Front brake locked up

poopbutt444
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22
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Location
Grand Rapids, MI US
Edited Date/Time 9/8/2017 3:11pm
The other day I landed a 90 foot table and started swapping really hard and crashed. I had hit this fine all day long and cannot figure out what had happened. After I crashed I noticed my front brake was locked up, but as soon as I started going again in broke free and was fine. Is it possible that the front brake locked up upon landing. I know I was a little low on brake fluid and once in awhile it would get a little spongy during the day. I also realized when I got home that my rear tire was flat, but when I pulled the tube it had a very tiny hole in it (would have prob taken days to go flat). Either way I am very confused about it.

Do front brakes locking up in a big crash happen often... or does it make more since that it locked up before the crash.
By the way the rotor is not severely bent but does slightly rub when spinning the wheel.

Any ideas would be appreciated because this crash really has me rattled.

Thanks
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Paw Paw
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Benton, LA US
9/6/2017 9:15am
The rotor should be straight. If warped it will effect the breaking. Not good! It can cause the wheel to stop rotating while in the air off a jump. Fix or replace the rotor.
Crashes do damage the master cylinder from time to time. It may need a rebuild or replacement.
Running with low fluid is just asking for trouble.

Paw Paw
poopbutt444
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Grand Rapids, MI US
9/6/2017 10:52am
I dont think the rotor is bent enough to cause any sort of issue. You can just slightly hear it rubbing on the pads when spinning. Isnt it supposed to rub on the pads a little bit? Also I was having issues before this with the front brake lever becoming stiff after a hard landing. Is that part of this?
imoto34
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9/6/2017 11:52am
Same issues as your last thread in a way? What did you do about the stiffness?

http://www.vitalmx.com/forums/Tech-Help-Race-Shop,42/Front-brake-stiffn…


If the brake locked even once you have a issue. Before you get your self hurt, have someone help you that knows what they are doing, in person and not from a message board. You can never go fast and have fun if your wheel was to lock up and break your neck.


Your rotor is not the problem, if it was it would show while on the stand. Personally, I would start with your line as mentioned in your previous thread by Joe.


DO NOT RIDE AT ALL IF YOU ARE HAVING THESE ISSUES. Remember, we all ride because of a passion for moto. Wadding up and couching yourself will happen eventually but make sure it happens cause you messed up riding, not because a mechanical issue.



Acidreamer
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9/6/2017 12:42pm
I would take it safe and rebuild your caliper and master cylinder and even throw on a new brake line. Thats not an expensive fix and it gives peace of mind. Much cheaper than surgery.

The Shop

poopbutt444
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Location
Grand Rapids, MI US
9/6/2017 6:03pm
So I took the caliper off and everything seemed fine as did the brake line. One thing I was curious about is I have my lever tilted down quite a bit and with the ktm lever it makes the reservoir not level with the ground. Could that cause an issue?

I lubed up the slide pins on the calipers and put it back together and bled the brakes.

Could this be the cause of the crash or is it more likely it happened from the crash? I just don't see how a crash could cause the brake to lock up like that with no visible damage to anything. I'm sure my tire was really low at the time which could of done it too. Just really confused
Paw Paw
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9/6/2017 8:07pm
You know, you came on here asking for help. Help and advise was give and all I hear is excuses as to why those should be ignored.
You have been given good advice , so either use it of forget about it.

Paw Paw
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Colgate, WI US
9/7/2017 6:02am
Is the caliper floating smooth freely? it needs to float maybe the pins are corroded?
Acidreamer
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9/7/2017 6:12am
So I took the caliper off and everything seemed fine as did the brake line. One thing I was curious about is I have my lever...
So I took the caliper off and everything seemed fine as did the brake line. One thing I was curious about is I have my lever tilted down quite a bit and with the ktm lever it makes the reservoir not level with the ground. Could that cause an issue?

I lubed up the slide pins on the calipers and put it back together and bled the brakes.

Could this be the cause of the crash or is it more likely it happened from the crash? I just don't see how a crash could cause the brake to lock up like that with no visible damage to anything. I'm sure my tire was really low at the time which could of done it too. Just really confused
"Visibly" ok does not mean its ok. With tight clearances in the brake system and in the motor, you cant tell if something is .001" off by looking at it. You cant see a .001" thick spec of dirt or metal jammed in a .0009" clearance slot by looking at it.
poopbutt444
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Grand Rapids, MI US
9/7/2017 10:32am
Well I guess I'm going to have someone else take a look at it this weekend. The question I still have is how could a front brake lock up in a crash?? It doesn't seem possible unless the brake lever pushe'd the reservoir piston all the way in and it got stuck. Which was not the case. The lever wasn't even bent nor did it even move.
Acidreamer
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9/7/2017 11:21am
Well I guess I'm going to have someone else take a look at it this weekend. The question I still have is how could a front...
Well I guess I'm going to have someone else take a look at it this weekend. The question I still have is how could a front brake lock up in a crash?? It doesn't seem possible unless the brake lever pushe'd the reservoir piston all the way in and it got stuck. Which was not the case. The lever wasn't even bent nor did it even move.
Crash could have knocked some dirt loose in the system. The caliper pistons are nasty. Rebuild them and youll see.
captmoto
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Rancho Cucamonga, CA US
9/7/2017 10:05pm
This happened on my CR250. I think I mentioned this when you first asked about your problem a while back.

kzizok
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9/7/2017 11:05pm Edited Date/Time 9/7/2017 11:13pm
It locked in the air. You had a known problem before your crash.

You are chasing your tail by fixating on the crash and the lever. It can lock up without even having a lever. Its just one part of the system. It needs to be fixed as per the suggestions above.

But what am I taliking about, this feels like a "much ty" repeating question loop, in multiple posts, where any suggestion is shunned.
imoto34
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9/8/2017 3:11pm
kzizok wrote:
It locked in the air. You had a known problem before your crash. You are chasing your tail by fixating on the crash and the lever...
It locked in the air. You had a known problem before your crash.

You are chasing your tail by fixating on the crash and the lever. It can lock up without even having a lever. Its just one part of the system. It needs to be fixed as per the suggestions above.

But what am I taliking about, this feels like a "much ty" repeating question loop, in multiple posts, where any suggestion is shunned.
I still haven't figured out the much ty thing. Seen you Harry and others use it heavy for awhile, care to fill me in?
kzizok
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9/8/2017 8:41pm Edited Date/Time 9/8/2017 8:48pm
kzizok wrote:
It locked in the air. You had a known problem before your crash. You are chasing your tail by fixating on the crash and the lever...
It locked in the air. You had a known problem before your crash.

You are chasing your tail by fixating on the crash and the lever. It can lock up without even having a lever. Its just one part of the system. It needs to be fixed as per the suggestions above.

But what am I taliking about, this feels like a "much ty" repeating question loop, in multiple posts, where any suggestion is shunned.
imoto34 wrote:
I still haven't figured out the much ty thing. Seen you Harry and others use it heavy for awhile, care to fill me in?
There is a troll that goes by many names and does the same thing as this thread. Wild goose chase of diagnosing a problem but never listening and perpetuating it. HuskyTamir, elkoz, etc.

Across the many accounts, one of the dead giveaways was him saying "much ty" or "much thank you", in an attempt at broken English.

So now, "much ty" is kind of the acknowledgement of, or to, the troll (or just being goofy). Of which we have with the case of the poopbutt.
Radfonz
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Location
AU
9/9/2017 1:49am
Make sure you have free play at the lever. If you don't have any, the transfer port may be closed. when the fluid heats up and expands, the pressure can't equalise therefore it will push against the pistons and apply the brake
kismith38
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Location
Buford, GA US
9/14/2017 5:03pm
Can you tell me what year and model your ktm is

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