How To Replace Fork Seals on WP XACT AER Motorcycle Forks

hey i'm charles with rocky mountain atvmc and if you have fork seals that are leaking oil i'm going to show you how to get those fixed on the wp exact aer forks the bike we're working on today is a 2020 husqvarna fc 450 and it's got the exact aer forks on it these are just updated aers now you can find these forks on 2020 and newer husky and ktm dirt bikes now it's still going to be a similar process to just the plain old aers but whatever bike you're working on you want to refer to your model specific service manual throughout the process now if you're not sure if you have the same forks as us one way to check is look at the fork caps the left fork you're gonna have a schrader valve on it and the right fork you're gonna have a compression adjuster so if you have the same forks as us and your fork seals are leaking then let's go ahead and get them swapped out for parts we have our fork and dust seal kit from tusk our suspension cleaner some race tech seal grease and some fork oil to do this job we're going to use some safety glasses rubber gloves rags we have our 48 millimeter fork seal driver a seal bullet you're going to need two different wrenches for the fork cap so one is for the outer portion of the fork cap and then this one is for the inner portion other than that we're going to use some common hand tools including a torque wrench make sure you have a small screwdriver or pick we're using a heat gun ratio right drain pan we have our tusk digital suspension pump and a pen and paper to write things down throughout the process now the specific sizes on these sockets are a 22 millimeter 19 17 and a 10. the first thing we're going to do is remove our front wheel our brake caliper and our fork guards the next thing we need to do is remove the fork now one thing i do want to point out is if you guys don't have a suspension vise you're going to want to loosen up this fork cap as soon as you loosen up the upper triple clamp now to do that on some bikes you might actually have to pull these handlebars back to fit this fork cap wrench on there once everything's loosened up you can remove your forks now with the forks on the bench we're going to finish cleaning these forks off we did hose the bike off earlier but it didn't get everything off obviously and one thing to note with these you also want to check your brake pads make sure there's no oil on those and get them replaced at the same time if there is any oil on them now to do this we're just using the suspension cleaner and a rag now and one more thing i do want to point out the really critical areas to have clean are just around this dust seal then on the bottom sometimes you'll get some dirt caked up in there and then obviously up by the fork cap make sure all that stuff is clean and then i actually like to inspect this fork tube for any nicks well the fork is still together and that way if i need to file down a nick or use a little emery cloth to clean it up or scotch brite whatever you have you can do that now and it's not going to get all over the internals and spray that stuff off once you're cleaned up we're going to start with the left fork and there's two checks you can make you can loosen the bleeder screw and make sure there's not excessive pressure coming out from there that can let you know if that inner air chamber is bad if it is we have a separate video on how to fix that chamber so start by checking that so i removed the screw and i didn't have any air pressure escape so we know that's good now i'm going to remove the valve stem cap you can check the pressure or just remove that valve core we're going to check the pressure just so we get it back to the same setting as we had before all right so we've checked our pressure make sure you write that down and then before you remove that valve core you always want to release any pressure from it once it's released then you can remove that core now we're going to loosen up the fork cap and then we'll drain all of this fork fluid into our drain pan and one thing you might notice is we have a little bit of oil coming out of this bleed hole right at the top just make sure that's facing down once we have the fork oil drained out for the most part we're going to temporarily reinstall the fork cap now we're going to clamp our lower portion of the fork tube in our vise and throughout this process you want to make sure you're using a vise with soft jaws or if you have to maybe you can get a couple of blocks of wood in between this or some heavy rags to hold this in place just make sure you don't damage anything now we're going to loosen up this blue bolt with our 19 millimeter socket now one thing to help you get this bolt loosened and all the way out is i did press down on this fork tube a little bit that's going to press down on that cartridge and let this bolt come all the way out so with that center bolt out what we're going to do is loosen this cap all the way off and then we can remove that complete air chamber so i'm just going to be sliding this outer tube all the way down the air chamber is going to pull out we're going to set this aside now again at this point we're not going to be doing anything else with this air chamber so if you need to know how to fix anything on this be sure to check out that video from here all we have to do is we're going to separate the outer tube from this inner tube and you know if if this guide is worn out for that fork guard then you can replace it but ours is fine so we're just going to leave that we're going to pop our dust seal down so we're going to use a screwdriver to get in between here and then we're going to twist the screwdriver sideways you can take a couple of small bites that way you don't damage your fork tube we'll slide that down and then we're gonna have a clip just inside here to remove it we're gonna use a flat blade screwdriver and a pick you've done that you can heat this surface where your bushing rides inside the outer fork tube and then we're going to use both fork tubes as a slight hammer and pull them apart now that they're apart we're going to remove our top bushing and as you take things apart make sure you pay attention to the orientation of everything so this has a teflon coating on it you want to make sure that's in good condition if this is worn through you're going to have a copper appearance underneath it and you'll want to get it replaced you have one more bushing and the teflon on this one is just on that inside you'll make the same inspections and we have our backup ring we'll lay that out and then the fork seal so this is our oil seal you'll notice that the spring is facing towards the bottom of the fork so keep that in mind when you're going back together then we've got our retaining clip and our dust seal i'm going to go ahead and take the new fork seals and lay them in the correct orientation now before we go back together we're going to clean everything up with the suspension cleaner and this clip i'm just going to wipe it off with a rag same with the backup ring and then everything else but the seals is going to get sprayed off now a few things to pay attention on this outer tube are make sure these threads are cleaned up really good and then down where the clip goes into make sure all that's nice and clean and then you're going to look for any dings in the side of this so if you've laid it over in some rocks and have a ding in there your fork tube actually might get caught on that and if that's the case you might have to replace this now for the inner tube we're going to check it one more time for any nicks or dings make sure your fingernail doesn't catch on anything so this one's looking good when we spray this out a lot of junk will build up towards the bottom so make sure this area down here make sure you spray it out really well once everything is cleaned up you can start going back together so we have this 48 millimeter fork seal bullet now there's a little lip right here where that bushing normally sits you don't want that to cut your fork so so that's why we're using the seal bullet if you don't have one of these you definitely want to at least use some tape you can use painters tape that's going to cover it up good and then i'm going to apply a little bit of fork oil to the sill bullet and the fork tube just to help everything go on smooth and if you noticed we didn't remove the o-ring that's going to indicate how much fork travel we used if you took that off make sure you put it back on so we're just going to use some seal grease just a little bit inside of the dust seal slide that down don't forget your retaining clip next we can apply some grease to our fork seal this is seal grease this is a lot lighter than your standard grease and then again we have the spring facing the bottom of the fork and you know this open side it's going to be facing up we also have that garter spring around the top inside it just looks a little bit different and the only reason i mentioned that is some aftermarket seals not might not have the garter spring on this lower portion like ours does so we've got that in place now we need to remove this bullet you're going to want to install this backup ring then we have our bushing i'm going to apply some fork oil to that and we have that second bushing push that on make sure it snaps into place and then we can slide this outer fork tube on so at this point we need to get our 48 millimeter fork seal driver out and then before we drive this into place i like to heat up this fork tube again now one thing before i remove this from the vise we have this bushing i'm going to set it into place by using half the driver on that backup ring so that's in place i'm gonna get that fork seal close to where it needs to be go ahead and flip this up now this tube is not crazy hot but it is definitely warmer it's about what you want and then sometimes you know if it's warm enough you can press that right in if it's not you're gonna have to take a couple hits so we have that pitch change and then i have that retaining ring groove fully exposed now we can install the retaining ring into its groove and we'll use a screwdriver to help push it all the way down into place all right now we need to install the dust seal so i'm just going to lower this inner fork tube down and press on it and we've got our dust seal installed so now we're going to put this bracket for our brake caliper back into the vise and we're going to reinstall the air chamber now with this one thing i want to point out is the bottom of this needs to line up in the slot of this axle holder so make sure you have that in the correct orientation and to help line that up i'm going to use a finger and you can fill it you can rotate that air chamber and it's just going to drop into place you should be able to see those blue threads all the way to the bottom now we can lube up this o-ring on our bolt then we're going to install it make sure you press down on that air chamber while you screw this into place and then we're going to torque it to 33.2 foot-pounds now you can remove the fork from the vise we're going to fill this with oil now the standard spec for ours is 220 milliliters we can go 20 milliliters more or 40 millimeters less than that spec we're just going to use the stock spec then once you've done that you can go ahead and screw on the fork cap i'm going to put the fork back into our soft jaws we're going to go ahead and snug this cap up you're going to want to refer to your service manual for the correct torque now we can reinstall that schrader valve and with this we had 141 psi in there when we took it apart i'm just going to reset it to that the minimum on ours is 102 psi to 174. so you can be anywhere in that range whatever you prefer all right once you have your pressure set we'll reinstall this cap now one thing to point out you can either do this before you go ride or if you're just going to throw it on and go ride make sure you open this bleeder one more time because when you pump this up chances are that that outer or that inner tube extended a little more and you just want this chamber to be at atmospheric air pressure so that's looking good on ours we're ready to get the other seal installed now we're ready to move on to this right fork now the first thing we need to do with it is record where the compression and rebound adjusters are so we're just going to turn them all the way clockwise in you'll count the clicks so this one's 12. i'm going to write that down and then i'm going to back it all the way out counterclockwise and that's going to help with the bleeding process in a later step now we'll do the same thing on the rebound so this one's 15 out so i'll write that down and back it all the way out counterclockwise now one other thing i want to point out about this fork is a question i get asked a lot and it's about the spring pressure so there is no spring in this one it just has atmospheric air pressure in here and it will act a little bit as a spring but it's going to be really soft and that's totally normal to have your fork like that so we're going to take that we're going to clamp it in our suspension vise jaws and we're going to loosen up this fork cap and then while we're here i'm actually going to loosen an inner cap on the fork cap i'm going to loosen that up with our special tool so for now i'm just going to loosen that up a little bit and we can finish unscrewing the fork cap and we're going to lower these this outer tube and dump the fork oil then we can slide up this outer tube and we'll temporarily install this fork cap again and then the axle clamp we're going to clamp that into our soft jaws now these next few steps are going to be similar to the other fork we're going to use a 22 millimeter socket to take out this bolt on the bottom now once you've done that you can lower this outer tube and then you can remove this inner cartridge now we can remove the dust seal with our screwdriver then we have that retaining clip then we'll heat up the outer tube on the bushing and then we can slide hammer these apart all right now we're going to take care of this damping cartridge so with this if your bike has 30 40 hours of use on it it's not a bad idea to change out the oil that's in here but one thing you want to pay attention to is how this works so you can see if you press on this the rod extends all the way on its own and that's what this is supposed to look like so when you go back together with it after you bleed everything out you need to make sure that this damper rod acts exactly the same way as when you took it apart i'm just going to be real light with the clamp so now we can take the fork cap tools and we're going to remove this inner cap so that popped up a little bit on its own to get it the rest of the way out make sure you have the drain pan underneath it and then i'm actually going to push up on the damping rod and it's going to help push this cap out and that's as far as it pushed that cap up so we're just going to rock it out the rest of the way so all the o-rings and rubber pieces you want to inspect them for any damage or cuts if you see any damage make sure you get those replaced so now we can take the cartridge and we're going to dump all the oil out and you can pump this rod back and forth and that's going to help get all the remaining oil out so now we can fill this tube up with 380 milliliters of oil i'm also covering up the hole in the side of the tube with my thumb now to get this blood up we need to pump that piston rod up and down until you can feel there's no more air in there and you still want to let this sit for a little bit and let any bubbles work to the top that's why we're doing this before we get all these seals replaced so at this point we need to let this cartridge sit for maybe 15 minutes and let any bubbles rise to the top that way you're not going to have to re-bleed this later on now one thing to check is these threads right here make sure they're nice and clean if they're dirty you definitely want to get those wiped out now we can continue with replacing the fork seals so i'm going to remove that upper bushing the lower bushing backup ring oil seal spring retainer and the dust seal and just like the other fork we're going to go ahead and clean all these parts up all right now we can install this compression damping assembly now to do this i've pushed that push rod up just a little bit you want to make sure you definitely don't push any oil out of that bleed hole on the side but that's just going to help me push this down into place and i've also lubed up these o-rings and we're going to tighten this compression adjuster assembly down to 22.1 foot-pounds all right one more thing with this we got to do the final bleeding so we're just going to pump this rod down a few inches maybe 8 or 10 times and then from here you might want to get a rag i'm going to cover that bleed hole and i'm going to pump this all the way down and any extra oil is going to come out of this hole so we're just going to tip that sideways now one other thing you can do is take that bleeding screw out and you can actually let this hang upside down for a minute make sure it gets all that extra oil out so one final check with this damper cartridge we're going to press this down all the way again and then i'm going to watch it extend all the way out make sure there's no dropouts or spots where this thing is not consistent and again make sure it comes out all the way on its own so if you can pull on this and it comes out just a little bit that means there's air in the system at this point we can install the seals in the same way we did on the other fork so we've got our dust seal then we've got our retaining clip our oil seal and again just make sure the oil seal is in the correct orientation so we have this garter spring with that lip protruding down towards the bottom once you've done that you can you can remove your seal bullet install the backup ring we have the lower bushing make sure you don't scratch that up and then the upper bushing now we can slide on this outer fork tube and again we're going to heat this area up where that lower bushing sits so we'll slide that bushing into place remove the fork from the vise and install that oil seal so we heard that pitch change we can now install that retaining clip and that open end i just put that in first and squeeze it together then again you want to make sure that retaining clip is all the way fully seated in its groove after that we're going to install the dust seal we're just going to put push down on that inner tube and it'll pop it right into place now we can reinstall this fork assembly back into the vise we can install this damper cartridge now this is the same thing as the air chamber we have that hex bolt at the bottom and you need to make sure it's lined up with the bottom of the fork tube then we can install the rebound adjuster bolt and we're going to torque this bolt to 29.5 foot-pounds now we can fill the fork with the same amount of oil we did on the other side so for us it's 220 milliliters now we're going to slide that outer tube up then we'll tighten that fork cap down in the vise you want to refer to your manual for the torque spec on that i need to reinstall this bleeder screw then we can reset our compression and rebound adjusters to the same positions they were before we took this apart once you've done that you can go ahead and wipe any seal grease or any other oil you got on this and now we can reinstall them on the bike we'll start with the left fork and make sure you put that schrader valve where you can reach it now the lower clamps are going to be tightened to 12 newton meters and the upper ones to 17. now for some of you before you tighten this upper triple clamp make sure you tighten this fork cap down now we'll do the same steps on the other side after that we can install the wheel and that is how you replace your fork seals or just change out the fluid on these wp aer forks it's really pretty simple process if you need any of these parts be sure to get them on our website whether it be the seals or the fluid now for more helpful content like this subscribe to our channel thanks for watching [Music] you

Channel: Rocky Mountain ATV MC

Views: 13,633

Rating: 5 out of 5

Keywords: Rocky Mountain ATV/MC, rmatv, rmatvmc, motocross, rockymountainatv, dirt bike, motorcycle, off road, wp forks, wp xact forks, wp xact pro, wp xact pro forks, wp xact air fork, wp xact aer fork, fork seal, fork seals, how to, how to replace fork seals, leaking forks, leaking fork seals motorcycle, leaking fork seals dirt bike, ktm wp fork rebuild, husqvarna fc 450, wp xact aer forks, motorcycle fork seal replacement, fork rebuild, fork seal replacement, wp xact 48 air fork

Id: VzDEBFIX-wQ

Length: 26min 25sec (1585 seconds)

Published: Wed Feb 17 2021