Honda CX500 & GL500 Forum

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05-10-2008, 8:53 AM Exothermia Joined on 04-18-2008 Posts 116 Fork seal replacement Well my forks had been low on oil and I noticed after I changed my tires yesterday that they have about run dry. I can hear the springs squeak inside the forks and they are very mushy. So I guess I had better replace the fork seals and fill with fork oil. I just have a couple of questions. I'm planning to get my Dad to help since he's been riding and working on bikes all his life, and I've never done these before, so how much time will this take to get done? Also, I noticed when I had the front axle off that on the front axle holder (the half-moon shaped piece that clamps the axle in place to the fork), the bolts the stick out of the fork for this piece were covered in some kind of oil, as if the fork oil had been leaking out around them. Then immediately after I put my wheels back on I noticed the forks were squeaky and had no oil. Is it normal or possible for oil to leak out via these bolts and if so does that mean my forks are shot or can this be fixed? The forks have no rust and they are otherwise nice looking so I don't want to have to replace them if I don't have to.    Report

05-10-2008, 10:28 AM Abes_CW Joined on 04-17-2007 saskatoon Posts 437 Re: Fork seal replacement 2nd question first, yes fork oil can leak out from the around the bottom bolts.  At the bottom of the fork is an allen bolt, 6mm.  The manual recommends using a locking agent on it, most here don't recommend it.  When I did my seals last year I reinstalled without agent, and one was fine, the other did a very slow drip.  I'd get two or three spots worth overnight.  I redid them again last weekend (one had no leak on the bottom but the seal didn't seat first time, the other seal was fine but was leaking at the bolt), and when I reinstalled I used some anerobic gasket sealant on the threads of the bolt in lieu of a locktite.  A week on and 500km later, no leak, and it shouldn't be too difficult to break free for the next time. I'd say about 2-3 hours for the change.  On mine, the most time was spent on disassembly, not actually changing the seal.  You don't have to remove fairings et al to get to your triple so it should be pretty simple.  Rob Davis' page is excellent for instructions.  Be prepared for difficulty in removing the allen bolts.  An impact driver may be required.  Nothing worse than having it all torn apart and realizing you don't have the right tool to finish the job. Centre stand, jack under the engine to get the front wheel off the ground.  I use a short length of 2x8 lumber between the jack and the engine to evenly distribute the weight.  Remove your brake caliper, and bungee it back so it doesn't hang free.  Remove the speedo cable.  Take off those 1/2 moon thingies.  Mine were marked with punch dots to show which was which, right fork 2 dots, left 1, with dots on both the fork and bracket.  Your wheel should drop out.  My GL I had to deflate my tire to clear the fender. Remove fender. Remove air balancer crossover hose if you have the air suspension (it's at the top of the forks) Loosen the spring cap at the top of the fork.  Don't remove it, just break it free.  The triple will act as a vise to help with this, you want to try to avoid using a vise on the fork tubes when off the bike. (or be carefull, use soft jaws) Loosen the upper and lower pinch bolts on the triple tree on each side.  You may want to note your fork position in the triple, so when you put 'er back together you have the same ride height if desired. The forks should drop out the bottom of the tree. Remove the fork cap, carefully as it is spring loaded and under pressure.  You don't want it hitting you in the eye or have pieces inside fly to the mystery places where they will never be found.  I think it is the same place odd socks go from the dryer.  Press down as you loosen! After the cap is off, you will find a short spring, a spacer (washer type thing), and a long spring.  Note the orientation of the spring coils they will be tighter on one end, for later reinstalation.  Remove these.  They will have gross grey oil on them with a pudding consistency likely!  Wipe them clean.  Pump the fork a few times to get as much gunk out as you can.  I left mine inverted for 1/2 hour to drip out. So far so good. Remove the allen bolt at the bottom.  Don't strip it!  Use the right tool. If you are holding the fork upside down, when the bolt comes out a piston with the rebound spring will fall out.  Note the orientation for reinstallation. Remove the dust cap, carefully prise up with a flat screw driver. There you will find the dreaded circlip/snap ring.  This to me was the biggest PITA.  Again having the right tool makes this short work. With the circlip out,  IIRC there is another bushing to remove.   grab the slider with one hand, the fork lower in the other,  compress then rapidly extend them.  This will pop your old seal out, and the slider will come free for cleaning.  Note the condition of the fork slider bushing, it's a 2" collar at the end.  If it's excessively worn it should also be replaced (copper surface showing over 3/4 of it, it normally has a teflon type surface). With everything clean, it's time to put back together.  Position the new seal, with the numbers facing up, centre it in place.  Guys here bought a 1 1/2 inch pvc pipe fitting to place over the seal to tap on to drive the seal.  I bought one and didn't fit, so I positioned my old seal on top of the bushing on top of the new and used that to drive it down.  Worked great.  You have to get it down far enough so the grove the circlip fits in is exposed. Circlip in, seated in it's groove and your ready to reassemble!  Dust cap on,  Piston with rebound spring in, put some sealant on the allen bolt and reinstall and tighten.  It won't thread in unless you have the fork in an extended position. Drop in the large spring, spacer and top spring.  accurately measure the correct amount of fork oil for your model (listed on Rob's page).  You need the same amount for both forks.  If you spill some out you'll have to empty and start again to ensure they are balanced. Extend the fork, take the top cap, I use a rag between it and my hand, and compress the springs down to tighten the cap in. I put the fork lower between my feet, hold up the slider with my left hand and push down, turn in with my right.  Left hand keeps the fork extended so you don't have to compress the springs far to install the cap, much easier! Your fork is now together, repeat and rinse with the other, and put 'em back on the bike! Don't do them both simultaneously, so you have a complete one as a referrence if you forget where all the bits went. I am not a great mechanic, with you dad helping you it should be a piece of cake.  If I can do it anyone can (of course I had to do it twice....   Rob Davis' link: http://www.elsham.pwp.blueyonder.co.uk/cx500/front_forks_seals/      Report

05-10-2008, 12:18 PM Exothermia Joined on 04-18-2008 Posts 116 Re: Fork seal replacement Yikes! This is going to be complicated. Just what I needed. The more work I do to my bike, the more work I find I need to do. Oh well. Thanks for the info, I'll get the seals ordered and hopefully do them next week or weekend.    Report

05-10-2008, 2:07 PM Abes_CW Joined on 04-17-2007 saskatoon Posts 437 Re: Fork seal replacement It's not that hard, again if I can do it, you can, especially with your mechanic dad on hand.  It's a few steps, but they are all simple.  Just have a plan for that allen bolt if stuck and get a proper snapring tool.  I bought a cheapie and it didn't work well, ended up using one prong of it and a small flat screwdriver.  Otherwise, it's like lego, take it apart, put it back to gether. If your stuck, you know where we are! Darren edit:  You wont believe the difference in the ride when you are done.  It will be worth it, trust me.      Report

05-10-2008, 4:54 PM Exothermia Joined on 04-18-2008 Posts 116 Re: Fork seal replacement Thanks for the encouragement. If it weren't for this forum who knows what condition my CX would be in. I'm just upset now I have to wait till I get it fixed before I can ride again, it's way too mushy for me to ride at the moment.    Report

05-10-2008, 5:41 PM fll1441 Joined on 11-06-2006 Fort Lauderdale, FL Posts 669 Re: Fork seal replacement I also thought it sounded very complicated before I did mine. After doing it, I agree with Abes. It wasn't that difficult. I found a parts diagram from the service manual helpful to make sure I put everything back in the correct order. Take your time and follow the instructions step by step.    Report

05-11-2008, 4:21 AM Shep Joined on 01-30-2007 Hull.East Yorkshire.England Posts 1,896 Re: Fork seal replacement Don't use cheap fork seals though as they are not much good. http://tinyurl.com/45wwhe Fully Guaranteed 'OEM' Quality Natural Rubber seals (Not cheap silicone). These are the type you want. New Global CX/GL Forum, http://globalcxglvtwins.hostingdelivered.com/    Report

05-11-2008, 8:09 AM Exothermia Joined on 04-18-2008 Posts 116 Re: Fork seal replacement What about the Pro-Moly-leakfree-something-or-others from Dennis Kirk? Other people reported them to work better than OEM. Can anybody else verify the best fork seals? I don't want to have to do this again in a year. Here's a link- they definitely aren't cheap. http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=149886&store=Main&catId=416&productId=p149892&leafCatId=41606&mmyId=12260    Report

05-11-2008, 1:27 PM Abes_CW Joined on 04-17-2007 saskatoon Posts 437 Re: Fork seal replacement I just went with Mr Honda's stuff, but the dennis kirk price isn't bad considering you get both the seals and new dust caps/wipers.    Report

05-11-2008, 1:45 PM wridley Joined on 06-28-2007 Didsbury, AB, Canada Posts 131 Re: Fork seal replacement I just finished doing mine this weekend and the cost of seals and dust covers from Honda was $37.00 with no shipping required. Major improvement. Willy 1982 CX500C 1980 CX500D 1981 GL500I (wife)    Report

05-11-2008, 2:22 PM Exothermia Joined on 04-18-2008 Posts 116 Re: Fork seal replacement Today my brother offered an interesting option and I thought I'd ask you wise gentlemen about it. I explained that all the leakage I could see was coming out of the bottom of the forks and not at the top at the fork seals/wipers. He asked why didn't I just remove whatever is in the bottom to allow them to drain, open up the tops and refill them with fluid and make sure I properly seal the bottom this time so it doesn't leak. There is really no leaking going on at the top fork seals so if it would be possible to fix the leak at the bottom and refill them without having to fully disassemble and replace the seals, which aren't leaking, that would make the job much simpler! Is this possible with my forks? They are the earlier, non air forks.    Report

05-11-2008, 4:58 PM PWG in Lowgap NC Joined on 01-08-2008 Minutes from the Blue Ridge Parkway Posts 537 Re: Fork seal replacement I feel not qualified to answer this question as I am neither a gentleman, nor am I wise.  But what the hell.  I see no reason why you shouldn't do it that way.  It is probably just a washer on a drain plug that needs to be replaced.  Good Luck with it. 82 Honda GL 500 SilverWing Trike "Old Yeller" 06 Suzuki S 50 Boulevard Cruiser ANY WARM DAY ABOVE GROUND IS A GOOD ONE (unknown senior citizen)    Report

05-11-2008, 6:04 PM Broncoman2000 Joined on 09-27-2006 Raleigh, NC Posts 132 Re: Fork seal replacement I dont remember anything that could leak from the bottom of the forks on my 79 when I replaced the seals. Mine were obcviously leaking from the seal, as I could watch the oil drip down every bump I hit when it went out. The job is simple, the only hard thing was the damn allen bolt in the bottom. I had to use an impact gun on mine to break it free. I used no loc-tite on mine and have had no leaks. Also, I used a torque wrench when installing it, so no impact wrench next time. 1979 Honda CX500 Custom 42,000 miles and rising, thanks to Dick in Raleigh    Report

05-11-2008, 7:34 PM instructorpilot Joined on 12-15-2007 Orlando FL Posts 204 Re: Fork seal replacement I have a suzuki special tool that holds the dampening rod in place while I undo the screw on the bottom. I had gasket washers on the bottom bolts though. I just replaced them with aluminum crush washers. I have no leaks what so ever. Al 2 CB350F's, 1 CX500, 1 GL500, CB750F, XV500, 2 GL1100's, DL1000    Report

05-11-2008, 7:48 PM Exothermia Joined on 04-18-2008 Posts 116 Re: Fork seal replacement I'm afraid I just don't know enough about forks to ask the right questions here. All I know is this. There is no oil leaking out of the wipers on my forks. When I took my front axle out to change my tire I could see that oil had been leaking profusely from the two bolts that the front axle holder bolts onto, on the bottom of the forks - they were covered in fork oil. I don't know if the other side had been leaking as well. What I would like to know is, can I fix these leaks in the bottom of my forks and refill my forks without tearing my forks apart and replacing the fork seals which aren't leaking.    Report

05-13-2008, 9:47 AM RichNCT Joined on 03-02-2006 Posts 2,139 Re: Fork seal replacement Trying the drain/refill and reseal the bottom allen bolt is worth a try, you might get lucky, the cost and time is small enough to make it worth trying.  However, if you recently purchased the bike, the PO may have had leaking seals until most of the fork oil was gone and then cleaned it up for the sale.  Check for corrosion or pitting on the fork surfaces where the seals travel (not too important up higher, except for aesthetics).  If you have more than VERY MINIMAL pitting in the seal travel area, new seals will leak in a short while too. Born to be relatively wild    Report

05-13-2008, 3:40 PM Exothermia Joined on 04-18-2008 Posts 116 Re: Fork seal replacement There isn't any corrosion on the fork tubes and it doesn't look like there were leaks up there. The weather's been pretty sucky but hopefully by this weekend I'll give it a shot and if it doesn't work, and the fork seals leak, I'll just have to order some and do the whole job. We'll see.    Report

05-15-2008, 6:46 PM Randall-in-Mpls Joined on 07-06-2007 Minneapolis, MN Posts 1,089 Re: Fork seal replacement  Exothermia wrote: I could see that oil had been leaking profusely from the two bolts that the front axle holder bolts onto, on the bottom of the forks It's not those bolts that are leaking.  It's the Allen bolt.  There is (or should be) a copper crush washer on each Allen bolt that needs to be annealed or replaced before reassembly.  You probably had a PO who falied to do that. Regarding a drain and fill only: remove the caps and compress the shocks so you can draw out the lower main springs.  If the ends are full of sludge, I'd strip them down and clean them out (replacing the seals as a matter of course.)  If the oil on the springs looks clean, go ahead and just refill them.  Drain them first, since you need to correct the leaking Allen bolts, anyway. Also, there may be enough tension in the springs with the caps on to prevent the piston turning while you loosen and re-torque the Allen bolt.  And if your '80 uses the same 33mm forks as my '78, you'll need a longer than typical Allen socket to reach the left one. R '78 CX500 - The Black Maggot My mid-life crisis has two wheels.    Report

05-15-2008, 6:49 PM Doward Joined on 05-11-2008 Alachua, FL Posts 61 Re: Fork seal replacement I certainly don't want to hijack this thread, but are the seals for a '78 CX500 standard going to be 33mm x 46mm x 10.5mm? I'm searching eBay for seals, and this size is used on a lot of vehicles.   Some aren't listed for a specific bike, and are cheaper, and listed as this size. 1978 CX500 motor + 1980 CX500C frame    Report

05-15-2008, 7:02 PM Randall-in-Mpls Joined on 07-06-2007 Minneapolis, MN Posts 1,089 Re: Fork seal replacement The parts fiche lists 33x46x11.  What you found should fit, but I can't comment on the quality.  I used OEM.  They're not that expensive. R '78 CX500 - The Black Maggot My mid-life crisis has two wheels.    Report

05-15-2008, 9:15 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 365 Re: Fork seal replacement Pull the axle out and look up inside. You'll see the allen bolts. Put an allen wrench in there (long end in) , put a closed end wrench on the short side and tighten the bolts. THEY MIGHT JUST BE LOOSE. Try it, it's the cheepest thing you can do and it might just be the problem. Refill the forks and see what happens. If it works, then drain them and do it right. Good luck, IT"S easy. If your going to do something, do it right, don't do it half as@*d. http://globalcxglvtw