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damper rod not full extending

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On my 2006 CRF250R I am servicing my forks (changing oil/seals). This is a new bike to me so I don't know its history other than it would be my guess that the fork oil has never been changed (from my judgement of guy I bought it from, the fact that the forks seals were leaking as well as the fork oil looking very, very old/dirty/dark when I poured it out).

In any event, I removed all oil and thourougly cleaned all parts. The teflon bushings all look good as did the other internal parts (I am not an expert on suspension service - just following manual and various how to videos and have changed fork oil/seals successfully in the past on other bikes).

I disassembled/removed the damper rod and properly cleaned it and the reassembled the damper assembly, added oil, installed cartridge, and bled damper.

What is happening is after I depress the damper rod it does not fully extend back out of the damper on its own as it should - it hits a sticky point with approximately 3.5" or damper rod still inside the damper cartridge. To get the last 3.5" to fully extend, I have to help it manually past the "stick" point.

Additionally, I noticed that the rod hit this same stick point before I even disassembled it (I tested it before I drained the oil from the damper assembly). Also, both fork dampers (each side) is doing the exact same thing - both before disassemnly and after I cleaned everything, added new oil, bled and reassembled.

What could be causing this problem and how do I fix it?

Thanks in advance for your help.

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Thanks but I was under the impression that maybe 1/2" to 1" of rod not extending on it's own was normal but not 3.5".

Maybe it is normal as it is??

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sorry, re read your post, try polishing the rod of the one that sticks with a scotchbrite pad, rebleed

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Thanks but I was under the impression that maybe 1/2" to 1" of rod not extending on it's own was normal but not 3.5".

Maybe it is normal as it is??

it would be normal if you have shorter ICS springs or increased stiction.

what happens if you pump the rod (entire stroke) 20 or 30 times? does it extend the same amount? then at least your seals should be ok

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I repaced the stock presuure springs (1.9) to one step lighter springs (1.61) but the new, lighter springs were the same length as the old springs and the same sticking was happening before with the old, stock springs.

Will the rod "polishing" with scotch brite damage theh coating on the rod? Where it is stoicking there does not appear to be any "rough" spot causing the rods to stick.

I will try the pumping thing first and see what happens - this would only confirm that the rod seals are OK - correct?

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I will try the pumping thing first and see what happens - this would only confirm that the rod seals are OK - correct?

if the seals are leaking the rod would not extend that far, right.

but usually a vacuum is created then, so if you pull the rod completely it will move back an inch or so

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When I pull the rod out it does not suck back in. Only problem I am having is that the rod does not fully extend on its own.

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on KYB forks you can see the position of the free piston through the bleed hole.

then when you remove the BV assembly you know how much preload you have.

don't know if this is possible with showas, but when the preload would be too little, the rod could not extend completely.

just a guess...

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It's the lighter pressure springs, or at least they aren't helping the situation. Less pressure on the oil means less extention pressure on the rod. A more reactive cartridge = more chance of cavitation due to less pressure on the oil.

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As long as the seals are not leaking, it is more than likely a film has developed on the lower rod were the oil sits. You will see a haze on the rod when it is dry. You need to remove the haze. You only want to as aggressive as is needed to do the job. I can usually get it with by putting the damping rod in the lathe and using some wet 2000 grit followed up with fine crocus cloth.

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Got it fixed. I noticed a slight haze on the rod as mentioned, I then lightly used some fine scotchbrite and now everything works perfectly - the rod fully extends smoothly on its own.

Thanks everyone for your input.

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