Front Brake Problems (long, sorry)

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kdxmaniac
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Post by kdxmaniac »

im saying that because i got shot down on here for saying that gravity bleeding works,{ wont mention any names} :twisted: .......... mechanic work is what i do for a living everyday, so i tend to find easier ways to do things......... guess gravity bleeding dont take 3-4 months afterall!!! :lol:..........i will say this tho..... pushing fluid BACK up into the master cylinder is a no, no.. :naughty: .... you are pushing old brake fluid and all the junk back into your master cylinder.... and you dont want to do that........what is the pupose of changing your fluid???
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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rbates9
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Post by rbates9 »

I happen to also be a mechanic so I know exactly what you are saying about doing it the easy way. :lol: I have done cars and trucks where the only way to do it is to sit back and wait. There is a special tool for every thing and a mechanics job is to find a way around it. :partyman:
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kdxmaniac
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Post by kdxmaniac »

got that right! :shh: ...we dont want to tell all our secrets... :lol:
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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Indawoods
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Post by Indawoods »

It's a closed system... what junk?

I'm glad the only 2 mechanics on the site found each other.... :roll: :mrgreen:
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****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
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rbates9
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Post by rbates9 »

SHHHHHH. Don't tell. :lol:

I work on heavy equipment, so the dirt bike thing is a little different and I have recievied a lot of help from this site. It's just that every one has there own way of doing things. What works for me might not work for you. But if I can find an easier way to do some thing I will.
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kdxmaniac
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Post by kdxmaniac »

what junk??? brake fluid goes bad, and draws moisture after a while...therfore, it aint gona last forever, and besides...... pushing it back up into the master cylinder is the WRONG way... you have a one way seal in your master cylinder, and it dont take kindly to fluid going the wrong way.........
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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Indawoods
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Post by Indawoods »

No... it's not a one way valve... it is a 2 way valve or else it wouldn't work.... Changing fluid is a hell of allot easier than charging a system too... completely different story....
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
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rbates9
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Post by rbates9 »

>|<>QBB<
Indawoods wrote:It's a closed system... what junk?

I'm glad the only 2 mechanics on the site found each other.... :roll: :mrgreen:
Just two?

I didn't meen to ofend the gods, just offering another aproach. :neutral:
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kdxmaniac
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Post by kdxmaniac »

quote="Indawoods"]

I have never had to tear into the KDX's master cylinders so I don't know much about them except they work....



2 way? howd you know? :hmm:
im not trying to start a fight........but sometimes there are easier, and faster ways to do something. i thought that what this site was for? i just cant figure out why i get shot down on here everytime i say something thats right, or easier......... no, i dont know everything, and if i dont know, then i dont pretend to.
Last edited by kdxmaniac on 10:15 pm Aug 11 2010, edited 3 times in total.
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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Indawoods
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Post by Indawoods »

Probably because there hasn't been any major updates to a simple plunger system since I have been alive... that's why...
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
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rbates9
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Post by rbates9 »

Settle down boys. :lol:
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turtle
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Post by turtle »

>|<>QBB<
Indawoods wrote:.... Changing fluid is a hell of allot easier than charging a system too... completely different story....
What is "charging a system"? Let's assume my system is completely dry, mostly because now it is :roll: . What does one do differently than if they were changing fluid (regardless of the method used :butthead: )
Bill
Central IL
2004 KDX220R
2011 Triumph Tiger 1050 SE
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Indawoods
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Post by Indawoods »

Changing the fluid is when I would do the gravity method...put a hose on the bleeder and route to a jar... crack the bleeder... pump the brake, add fluid, repeat.

Charging is when the system is completely dry... that is when I force it up the line....
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
gertie6car
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Post by gertie6car »

Interesting read!

I am just prepping my KDX having rebuilt it a while ago and put on a front end from a kx125.

I was unhappy with the routing of the front brake hose so I had another made up enabling me to use the same routing/fittings as the kx did. It looks great but, can I get a firm lever? Can I heck!

Manual bleeding in the time honoured fashion failed to get even a dribble at the caliper so I resorted to the reverse syringe method. This helped no end and within the first syringe of fluid being "injected" I had probably 60% firm lever. Unfortunately I cannot get it as firm as it ought to be. I have repeatedly tried injecting fluid via syringe and manual bleeding.

If I pump the lever repeatedly I get a firmer lever but I can still pull it to within 2"of the bars. The original set up was working as it ought so I have clearly got air in there somewhere.

I am not sure what to do now, any ideas would be helpful as I don't think I will pass the test with it like it is and I really want to hit some trails!!

All the best
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kdxmaniac
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Post by kdxmaniac »

just gravity bleed the dang thing! this method does work.
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
gertie6car
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Joined: 05:05 am May 17 2008
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Location: sunny surrey uk

Post by gertie6car »

Hi kdxmaniac,

I will have a go using this technique - seems straight forward enough for even me to manage!

Just seems too simple - will keep you posted.

Cheers!
gertie6car
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Location: sunny surrey uk

Post by gertie6car »

Mmmmm well the gravity bleeding is done but the lever is still spongy. Put half a litre through and still naff!

I know the original kx set up was good I bought a complete front end and could try it before fitting to the kdx. I have added a new front line and its gone to rat sh#t!

Anyone got any other ideas?

Thanks in advance

Gert
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kdxmaniac
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Post by kdxmaniac »

what kind of line did you have MADE UP....... the reason im asking, is because, if you dont have a high pressure line, then the line will "pump" or flex, and wont allow the pressure to push the caliper out enough. also, make sure you dont have any leaks.
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
gregp
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Post by gregp »

There is not a "two way valve" in the master cylinder, but there is a bleed port. When you release the brake lever, the piston comes back to a position that aligns a small groove in the plunger with a small hole in the master cylinder casting - allowing fluid to move up the line, and back into the reservoir. This is why one is able to push the brake pads (and pucks) back into the caliper. If this part of the system was clogged, once you applied the brakes, they would stay on. This is a common problem on many bikes, often manifesting itself as moderate to severe brake drag.
It is also possible to adjust the brake pedal, or lever to such an extent that the plunger can not return to align the bleed port. This is most common on rear brake systems, but I have seen it on front brake systems as well.
2004 Dual Sported KDX200
1999 Ninja 250 (Daughter's)
1996 DR 650 (stock, mostly street use)
gregp
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Post by gregp »

One thing that can help with bleeding brakes is to unbolt the caliper from the fork leg, and rest it even with, or slightly higher than the master cylinder. If you do not raise the caliper, it can be difficult to push the new fluid down the line because the air bubbles will continue to try to "float" upwards. The MightyVac sucks fluid very fast, so it can drag the bubbles down the line before they have a chance to float upwards.
If you use the MightyVac and you are getting bubbles, they are most likely being sucked in past the threads at the bleeder. If they are entering there, they will not affect the procedure.
2004 Dual Sported KDX200
1999 Ninja 250 (Daughter's)
1996 DR 650 (stock, mostly street use)
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