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Fork Spring Rate - 215 lb Novice
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    JimDirt
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    by JimDirt » Sun Mar 29, 2015 9:51 pm

    OK if its not sucking back in when you pull it to full extension , then i would say the seal is good , as it would suck in farther and farther each pull/release

    I am thinking you are either not bleeding with the damper rod correctly by not getting all the bubbles out because your not opening up the valving when pulling on the rod , the valving needs to open to let the oil and air by , you need to give it a hard pull but a steady pull , if you pull too hard you will squirt oil out , if you do it right , it will open up the valving to let the air by , and you will see more bubbles , also make sure when your compressing it to bleed , don't let the valving get out of the oil , if you do then you sucked in more air

    Also , when pushing in the assembly , do it slowly and kind of rock it back and forth gently till it gets past the o-ring , if you add too much oil you will not be able to insert the assembly , it will go so far and just stop , basically hydro-locking , so just keep the oil at the level the book says , or just slightly above , making sure the rod is fully extended before pushing the assembly in

    Holding the cartridge upright and giving a slow but forceful push to get the assembly in , you should have to force it down , it should not just go in easily , then while pushing it in , get it to the threads and start twisting while still pushing to start threading it in , all the while pushing , do not let up until its about seated so it does not push back out and get air in , and also if you push it in too fast it can blow the oil out allowing air in before it seats
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  • mossman77
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    by mossman77 » Mon Mar 30, 2015 4:26 am

    That is pretty much what I've been doing. I'll give it another go this evening and keep a closer eye on the oil level as I'm bleeding. On my second attempt, I could feel the rod extending fully on its own when doing the initial 100mm vertical compressions, but when I proceeded with the full extensions oil came out of the bleed holes and then the rod no longer fully extended (-7/8"). I'll post back tonight.
    2007 CRF250X
    2004 CRF230F (sold)
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    JimDirt
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    by JimDirt » Mon Mar 30, 2015 5:52 am

    OK on the extension your letting it go , so it extends on its own , correct ??

    When your installing the assembly you are sure the shaft is fully extended before installing it , correct ??

    When you compress it , and let it go , each time , it should extend all the way ,every time , if you do it 10 times (just compressing it to see if it extends all the way) , it should still fully extend EVERY time , no matter how many times you compress it

    If it starts sucking back in , even if it only sucks in at first a little , and the more times you compress it , it sucks in a little more each time , and oil is still draining out when you tilt it with the hole down each time , then your seal is leaking , which would explain the excess oil coming out the holes when you tilt it , you will get some oil at first , which is why they tell you to tip it with the holes pointing down so it does drain off the excess from when installing the assembly , but if you keep compressing it , and you keep getting oil each time , then the seal is definitely leaking (the free Piston Seal) , which means you will have to take it apart , as shown in the pics i posted , and replace the seal

    Is it doing this with both rods , or just 1 ???


    And is it doing it the same length with both rods if it is , or are each extending differently ??

    If they are both doing it equally then i would say its something your doing while bleeding or installing the assembly

    If one ends up extending more than the other but they both keep retracting , or not extending fully and gets worse the more times you compress it , then the seals in both are bad
    2020 CRF450R
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  • mossman77
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    by mossman77 » Mon Mar 30, 2015 6:29 am

    OK on the extension your letting it go , so it extends on its own , correct ??

    The rod extends on its own to 11-1/4" when holding it horizontally and 12" when holding it vertically. Fully extended length is 12-7/8". I can pull it the remaining inch or so and it stays extended.

    When your installing the assembly you are sure the shaft is fully extended before installing it , correct ??

    Yep.

    When you compress it , and let it go , each time , it should extend all the way ,every time , if you do it 10 times (just compressing it to see if it extends all the way) , it should still fully extend EVERY time , no matter how many times you compress it

    Although it does not fully extend, it extends to the same point no matter how many times I pump it (11-1/4" and 12" depending on orientation). BTW, I am compressing the rod all the way as far as I can.

    If it starts sucking back in , even if it only sucks in at first a little , and the more times you compress it , it sucks in a little more each time , and oil is still draining out when you tilt it with the hole down each time , then your seal is leaking , which would explain the excess oil coming out the holes when you tilt it , you will get some oil at first , which is why they tell you to tip it with the holes pointing down so it does drain off the excess from when installing the assembly , but if you keep compressing it , and you keep getting oil each time , then the seal is definitely leaking (the free Piston Seal) , which means you will have to take it apart , as shown in the pics i posted , and replace the seal

    Oil stops coming out after several pumps and no additional leakage after a 10-minute 9" compression test.

    Is it doing this with both rods , or just 1 ??? And is it doing it the same length with both rods if it is , or are each extending differently ??

    I've only done one, but will do the other this evening to compare.

    If they are both doing it equally then i would say its something your doing while bleeding or installing the assembly

    Roger that.

    If one ends up extending more than the other but they both keep retracting , or not extending fully and gets worse the more times you compress it , then the seals in both are bad

    The first one is not retracting and extends the same length after multiple pumps.

    I have a novel idea, what if I used my vacuum bleeder to remove any trapped air? I could plug one of the bleed holes and attach my vacuum bleeder to the other. Or at least vacuum bleed the piston rod to ensure all the air is out of the rod and the oil before inserting the piston assembly.

    Other observations:
    - There is very little bubbling and no foaming of the fluid when pumping. Often times when I am pulling the rod out, it burps fluid out the top. Seems like that would mean it is fully bled, because otherwise air would come out.

    -When compressing the rod fully, I can hear some faint gurgling inside the rod chamber and also coming from the bleed holes at the top of the assembly. I replaced all the o-rings and want to say one of them appeared a tad bit skinnier. Maybe I'll try putting the old one back on.
    2007 CRF250X
    2004 CRF230F (sold)
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    JimDirt
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    by JimDirt » Mon Mar 30, 2015 9:08 am

    mossman77 wrote:
    OK on the extension your letting it go , so it extends on its own , correct ??

    The rod extends on its own to 11-1/4" when holding it horizontally and 12" when holding it vertically. Fully extended length is 12-7/8". I can pull it the remaining inch or so and it stays extended.

    Something is still amiss , as it should , no matter what , extend till it stops at the rebound piston , so either you are too low on oil while installing the assembly , or you are not bleeding it completely (i will follow up on this with one of your other comments)

    When your installing the assembly you are sure the shaft is fully extended before installing it , correct ??

    Yep.

    If the rod is fully extended when installing the assembly , then if its not after installation , then it means either not enough oil or it still has air


    When you compress it , and let it go , each time , it should extend all the way ,every time , if you do it 10 times (just compressing it to see if it extends all the way) , it should still fully extend EVERY time , no matter how many times you compress it

    Although it does not fully extend, it extends to the same point no matter how many times I pump it (11-1/4" and 12" depending on orientation). BTW, I am compressing the rod all the way as far as I can.

    Have you tried only compressing it so there is about 3 or 4 inches of the rod left exposed , in case you are getting air by compressing it all the way if the oil is low , or there is air in the system , doing this while holding the rod vertical

    If it starts sucking back in , even if it only sucks in at first a little , and the more times you compress it , it sucks in a little more each time , and oil is still draining out when you tilt it with the hole down each time , then your seal is leaking , which would explain the excess oil coming out the holes when you tilt it , you will get some oil at first , which is why they tell you to tip it with the holes pointing down so it does drain off the excess from when installing the assembly , but if you keep compressing it , and you keep getting oil each time , then the seal is definitely leaking (the free Piston Seal) , which means you will have to take it apart , as shown in the pics i posted , and replace the seal

    Oil stops coming out after several pumps and no additional leakage after a 10-minute 9" compression test.

    So your waiting 10 minutes , then compressing it , and it remains in the same extension as before , but still not fully extended , but also not any shorter ?

    Is it doing this with both rods , or just 1 ??? And is it doing it the same length with both rods if it is , or are each extending differently ??

    I've only done one, but will do the other this evening to compare.

    This will help confirm if there is a issue with either the install/bleed process or something else

    If they are both doing it equally then i would say its something your doing while bleeding or installing the assembly

    Roger that.

    If one ends up extending more than the other but they both keep retracting , or not extending fully and gets worse the more times you compress it , then the seals in both are bad

    The first one is not retracting and extends the same length after multiple pumps.

    But its not extending till it can go no further , and that bothers me and is not right , something is causing it to not extend fully as it should

    I have a novel idea, what if I used my vacuum bleeder to remove any trapped air? I could plug one of the bleed holes and attach my vacuum bleeder to the other. Or at least vacuum bleed the piston rod to ensure all the air is out of the rod and the oil before inserting the piston assembly.

    You can't vacuum bleed it because because if there is air in the system it is under the valving still , so unless its bled properly it won't lose the air that is there already

    Other observations:
    - There is very little bubbling and no foaming of the fluid when pumping. Often times when I am pulling the rod out, it burps fluid out the top. Seems like that would mean it is fully bled, because otherwise air would come out.

    If your still seeing ANY bubbles ,even if real small ones , then there is still air in the system , the oil should be absolutely bubble free , if there is 1 bubble , then there is air in the system , this part of the bleeding process is critical , there can be NO air bubbles period

    If the rod is burping the oil up so it splashes , then you just added air into the system , the oil should stay down and get nowhere near bubbling up if your bleeding the cartridge properly , remember i said before , if it squirts up , then your doing it too forcefully and quickly which is most likely adding air into the system , and at no time can the rebound stack ever come out of the oil or it will just suck air in and defeat everything you just did trying to bleed the air out





    -When compressing the rod fully, I can hear some faint gurgling inside the rod chamber and also coming from the bleed holes at the top of the assembly. I replaced all the o-rings and want to say one of them appeared a tad bit skinnier. Maybe I'll try putting the old one back on.


    If your hearing gurgling , then there is air in the system , if you hear oil flowing, that is ok , but if it sounds like its foaming or like there is air "gurgling", then there most likely is air and that is why the rod does not fully extend

    Again , the rod has to fully extend , if it does not , then you have to try it another way so your getting ALL the air out , if it does not suck in farther and farther each time and it does not continue to drain oil thru the drain hole , then the seal is ok , and its a install/bleed issue , that has to be remedied before you can go any further
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  • mossman77
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    by mossman77 » Mon Mar 30, 2015 9:26 am

    Have you tried only compressing it so there is about 3 or 4 inches of the rod left exposed , in case you are getting air by compressing it all the way if the oil is low , or there is air in the system , doing this while holding the rod vertical


    Yes, I did. That is what the manual said to do to purge any extra oil. A good amount of oil came out. I could feel the rod extending fully when I did this the second go around. It was only when I started doing full compressions that the rod began stopping short of full extension.

    So your waiting 10 minutes , then compressing it , and it remains in the same extension as before , but still not fully extended , but also not any shorter ?


    After installing the piston, pumping, etc., the last step in the manual is to compress the rod about 8" and hold it there for 10 minutes, then check to see if any additional oil comes out of the bleed holes. No additional oil came out, so that's a good sign.

    Sounds like it is best not to overfill with oil when bleeding the rod, because if it's overfilled after bleeding, I have to tilt the assembly to pour oil out, which is letting air in at the same time. Not sure I understand why vacuum bleeding the rod wouldn't work (before installing the piston assembly).
    2007 CRF250X
    2004 CRF230F (sold)
  • mossman77
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    by mossman77 » Mon Mar 30, 2015 10:51 am

    Correction, I am following the procedure in the Factory Service Manual no the owner's manual. The FSM includes a couple extra steps for checking the dampening rod travel and the 10-minute compression test. Other than that, the procedure is pretty much the same.
    2007 CRF250X
    2004 CRF230F (sold)
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    JimDirt
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    by JimDirt » Mon Mar 30, 2015 12:40 pm

    OK well then you will note that it says that the rod should extend to its "maximum" , if it does not , bleed it again , so i am still thinking you have air in the system , or the oil amount is not correct (drain it into a CLEAN pan , that way you can keep reusing the oil , as it should not be contaminated , so your not just dumping/wasting fresh oil)

    I know it shows to tighten the fork cap assembly in a vice laying sideways , but i prefer that you hand snug with the wrench , while holding the cartridge upright , so no air can possibly get in , then tip it and drain the excess out the weep hole , , now what i do to not have to sit there for 10 or whatever minutes , is to just take a rag and cover the area so the oil does not go everywhere and blow it out with a air nozzle

    I dont give the last snug check until i have the fork in the clamp on the bike and the bottom clamp snugged , i have never felt the need , nor do i know anyone that "torques" the fork cap assembly , a good quick hand snug is plenty sufficient , as the upper clamp holds it tight as well

    Again , this is after you can pump the rod and it extends FULLY every time

    I am still saying something is amiss in your bleeding procedure of either the assembly , or of the cartridge itself

    Again , if the seal was bad the rod would suck in farther and farther every pump and the oil would continue to drain from the bleed hole

    Did you watch the Race Tech videos on how to do the fork ?? , its more explicit than just reading , so you can see the procedure being done instead of trying to interpret what the text is saying to do

    The forks and shock are not hard to do , once you get the procedure down , i can tear them apart and re-valve and put it back together in about a hour , from on the bike , to back on the bike , its that simple

    The shock takes longer obviously since it takes longer to remove it than the forks
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  • mossman77
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    by mossman77 » Mon Mar 30, 2015 12:50 pm

    OK well then you will note that it says that the rod should extend to its "maximum" , if it does not , bleed it again , so i am still thinking you have air in the system , or the oil amount is not correct (drain it into a CLEAN pan , that way you can keep reusing the oil , as it should not be contaminated , so your not just dumping/wasting fresh oil)


    I haven't been draining it between attempts. I've just been adding more oil to bring it back to 47 mm above the piston seating surface.

    I know it shows to tighten the fork cap assembly in a vice laying sideways , but i prefer that you hand snug with the wrench , while holding the cartridge upright , so no air can possibly get in , then tip it and drain the excess out the weep hole , , now what i do to not have to sit there for 10 or whatever minutes , is to just take a rag and cover the area so the oil does not go everywhere and blow it out with a air nozzle


    That's what I've been doing.

    I dont give the last snug check until i have the fork in the clamp on the bike and the bottom clamp snugged , i have never felt the need , nor do i know anyone that "torques" the fork cap assembly , a good quick hand snug is plenty sufficient , as the upper clamp holds it tight as well


    I've been torquing it, but it doesn't budge much if at all, so my right arm must be calibrated to 20 ft-lbs :D

    Again , this is after you can pump the rod and it extends FULLY every time

    I am still saying something is amiss in your bleeding procedure of either the assembly , or of the cartridge itself

    Again , if the seal was bad the rod would suck in farther and farther every pump and the oil would continue to drain from the bleed hole


    I will keep trying. The only thing I can think of that I've been doing consistently wrong, is I've had to tilt the fork to pour out excess oil to achieve the 42 mm to 47 mm level prior to installing the piston, which is likely letting air back in. I'm assuming 42mm is the minimum so that air doesn't get back in and that more than 47 mm is fine, but results in more waste. Is that correct? Some videos online show the oil level just below the bleed holes, which results in a lot of waste.
    2007 CRF250X
    2004 CRF230F (sold)
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    JimDirt
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    by JimDirt » Mon Mar 30, 2015 3:47 pm

    You should not be pouring out anything , except AFTER you snug the cap to drain off the excess , the manual says how much oil to add (its like 6.5 oz or so) , with the cartridge drained , put in that much oil , then bleed the rod till there is no bubbles , then (if needed) , add a slight amount to get it to the level needed (about 1/4" above the rim of the rod chamber i believe , where it gets larger for the cap assembly) , then slowly install the assembly and that should be it , the rod should be fully extended , and when you pump it , it should fully extend on its own , and your done

    Hopefully [-o<
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  • mossman77
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    by mossman77 » Mon Mar 30, 2015 4:25 pm

    Manual says 42mm to 47mm above rod chamber. I'll be giving it another shot in a while here.
    2007 CRF250X
    2004 CRF230F (sold)
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    JimDirt
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    by JimDirt » Mon Mar 30, 2015 6:54 pm

    Put 6.5 ounces in it and it should be about right where it needs to be , then report back
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  • mossman77
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    by mossman77 » Mon Mar 30, 2015 7:28 pm

    Okay, I was extremely patient this time with the bleeding and the end result is the same (11-1/4" when horizontal and 12" when vertical). Reminder that full extension is 12-7/8". I know when the problem is occurring but I don't exactly know why. After bleeding and inserting the piston assembly, the rod extends fully after doing several slow 3.9" (100mm) pumps as instructed in the manual. I did about 7-10 pumps for each fork and they both returned to full extension. The next step is to compress the rods fully to expel any extra oil and that is when the problem starts. After a full compression (rod compressed all the way inside the cartridge), the rods no longer fully extend, presumably because the pressure is too great, oil is seeping by the piston, and air is getting in. SO, should I just skip the full compression step, or do I need to replace parts (I already replaced all the o-rings). The forks will never be compressed that much when on the bike anyhow will they? I noticed the illustration in the manual doesn't show the rod compressed fully so that the nut is up inside the assembly, so maybe they don't actually mean that far? I don't see how those two o-rings are expected to hold the oil back under that much pressure.

    I noticed quite a bit of contamination in the oil of one of the forks (the first one) and there has been small clumps of some silver substance on the piston assembly when I've taken it out the past hundred times (not really). Here's a pic of the substance (from deteriorating bushings?)

    Image

    And the questionable bushings:
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    2007 CRF250X
    2004 CRF230F (sold)
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    JimDirt
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    by JimDirt » Mon Mar 30, 2015 8:42 pm

    The bushing does have some wear to it , more than i would have expected , but that is not going to make it bleed off

    When your pushing the rod in , is the lock nut on the rod ?? , , the only thing i can think of , is when your pushing the rod in , that you are pushing the rebound stack out of the oil and getting air bubbles that way , if it does not suck in before you do that , then that might be the issue

    The rod not extending all the way is still a issue , it still should go the full distance if its sealing and you have enough oil in it , did you try what i posted using the 6.5 oz. , instead of measuring , and see if it makes a difference ??

    The rod should bottom out on the stack and be completely extended , this still does not make sense unless it does not have enough oil to fill the chamber
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    Weiser , Idaho
  • mossman77
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    by mossman77 » Mon Mar 30, 2015 9:13 pm

    Yes, the locknuts are installed. Now that you mention it, one of the steps in the procedure is to install the locknut and lightly seat it, which implies it should have been removed. Could the locknut be pressing in on something and letting air in?

    Yes, I emptied the chamber and filled it with 6.5 oz. of fluid and monitored the fluid level closely while bleeding, added a bit of oil to maintain 47 mm, etc. I bled each rod for about 15 minutes and there were absolutely no bubbles. Doing everything exactly by the book.

    Maybe the inner seals are in fact bad, and it only becomes evident upon full compression. In other words, the seals can't handle the increased pressure at full compression. Is this a possibility?
    2007 CRF250X
    2004 CRF230F (sold)
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