage isn't important.

There are those Rune owners that the S/M 12K fluid change interval happens before the 2-year interval time has passed.

(IMO) Until the cause of the situation is determined the best an individual can do is
follow the S/M and do the scheduled maintenance as required, be that by mileage or by time interval(s)."

Mitchell said:
We have'nt disassembled the reservoir yet but will report back when new valve arrives.

Mitchell

Discussion Starter · #7 · 24 d ago

I broke my own rule of changing all fluids when I buy any vehicle. Like I said before I am not sure it would have made a difference in this case. I'll know more when I do the autopsy.

Reactions: 1

MO Rune Rider

· #8 · 23 d ago

I used to change brake/clutch fluid in all my bikes each year religiously. However, with time, age and riding fewer miles, I currently do the changes only every other year. I think the manual actually says every 24 months anyway.

Oddly enough, and lazy on my part, I only do this on all five motorcycles in the garage. I don't do it for my cars, trucks, four wheelers, or tractor.

Mitchell

Discussion Starter · #9 · 23 d ago

Whats interesting is I put nearly 1000 miles on it without an issue. There must have been buildup in the resevoir that broke loose and clogged the back and forth flow of the fluid where it left the brake pads on the rotor, heated up and and seized. As soon as she cools of she's ok, for 15 minutes. But anyway, that's what I think is happening. Will know more when the new valve arrives and I pull the old one out. I'll post the results

MO Rune Rider

· #10 · 23 d ago

Mitchell said:
Whats interesting is I put nearly 1000 miles on it without an issue. There must have been buildup in the resevoir that broke loose and clogged the back and forth flow of the fluid where it left the brake pads on the rotor, heated up and and seized. As soon as she cools of she's ok, for 15 minutes. But anyway, that's what I think is happening. Will know more when the new valve arrives and I pull the old one out. I'll post the results

At this point, it might also be time/money well spent to go through both the front calipers as well. Clean cups and new seals down there as well to ensure nothing hanging up inside either one of them as well. I had that exact same thing happen 100+ years ago & in a different life time on a Yamaha XS1100 I rode at the time. The front locked up and wouldn't move. It was then that I started flushing all the brake fluids on all my bikes annually.

Mitchell

Discussion Starter · #11 · 23 d ago

Good suggestion. We did that on the first go around. Now process of elimination.

Thanks for the input.

AutoRune

· #12 · 18 d ago

I have a Kawasaki Bayou quad from 1989 only has about 20 miles on it so it just sits in my shop but one day it wouldn't roll I removed the master cyl cover and that released enough pressure to allow it to roll I assume it picked up moisture (WA state at the time) I ended up replacing the master cyl but thats probably not as easy with a Rune

Mitchell

Discussion Starter · #13 · 17 d ago

It seems to be the valve inside the reservoir. It allows the back and forth flow of brake fluid. If the flow is only to the caliper and not back to the resevoir after 20 minutes or so it will keep the brake pad pressed up against the rotor, overheat and lockup until it cools. After it cools your good for a another 20 minutes. It seems that the fluid seeps back into the reservoir. Changing the valve will post when I know for sure.

Reactions: 1

RUNE~GEARHEAD

· #14 · 17 d ago

"@13:29+"

Motorcycle Brakes - How Master Cylinders Work and Brake Fluid Explained - YouTube

Mitchell

Discussion Starter · #15 · 17 d ago

Thanx, going to take a look.

Mitchell

Discussion Starter · #16 · 17 d ago

That explains exactly what is happening. The piston in the hand brake is not returning past the port and allowing the fluid to equalize the pressure keeping the pads pressed against the rotor. My mechanics are Brazilian and they don't always use the right terminology but I think we're talking about the same thing. Thanks for the video. I will talk to my guys tomorrow and make sure.

MO Rune Rider

· #17 · 15 d ago

What Autorune said hit a memory switch in my brain. - be sure you don't have too much brake fluid in the reservoir, or when the fluid warms it could swell slightly and won't have room to return as normal and could hold the brakes ON. Yes, I've been there and done that at least once in the past.

Conversely, on a previous Yamaha bike, I even (routinely) kept the fluid too low and couldn't figure out why I kept getting air in the clutch line even though I'd re-bleed and rebleed multiple times and still come back with air in the line. I was simply leaning the bike low enough in the corners to introduce air while operating the clutch day to day.

Mitchell

Discussion Starter · #18 · 15 d ago

Thanks for the reminder. Fluid just changed by a Pro and levels are correct. BTW, The following link is someone I follow and his brake fluid change is interesting. Going to use this technique on My Harley Road King. Delboy's Garage

. Was going to do it on the Rune before seizure of the brakes. Watched a great video that Rune GearHead sent me. Motorcycle Brakes - How Master Cylinders Work and Brake Fluid Explained - YouTube Going to try one of the suggestions with fishing line to clear the Port in the reservoir.

RUNE~GEARHEAD

· #19 · 15 d ago (Edited)

"WTF! Why would anyone use their mouth and a clear tube and suck up/out the old brake fluid to remove it? I've always removed the old brake fluid vs pushing it through the line. I use one of these, works great, and serves other purposes as well, comes with a hose extension for a further/deeper reach."

"Edit:
I disagree with leaving some fluid in the reservoir bottom to prevent getting air into the system. You're bleeding the brakes to replace the old fluid with new, and to remove any air/debris/sediment from the system. Leaving fluid on the bottom is where the sediment/debris rests, IMO- better to remove it than run through the system. Any air
added will be removed if the brakes are bled correctly.
Not many think about the conditions when one does a brake fluid change, good to see him cover that.

Plus: Speedbleeder(s)!"

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Mitchell

Discussion Starter · #20 · 15 d ago

I guess when you don't have a plunger on hand you use what you have. He even says before he did it he was going to hear some Sh..

Reactions: 1

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