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Re-springing forks on a '05 CRF250R - cartridge question

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Was following the procedure in from the manual. All went as expected. Up to the point of reassembly. On one of the cartridge units, the cartridge rod will not stay fully extended. In fact, it's in a vacuum. When I manually extend the rod, it immediately retracts inward about 70-80%.

Other cartridge stays fully extended. I assume this one is correct.

At this point I decided to go a step further and take out the compression valve assemblies, drain and refill those as well.

So my question is at this point, what caused the one cartridge to pull a vacuum? Something the previous owner did perhaps?

Edited by tahoemike00
Adding clarification

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That's what I was afraid of. I read through that thread, but I did not see any mention of how to disassemble the compression valve (fork cap) assembly. I was able to get the valve and valve stack removed, but can't get the t-hat shaped piece removed. Special tool? It has 2 holes in it 180 degrees apart - maybe for a spanner type pin tool? It appears once that is removed, the body that holds the seal can be removed and the seal accessed.

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You can make a tool like this one that the Dogger (see his suspension Sticky in the CRF450R forums , good info) made , its basically a 16mm box wrench modified with a Roll Pin and cut down thinner to fit between the coils of the Pressure Spring (it is on top of everything just to show how the tool looks and works) make sure you turn your compression clicker all the way out before removing or assembling the assembly from the Fork Cap to avoid damaging the Compression Needle

cidpart2040307060900060.png

basevalve1.jpg

cidpart1060907010404050.png

cidpart4010206090107050.jpg

All you need to do is loosen the lock nut (shown in 2nd pic), and use a wrench made like that or a similar tool and remove the shaft (shown in the 3rd pic)

If its the Free Piston (shown by arrow in the 4th pic) seal it will leak out the 2 weep holes in the Cartridge assembly , if its the shaft seal (if the oil is leaking down the rod) you need to pull the cartridge rod out of the Cartridge ,

Edited by 450XJimDirt

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You can make a tool like this one that the Dogger (see his suspension Sticky in the CRF450R forums , good info) made , its basically a 16mm box wrench modified with a Roll Pin and cut down thinner to fit between the coils of the Pressure Spring (it is on top of everything just to show how the tool looks and works) make sure you turn your compression clicker all the way out before removing or assembling the assembly from the Fork Cap to avoid damaging the Compression Needle

All you need to do is loosen the lock nut (shown in 2nd pic), and use a wrench made like that or a similar tool and remove the shaft (shown in the 3rd pic)

If its the Free Piston (shown by arrow in the 4th pic) seal it will leak out the 2 weep holes in the Cartridge assembly , if its the shaft seal (if the oil is leaking down the rod) you need to pull the cartridge rod out of the Cartridge ,

Great, making progress. I now have the cap off and valve body (seal hosing) removed.

Reading the sticky thread in CRF450R forum - is there somewhere in the 163 pages of that thread that mention how to get the seal out of the floating valve body? :bonk:

(Yes, I have the retainer clip and backing washer removed) :smirk:

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You may have under-filled the cart too.

Pull the base back out...refill the damper, bleed it again...let the oil settle and then measure 1 7/8" of oil from the ledge inside the damper. A little more doesn't hurt. The excess will burp off the top.

If indeed the seals are bad in the cart, to get the lower one out, you need to drill the peen on the lower cap. Do this very carefully. You dont need to drill through (if you do the damper is toast), all youre trying to do by drilling the peen is to weaken the material enough so that it'll bend back out of the way so it'll unthread without damaging the threads. If youve got a hand operated drill..use that. Or put a drill bit in a pin vise and work it by hand.

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Reading the sticky thread in CRF450R forum - is there somewhere in the 163 pages of that thread that mention how to get the seal out of the floating valve body?

See the little clip in the one on the left? It comes out...that washer comes out, the seal is under there. You just pry it out....carefully!!!

kashima1.jpg

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You may have under-filled the cart too.

Pull the base back out...refill the damper, bleed it again...let the oil settle and then measure 1 7/8" of oil from the ledge inside the damper. A little more doesn't hurt. The excess will burp off the top.

If indeed the seals are bad in the cart, to get the lower one out, you need to drill the peen on the lower cap. Do this very carefully. You dont need to drill through (if you do the damper is toast), all youre trying to do by drilling the peen is to weaken the material enough so that it'll bend back out of the way so it'll unthread without damaging the threads. If youve got a hand operated drill..use that. Or put a drill bit in a pin vise and work it by hand.

The cart. was hosed when I removed it to do a spring rate swap. The cart. acted like a screen door closer. The rod would retract almost all the way back in by itself after manually extending.

So either A: The previous owner underfilled the cart to begin with, or B: the seal is blown.

It's carts are totally apart now, with the exception of the seal out of the floating valve body and I just ordered new seals. So I am committed.

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See the little clip in the one on the left? It comes out...that washer comes out, the seal is under there. You just pry it out....carefully!!!

Yup! The clip and washer are out. I didn't want to get too aggressive trying to pry the seal out. It looks like a steel sleeve encased with the rubber seal material around the metal, so I didn't think it would pry out like a regular 'Gumby' rubber only seal.

I figured if I tried to pry it out, the seal would cock and jam. Not wanting to hose this housing at this point in the process.

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Some one on the suspension site had posted a picture of a tool he had made to remove the peening of the cartridge. It was a tubeig cutter with the cutting wheel replaced by a bearing. the tool is repeadly run around the peening which will relieve the peening. If you do a search you may be able to find the post.

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What Brian (the Dogger) told me was to heat up the piston slightly (since the seal is bad anyway you cant hurt it removing it) and then it will come out easier (remove the bushings first) , i did not find it wanting to come out any easier heated than it did cool , so when it cooled off to where i could casually hold the piston (it was not red hot , but warm enough it was hard to hold onto) i just used a thin screwdriver and pried it out , i have not got a replacement yet as i did this on a old Fork Cap Assembly i had for practice before i went and did it on my bike , when i do order the seals i now know how to do everything properly , as my bike does the same as yours on one side , but i have just been riding it because i have not had the extra cash to get the seal and a few other internal parts i want to swap (the shafts in my pic #3, as well as some other things) , to make my suspension even plusher than it is now

But since you are replacing the seals , it does not matter if you damage them , if it was leaking already then it is no good anyway , i would recommend replacing both as if one went bad the other will soon follow , since that is what happened to me before , i replaced the entire Fork Cap Assembly last year , now the other side started leaking , so i could have avoided this by doing both last year

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What Brian (the Dogger) told me was to heat up the piston slightly (since the seal is bad anyway you cant hurt it removing it) and then it will come out easier (remove the bushings first) , i did not find it wanting to come out any easier heated than it did cool , so when it cooled off to where i could casually hold the piston (it was not red hot , but warm enough it was hard to hold onto) i just used a thin screwdriver and pried it out , i have not got a replacement yet as i did this on a old Fork Cap Assembly i had for practice before i went and did it on my bike , when i do order the seals i now know how to do everything properly , as my bike does the same as yours on one side , but i have just been riding it because i have not had the extra cash to get the seal and a few other internal parts i want to swap (the shafts in my pic #3, as well as some other things) , to make my suspension even plusher than it is now

But since you are replacing the seals , it does not matter if you damage them , if it was leaking already then it is no good anyway , i would recommend replacing both as if one went bad the other will soon follow , since that is what happened to me before , i replaced the entire Fork Cap Assembly last year , now the other side started leaking , so i could have avoided this by doing both last year

Hey thanks for the reply. I finally got that booger out of there. I knew I was going to replace the seals anyways, I had no fear of trashing the existing seal. What made me nervous was trashing the floating valve body itself. Easy to gouge aluminum and plenty of critical sealing surfaces that could easily be damaged.

I too went the route of removing the split bushings and the o-ring then heated it up. Hot potato! And it did no good, couldn't hang on to it anyways. I had to really get after it to get it out. I did ding and mar certain areas, but none of the critical surfaces. Nothing a little jewelers file and emery won't dress up.

I ordered 2 each of the seals to do both fork legs, upper and lower. I figure if I have them torn down this far, might as well take care of all of the cart. seals!

Edited by tahoemike00
Spelling as usual.

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Do you have the new seals yet? Are they really stiff like rubber molded around metal?

If there is rubber between outer dia. of seal and the valve,maybe you could nudge it out with some sort of "J" shaped tool. That circlip used there makes me think that the seal alone is not tight enough to stay in place on it's own during operation.

Oops didn't see that last post,,,sorry.

Edited by MAICOBILL
add on

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When you do the lower (it wont matter when you take it apart) make sure to wrap Teflon tape around the threads , so when you put the shaft back in , you dont ruin the new seal , also go real slow and careful with that step , as mentioned there is some info on the peeing here http://www.thumpertalk.com/forum/showthread.php?t=969601

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Do you have the new seals yet? Are they really stiff like rubber molded around metal?

If there is rubber between outer dia. of seal and the valve,maybe you could nudge it out with some sort of "J" shaped tool. That circlip used there makes me think that the seal alone is not tight enough to stay in place on it's own during operation.

Oops didn't see that last post,,,sorry.

When I saw the circlip and washer, I thought the seal would slide right out once the clip was removed. No go. That seal is press fit. Tight.

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When you do the lower (it wont matter when you take it apart) make sure to wrap Teflon tape around the threads , so when you put the shaft back in , you dont ruin the new seal , also go real slow and careful with that step , as mentioned there is some info on the peeing here http://www.thumpertalk.com/forum/showthread.php?t=969601

Got it - great tip!

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All good information and pics in this thread :bonk:

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