Tutorial: DIY Replacing Fork Seals

How to keep your little baby running smoothly.

Tutorial: DIY Replacing Fork Seals

Postby cawalther » Thu Aug 08, 2013 8:06 pm

I pulled all of the info from the old forum, but was written by me then and now, with priceless help from Squirrelman, especially in concern for safety or damage prevention. I changed the order on a few things to make damage prevention more effective for your fairings or for easier and more ideal directions.

Huge Disclaimer: This is strictly a tutorial intended to help and guide motivated persons based on the factory service manual and personal experience and/or expertise. We are not responsible or liable for any damage or injury incurred before, during or after any and all work performed on any and all parts by you or anyone at any time. You assume all risk and are liable for all results / consequences of all actions.

Recommended tools: (will add more / edit later)
- A bucket / catch pan (the one you change your oil with is perfect)
- Basic tool set including Ratchet & Metric sockets (mostly 10, 12, 14)
- Metric allen / hex wrenches
- Main fork cap (size?) socket / 6p wrench
- Shop rags / Industrial paper towels
- 1 scotchbrite pad (see next post)
- Fork seal driver

Parts / purchase list:
- 3 cans of carb / brake parts cleaner or other cleaner of your choice (1-1.5 per fork)
- Fork seals*
- Dust seals*
- Fork oil (do your research - most MFR's have different viscosity even though it's the same weight, etc)
*Fork and Dust seals can be purchased as a kit at a much better price.

If you need help with the PVC pipe fork seal driver, we have some more DIY help here from Sir Real Ed: http://vtr250.org/forums/viewtopic.php?f=27&t=645&p=2565

Fork Oil Level: I went to CVS to get a syringe. Go to the pharmacy and ask. They gave me the 2 tablespoon (20cc?) syringe for free. Then I visited the local auto parts store to get fuel line hose in the lawn tractor section (3 bucks?). This was a bit of a tight fit. i.e. it did not go onto the tip very far but it never moved and worked just fine!

Directions for DIY mostly complete overhaul on your VTR 250 forks start now:

NOTE: Do NOT lift the bike yet.

1. Remove the black caps (fork valve caps) from the top of the forks and let out as much air as possible to prevent spraying oil all over.
2. Remove both upper fairings completely (two allen bolts inside next to tach cluster, possibly 2 screws underneath headlight fairing, be cautious of various clips around headlight and pressure tabs to the tank).
3. Remove the four bolts holding the fender to the fork tubes. Leave the fender but remove the reflectors.
4. Loosen the main fork cap on each fork 1-2 turns. Do NOT remove. These are very tight. The bike acts like a vice in this regard.
5. Loosen the two nuts on the bottom of the right fork tube (14mm?)
6. Loosen the axle (14mm?)

7. Now raise the front end of the bike with jack or other means (a block of wood is nice for the aluminum oil pan). Make sure it is stable and isn't going to fall. I like to be a little rough and rock it side to side and see if it stays. otherwise I tie it off to something.

8. Remove two bolts on bottom of right fork. drop the metal piece from the two studs (NOTE: the direction of this piece does matter but should be stamped with arrow).
9. Remove axle
10. Move front wheel assembly out of the way. All you have to do is turn the front end to one side and sort of spin the wheel until you clear the fender and lean it up against the bike. Don't pull too hard since you're still connected with the brake line and speedometer cable.
11. Remove the circlips / pins on top of the fork caps. NOTE: these will prevent removal of fork tube if not removed.
12. Loosen the pincher bolts on the clip-ons and push out of the way.
13. Loosen the four pincher bolts on the triples that are holding the forks in place. You could just do one side at a time so you don't leak any oil. Remove each fork and complete steps for each fork starting at #14 below.

Now you're working on the internals.
14. Completely unscrew the fork cap holding the fork upright. Keep an okay to firm grasp on the cap. I didn't have any "SHOOT ACROSS THE ROOM" experience with my forks. I doubt you will either.
15. Remove the "washer", small tube, and spring. The spring is long and will be very drippy! A bucket works well for that.
16. turn the fork over and dump the oil. You can pump the fork tube while upside down to get more oil to come out. You can use the drain bolt at the bottom of the fork leg but it can be quite messy.
17. Now you'll need to take the bolt out of the bottom of the fork leg. So turn the fork over. If it doesn't brake loose. then reassemble the entire fork. Don't screw the cap in all the way. THEN, turn the fork over and push down on it. Then undo the bolt.
18. Remove the stop ring inside the fork leg by the seal. This can be tricky. I like to use two small screwdrivers. Give it resistance at one end and slide the other one around pulling it out little by little.

Step 19-20 are illustrated in the picture below.
19. Holding the tube (chrome) in one hand and the slider (black) in the other, push the fork tube in about halfway and pull them apart VERY QUICKLY! It may take 2 or 3 times and they'll come apart. So don't lose grip and damage the tube.
20. Here's where you get all your pieces. So don't lose track of what goes where. The oil lock piece didn't come loose on my first fork but did on the second. not a big deal if it stays in the tube. except that oil stays in the tube around it and can't get out except by turning the fork over and leaving debris in the tube. It is ideal to remove the oil lock piece. Spray the tube with your finger over the bolt hole in the bottom and then cover the other end with your hand and shake it good and then dump. I did this about two or three times just to make sure it was clean. I did the same with other pieces or at least wiped them clean with shop towels.

Fork setup.jpg


21. Now that you have the tube out you'll notice the piston, piston ring, and a spring inside the tube. Clean these up nice as well.
NOTE: Since you don't really have the tools for checking stuff, don't stress measuring the spring length and this that and other. But I did look at the bushing and back-up ring. Those did seem to actually be important to me as they show in the manual what to look for if they're worn too far.

22. Now that you have a clean system you can pretty much work in reverse. here's a quick rundown of that:

- Fork tube: install piston, ring, and spring
- Place the stop ring and oil lock piece onto the piston
- Slider bushing
- Back-up ring (put the "rounded" side down. kind of hard to tell, look at reflection to light)

The manual has you put the bolt in last into the piston to hold the fork tube in. But I wouldn't want the stop ring and oil lock to fall off. I think I went ahead and tightened that all up. And if you use PVC you can put the cap back on the tube so you don't get PVC babies/turds into the fork. If you do get junk in there you'll have to clean it all out again or you risk damaging the innards.

23. Slide the fork tube down into the slider and into place.

24. Now slide your new fork seal on the tube and slide it down a bit, more towards the fork slider. Oil up the outer diameter all the way around and then oil the lip of the fork slider (black fork leg) so it will install easier. Helpful tip: try using one of the old oil seals on top of the new seal when driving the seal into place. This helps prevent any damage to the new seal (especially with PVC driver) when you install. You might try to start the process by hand, pressing down the seal slowly, working your way around equally all the way around until it is hesitant to move anymore. Then drive the seal in.

25. Now you can put in the oil. So push down the tube all the way and for the first time you can pretty much fill up the tube all the way. Then pump the tube in/out slowly about 5 times. Then push the tube down again and fill it up til you're about 4.5 to 5 inches deep. The measurement is 4.88"

Use whatever device you've made or bought and take out the same amount of oil in each fork. My fork oil level is described in the beginning of this thread.

26. Install the spring, washer, and spacer
27. Install the cap and viola. you've changed your fork seals.

the first one will seem like forever. the second one will be so easy!

cheers!
Walth
89 VTR 250 (since '07)
06 DR650se (since April '15)
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Re: Tutorial: DIY Replacing Fork Seals

Postby cawalther » Thu Aug 08, 2013 8:49 pm

Untouched posts from S-man (except for line spacing & added bullets)

squirrelmanxx: 12/19/09
- Loosen about 1 turn but don't remove the fork caps while they're still mounted on your bike.
- Wash out fork internals thoroughly with the solvent of your choice.
- Use old seal on top on new seal for protection when pressing back in.
- Scrub the area where seal goes with solvent and green Scotchbrite to clean out any debris, and lube the seals and seating area with fork oil before installation.
- Forks will slide in easier if you use Scotchbrite to clean fork tubes and upper and lower holes in triple clamps.
- Extreme care is needed NOT to crossthread fork caps, so back out immediately if you see they're cocked or feel undue resistance.


squirrelmanxx 12/19/09
- Right, no vices, LOL !
- Also loosen the larger bolts--front axle, lower triple clamp pinch bolts ( but not the upper) etc. while bike is still down on the sidestand.
- The new fork seals are not properly seated unless the snap ring goes in easily, and they're easily damaged, so use pressure on OUTER DIAMETER ONLY when installing.
- I like to pour a very small amount of fork oil in the area above the seal and below the dust seal for better lube of seal and longer life.
- Also, if you want seals to last, go over the fork tubes with Scotchbrite to remove any debris, and ALWAYS keep the forks clean of any bugs or dried mud, etc cuz anything on forks can damage seals.


Untouched post from Slimshady:
08/28/09
Fork oil weight controls damping, how fast the fork moves in and out in response to road bumps. Just like the pneumatic closer on a screen door, the shock slows down the normal spring action. The closer uses air, the fork uses oil. The closer adjusts the speed by varying the opening the air has to be pushed through, usually with a small screw on the end. Adjustable forks do the same thing, the screws or knobs adjust the opening size to vary the oil flow speed.

Since our forks are non-adjustable damping rod types, the only easy way to change the damping speed is to change the oil weight. The thinner oil flows through the holes much quicker than the thicker oil, speeding up the action. The thicker oil slows it down as it takes longer to squeeze it through the holes. ATF is the factory recommended fill, but ATF does not have a viscosity spec. IIRC, actual testing has revealed between SAE 5 and 25 viscosity among various brands and types. Even different batches of the same stuff can vary.

There is an upgrade, Cartridge Emulators. The emulators sit between the springs and the damping rod and control compression damping. By adding or removing shims from the valve stack you control the speed the forks compress. Rebound damping is still controlled by oil weight, but they give a much better ride. Luckily we use standard 35mm Showa forks (as did some more popular bikes) so they are available for our bikes.

Spring stiffness should be dependent on the rider's weight, heavier needs stiffer springs. Progressive springs are an upgrade over stock, but still a compromise as you have one part # for all weight riders. The cartridge emulator website has a spring rate calculator, you plug in the riders weight and it tells you the spring rate required.


03/14/11
I would recommend using fork oil instead of ATF. When the VTR was built there were essentially 3-4 types of ATF, now there are dozens. Also, ATF does not have a viscosity specification, it can vary from 5 weight on up past 30 weight. Even different batches of the same brand/type can vary. Pouring it in is like using a blindfolded darts game to select your oil weight. The weight of the oil sets the rate of damping, how slowly or quickly the forks move up and down. The thicker the oil, the slower the movement. Generally, the heavier the rider the thicker you want your oil.
Walth
89 VTR 250 (since '07)
06 DR650se (since April '15)
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Re: Tutorial: DIY Replacing Fork Seals

Postby MarkinNam » Mon Apr 27, 2015 8:20 am

Thanks guys, just what i was looking for, is there a quick way to just change the oil?
Romans 8;28 And we know in all things God works for the good of those who love Him, who have been called according to His purpose....Everyone's mind is a different world
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Re: Tutorial: DIY Replacing Fork Seals

Postby cawalther » Mon Apr 27, 2015 8:27 am

There is a drain screw on the side but I'm not sure how much of the oil you'll get out with it. If you drain using that screw, measure how much you get out and put back that amount. And only take off one top cap at a time. I would probably still lift the front off the ground or most of the weight anyway.
Walth
89 VTR 250 (since '07)
06 DR650se (since April '15)
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Re: Tutorial: DIY Replacing Fork Seals

Postby MarkinNam » Tue Apr 28, 2015 3:53 am

thanks Walth,looked at a couple of videos and from what i saw the stuff coming out means all the seals should propabley be replaced, do you know if the VTR and the VT foriks from 88 are any different. the other opt is to buy online
Romans 8;28 And we know in all things God works for the good of those who love Him, who have been called according to His purpose....Everyone's mind is a different world
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Re: Tutorial: DIY Replacing Fork Seals

Postby cawalther » Tue Apr 28, 2015 5:35 am

VT as in.. VT 250 F? I don't know much about them. But you could use 88-89 VTRs. Do your seals leak when riding? Or if you bounce the front a few times, are the tubes wet? Replacing them isn't that hard, the biggest thing is just making sure you lube the top of the tube and the seal really well when you go to install it or it won't want to go in at all. Plus, all the steps above ;)
Walth
89 VTR 250 (since '07)
06 DR650se (since April '15)
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Re: Tutorial: DIY Replacing Fork Seals

Postby MarkinNam » Tue Apr 28, 2015 8:50 am

never had any leaks, good indication to leave well enough alone, from what I see there is 1 oil seal 1 dust seal and it looks like 1 O ring under the fork cap, if I go to trans seals (retailer) they should be able to match for me . Got some wet weather late this week so it may be a good time. take some pics this time and post them, Cheers, Mark Ill also post seal numbers and sizes
Last edited by MarkinNam on Wed Apr 29, 2015 3:57 am, edited 1 time in total.
Romans 8;28 And we know in all things God works for the good of those who love Him, who have been called according to His purpose....Everyone's mind is a different world
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Re: Tutorial: DIY Replacing Fork Seals

Postby MarkinNam » Tue Apr 28, 2015 9:02 am

just to add, mine is an MC15 and I'm starting to think there is very little difference except engine internals like 128 links on the cam chains between VTR and VT
Romans 8;28 And we know in all things God works for the good of those who love Him, who have been called according to His purpose....Everyone's mind is a different world
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Re: Tutorial: DIY Replacing Fork Seals

Postby MarkinNam » Sun May 03, 2015 12:23 am

vt shocks 001.jpg
the seal may come unevenly, just tap it back in on the high sides or apply light pressure in those areas so that it clears and pops out
just about done, I got sick of bike shops asking exhorbitant prices so I went to some bearing/ seal suppliers, most said they couldn't help???? the seals are ID 35mm - OD 48mm and 11mm to 13mm thick I bought mine for $4:00 each the dust boots are more difficult to locate locally so I'll just touch them up with some silicone sealant. To get the seals out I drained the oil, washed the shocks out with mineral turps, reasssembled them and used compressed air to push the seal out,,,,,USE EXTREME CAUTION dont HAVE ANY BODY PARTS WHERE THEY MAY GET DAMAGED, see pics. wrap the ends and use a hammer and cloth to tap gently around seal area, I used full pressure BE CAREFUL OF THOSE STANDING AROUND gawking.
vt shocks 003.jpg
vt shocks 005.jpg
When re- assembling insert the piston minus the oil stop and retaining ring, into the tube- once their through fit the ring and oil stop- feed lower part of shock ( black section ) and tighten screw
vt shocks 006.jpg
....Not all shocks are the same, spring lengths and oil levels differ,,, CHECK your manual is correct for your bike////////07/11/17 the seals from supplier started to leak, at least 1 so i thought how can i shorten the proceedure? I undid all the bolts, drained the fluid removed the front wheel and dropped the forks out. Then I pressurised the forks with air till the seals popped up. reversed the proccedure and bingo, done just refill the fluidand replace caps
Last edited by MarkinNam on Mon Nov 07, 2016 4:16 am, edited 1 time in total.
Romans 8;28 And we know in all things God works for the good of those who love Him, who have been called according to His purpose....Everyone's mind is a different world
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Posts: 94
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Re: Tutorial: DIY Replacing Fork Seals

Postby cawalther » Sun May 03, 2015 7:25 am

8 bucks is a lot better than what you would have paid! nice work. So, step 19 didn't work for getting them apart? Pushing the tube into the fork and then pulling it out as quickly as possible?
Walth
89 VTR 250 (since '07)
06 DR650se (since April '15)
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