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bleeding the clutch (with brake fluid)

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Does it matter if i use dot 4 or 5.1 brake fluid, arent they the same just with different boiling points?

On the clutch perch on the bike it says to only use DOT 4 fluid, but in the manual it says to only use DOT 5.1 fluid, so which one do i use?

(the bikes a 2009 250sx)

if i used dot 4, then i could use the rest later in the brakes aswell and on my dads and brothers bikes if they needed it. would it matter if i put in whatever i put in and there was still some of the other stuff?

also, whats up with the reverse bleeding with the syringe? do i need a bleeding kit, or just the fluid. im doing this because i destroyed the cable and need to replace it. :ride:

thanks in advance:thumbsup:

mike.

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It doesn't really matter. Yes-dot 5.1 has a higher boiling point, but you can use both.

Reverse bleeding is more effective at forcing air out of the system, vs. say bleeding a brake line. You don't need the fancy KTM bleed kit, just a syringe and a piece of ruber tubing. A second set of hands is very helpful during the bleed process, since you'll need to symphon off extra fluid from the clutch reservoir-helpful to have a second syringe handy for this too.

-Scott

Does it matter if i use dot 4 or 5.1 brake fluid, arent they the same just with different boiling points?

On the clutch perch on the bike it says to only use DOT 4 fluid, but in the manual it says to only use DOT 5.1 fluid, so which one do i use?

(the bikes a 2009 250sx)

if i used dot 4, then i could use the rest later in the brakes aswell and on my dads and brothers bikes if they needed it. would it matter if i put in whatever i put in and there was still some of the other stuff?

also, whats up with the reverse bleeding with the syringe? do i need a bleeding kit, or just the fluid. im doing this because i destroyed the cable and need to replace it. :ride:

thanks in advance:thumbsup:

mike.

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I thought brake fluid ate the seals on the clutch side? you have to use the exact type it calls for

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I guess you don't believe what I already posted to you in the KTM section, that you can safely use DOT 3, 4, or 5.1 with no problems. Maybe you don't believe what Brembo cast right into the M/C cover. Maybe you believe what one uniformed poster told you, to NEVER EVER use DOT 3, 4, or 5.1 and to only use Motorex 5.1

Okay, since you still are a doubter, check this link:

http://www.frsport.com/ATE-Type-200-DOT4-Amber-Racing-Brake-Fluid-1L-Compatible-DOT3-4-5-1_p_1280.html.

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I thought brembo cast the wrong label on some

the difference is if the fluid contains silicone, some require it, some don't, I think the manual is the one to go with, incorrect fluid causes the seals to swell and fail

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Only Dot 5 contains silicone and should not be used in the brembo system.

The older ktm hydraulic systems used mineral oil, the newer brembo systems use regular old brake fluid-DOT 4 or DOT 5.

By the way-all of this is documented in your KTM owners manual, which are downloadable on the KTM site.

-Scott

I thought brembo cast the wrong label on some

the difference is if the fluid contains silicone, some require it, some don't, I think the manual is the one to go with, incorrect fluid causes the seals to swell and fail

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I've heard of guys using fork oil, and ATF instead of brake fluid

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Dot 3, 4 and 5.1 are all glycol based and are interchangeable FROM A CHEMICAL STANDPOINT. I doubt there's a boiling problem in a clutch actuator so I would have no problem with using any of those.

Dot 5 is the silicone fluid as was stated. In compatible with the glycol fluids. Might be ok with the rubber after flushing out all the old fluid.

ATF? It would work until it attacked the rubber. Water would work too for a while. Doesn't mean you should use it.

Edit: Some clutch systems call for mineral oil. ATF might work there. KTM's for instance as RR stated above.

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Dot 3, 4 and 5.1 are all glycol based and are interchangeable FROM A CHEMICAL STANDPOINT. I doubt there's a boiling problem in a clutch actuator so I would have no problem with using any of those.

Dot 5 is the silicone fluid as was stated.

ATF? It would work until it attacked the rubber. Water would work to for a while. Doesn't mean you should use it.

why would atf attack the rubber? it's used in transmissions with rubber seals

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Depends on the rubber.

Brakes used to use natural rubber and mineral oils would eat it. They probably still do. Transmissions use something like viton.

Note the last paragraph I added. Maybe that's why you heard what you heard

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ok, so ive got the clutch pipe/tube/cable and some motorex DOT 5.1 Brake fluid, so i should be right, just need a syringe, some clear plastic tube and some help from dad.

only thing i could use now would be a some help with the reverse bleeding procedure :ride:

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Mikekx, All the steps are outlined in the owners manual. If you don't have a copy, they're available for free download from the ktm site.

Steps.

1. Stand bike up on milk crate (or other device) so that the bike is sitting level.

2. Remove clutch reservoir cover.

3. Drape a shop towel/rag around the clutch reservoir to catch any spilled brake fluid

4. Remove rubber stopper on top of the slave clutch bleeder bolt.

5. Insert spanner over the bleeder bolt.

6. Draw brake fluid up into syringe, making sure no air is left in the hose or syringe.

7. Place syringe hose onto the end of the cluch slave bleeder bolt

8. Open the bleeder bolt, then push syringe and fluid through the bleeder bolt, close bleeder bolt. Draw out excess fluid from clutch reservoir with a second syringe.

9. Repeat step 8 until you no longer see air bubble coming out of reservoir.

10. Reinstall clutch reservoir cover and rubber bleeder bolt cover.

A few notes:

Brake fluid eats paint and damages plastic. Use care and make sure to avoid getting any on your bike during the process. Clean up an spills immediately.

To help free air trapped in the line, have someone tap the clutch line with a spanner wrench when you're forcing fluid through the line.

Hope this helps.

-Scott

ok, so ive got the clutch pipe/tube/cable and some motorex DOT 5.1 Brake fluid, so i should be right, just need a syringe, some clear plastic tube and some help from dad.

only thing i could use now would be a some help with the reverse bleeding procedure :ride:

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I've heard of guys using fork oil, and ATF instead of brake fluid

Fork oil and ATF in the earlier Brembo clutch systems that specify mineral oil is fine. In the newer ones that specify DOT 4 or DOT 5.1 then that is what should be used. DOT 4 and DOT 5.1 can be mixed with no ill effects. DOT5 is the one to avoid.

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ok, so we tried to bleed it 3 times this afternoon, all unsuccessful. we tried bleeding it down the system and thought we had it right untill i started my bike and tried to use the clutch, but i pulled in the clutch and nothing happened. so then we tried bleeding back up the system and it didnt work either.

we were using a small syringe joined to a small piece of clear tube with a zip-tie. the fluid just leaked out of the join whenever dad applied pressure to the syringe, so we're trying to buy one of the expensive :ride: ktm "special tool" ones.

How are you supposed to do it???

we tried bleeding down the system with no luck, then tried bleeding up the system so that he locked off the bottom and i squeezed in the clutch lever, then he opened it and tried to force brake fluid in as i let the lever out and then he lock the bottom while i pull the lever back in.

this didnt seem to work, but that could have just been the syringe and the leaky join.

we also tried bleeding from the bottom up with the clutch lever out, that definately didnt work.

HOW ARE WE SUPPOSED TO DO THIS??

3 hours and all we acomplished was changing over the clutch cable/pipe.

could someone please explain how to do this properly :ride:

Thanks, Mike. PS: the manual sucks and doesnt say anything about the lever position while bleeding up the system.

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I prefer top down, using the clutch lever to pump fluid down into the line, and I use a 1 way airline valve from a fishstore, petsmart/petco sells them, along with some airline, you loosen the bottom bleeder and pump the fluid in, the one way air valve will let fluid out, but wont let air back in.

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ok, so we tried to bleed it 3 times this afternoon, all unsuccessful. we tried bleeding it down the system and thought we had it right untill i started my bike and tried to use the clutch, but i pulled in the clutch and nothing happened. so then we tried bleeding back up the system and it didnt work either.

we were using a small syringe joined to a small piece of clear tube with a zip-tie. the fluid just leaked out of the join whenever dad applied pressure to the syringe, so we're trying to buy one of the expensive :ride: ktm "special tool" ones.

How are you supposed to do it???

we tried bleeding down the system with no luck, then tried bleeding up the system so that he locked off the bottom and i squeezed in the clutch lever, then he opened it and tried to force brake fluid in as i let the lever out and then he lock the bottom while i pull the lever back in.

this didnt seem to work, but that could have just been the syringe and the leaky join.

we also tried bleeding from the bottom up with the clutch lever out, that definately didnt work.

HOW ARE WE SUPPOSED TO DO THIS??

3 hours and all we acomplished was changing over the clutch cable/pipe.

could someone please explain how to do this properly :ride:

Thanks, Mike. PS: the manual sucks and doesnt say anything about the lever position while bleeding up the system.

You may find that the bleed nipple is blocked - this is what happened with my. I removed master cylinder lid, attached tube and syringe to bleed nipple, cracked bleed nipple open, squeezed syringe and nothing. Just oil leaking out the join between syringe and nipple. So I removed nipple completely and tried to blow through it and found it completely blocked. Cleaned it with wire and water, dried it, replaced, and all fine - bled through easy as anything.

Pete

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The seals around the syringe to tube and tube to bleeder nipple need to be airtight/snug. Rubber surgical style hosing is best. Plastic hosing is likely too stiff and loose to keep air out.

You shouldn't need to even touch the clutch lever when you bleed upwards.

Tapping on the clutch line during the process also helps release trapped air in the line, which typically occurs at bends and joints.

-Scott

ok, so we tried to bleed it 3 times this afternoon, all unsuccessful. we tried bleeding it down the system and thought we had it right untill i started my bike and tried to use the clutch, but i pulled in the clutch and nothing happened. so then we tried bleeding back up the system and it didnt work either.

we were using a small syringe joined to a small piece of clear tube with a zip-tie. the fluid just leaked out of the join whenever dad applied pressure to the syringe, so we're trying to buy one of the expensive :ride: ktm "special tool" ones.

How are you supposed to do it???

we tried bleeding down the system with no luck, then tried bleeding up the system so that he locked off the bottom and i squeezed in the clutch lever, then he opened it and tried to force brake fluid in as i let the lever out and then he lock the bottom while i pull the lever back in.

this didnt seem to work, but that could have just been the syringe and the leaky join.

we also tried bleeding from the bottom up with the clutch lever out, that definately didnt work.

HOW ARE WE SUPPOSED TO DO THIS??

3 hours and all we acomplished was changing over the clutch cable/pipe.

could someone please explain how to do this properly :ride:

Thanks, Mike. PS: the manual sucks and doesnt say anything about the lever position while bleeding up the system.

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I've heard of guys using fork oil, and ATF instead of brake fluid

Not with any success they didn't. The clutches that call for mineral oil can use fork oil or atf. The clutches that use brake fluid have to have brake fluid. It can be Dot 3, Dot 4, or Dot 5.1 just not Dot 5

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Not with any success they didn't. The clutches that call for mineral oil can use fork oil or atf. The clutches that use brake fluid have to have brake fluid. It can be Dot 3, Dot 4, or Dot 5.1 just not Dot 5

obviously it was the mineral oil older ktm's, but I'm sure you knew that already

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One of the problems with bleeding the slave cylinder is unlike the brakes, there is no positive stop. On brakes your brake pads squeeze the brake rotor which limits the amount of travel. Try removing the slave cylinder and carefully clamp it in a vice. Now when you pump the lever and open the bleed screw you will actually be doing something.

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