Fork Seal Replacement

[masonv45]

Get a Haynes or Clymer manual. It will have the instructions and pictures too. For the first time, it will take at least 1 day to R&R the fork seals.

The fork seals can be changed with the fork tubes still on the bike - or not. The problem with changing the seals with the fork tubes on the bike is supporting the bike high enough to pull the sliders off. For the first time, I recommend removing the fork tubes.

1. Drain the fork fluid by putting bike on centerstand and:
- Release any air in the forks
- Remove the drain bolt in the bottom of the forks. (here is where a manual would come in handy)
- Oil will get everywhere. Use newspaper to cover the wheel/rotor to assist draining into pan. I used masking tape to hold the newpaper to the wheel/rotor.
- Push down on forks several times to push out any oil.
- Reinstall drain bolts to keep oil from dripping out.

2. Remove the front brake calipers and set them on a support - don't just let them hang by the brake line. Either block off the brake handle or wedge something between the pads to keep the pistons from coming out if the brake handle is depressed.

3. Remove the front wheel and then the brace and fender.
- Remove the allen bolt on the bottom of the fork.
- If it spins, you will need an air wrench to remove the bolt. This allen bolt attaches to the rod inside the tube. This rod can spin if pressure is not exerted on it. The spring inside the fork tube applies pressure to this rod but it may still spin.

4. Remove the fork cap:
- The cap is soft aluminum and can be stripped very easily. Do not use a crescent wrench.
- Use a six sided socket (buy one if you have to)
- All sockets have a tapered lip to them before the hex cuts begin. Grid the lip of the socket down until the hex cuts are level with the lip of the socket
- Again, be sure the bike is securely supported and the tank/instruments are covered with a soft towel.
- Applying strong downward pressure, use even pressure to unscrew the fork cap.
- The cap will be under pressure from the spring in the fork, so be careful upon final removal as it will try to shoot out a little bit

5. Remove the spacer and spring.

6. Repeat for other fork.

7. Remove the Fork Seal circlip from its groove in the fork slider by prying up the dust seal cover and using angled snap ring pliers
- These are commonly in poor condition and can be rusted to the fork slider
- If stuck, use penetrating liquid and wait
- If broken, it can still be removed by judicious use of dental pick and snap ring pliers
- Rotating the slider will allow better access angles to the circlip

* If leaving forks on bike, Skip to Step 9 *

8. Remove forks from bike by loosening upper and lower Triple clamps. Slide tubes out from the bottom. Mark where the fork tube lines up with top of triple clamp.

9. Separate the fork tube and the slider by grasping one in each hand and forcefully pulling apart. It may several pulls

10. Clean parts and replace brass bushing if necessary - it probably is. Also I recommend to purchase new circlips if old ones worn out or bent.

11. Cleaning TRAC unit is recommended but not necessary.

12. Seal driver can be made out of PVC pipe and/or Coupler
- if leaving forks on bike, a custom seal driver will need to be made

13. Clean fork tubes making sure they are smooth as a baby's butt. Crocus cloth can be used to smooth out any pits or protusions. Clean out crud inside the tube to verify everything is clean.

14. Closely inspect the area where the fork seal will be sliding. It must be close to perfect condition

15. If leaving forks on bike, verify dust cover is already on fork tube and slide the circlip and then the new seal up from the bottom

15a. If forks are removed from bike, slide old seal up from bottom and then then slide up the new seal.
- The old seal will serve as a buffer to insure the new seal is not damaged when installed.

16. Install slider and install allen bolt at the bottom of the fork slider to hold it to the fork tube. You probably will not be able to torque to spec now.

17. Install seal using driver. It will take some force to get seal mounted. You can feel when it is solidly mounted. Remove old seal if used as buffer.

18. Install circlip into groove in slider and then dust cover.
- Personally, I pack some grease on top of the circlip to keep water from rusting it. You may see some of the grease on the fork slider the first few times you ride, but it will go away.

19. If forks are off bike, install spring, slider into bike and add appropriate amount of Fork Oil. Align forks with marks made in step 8. Tighten Triple clamps.
- Do not use the Recommended ATF - its viscosity is not regulated and can vary by bottle/mfg.
- 10 weight is recommended for light to medium frame riders
- 15 to 20 weight is recommended for medium to large frame riders

20. Initially install Fork Caps with hand on top of socket if possible. If not, use socket and rachet.
- Careful, these caps are aluminum and with the fork tubes being steel it is easy to cross thread. Use 3-1 oil or WD40 to lube cap threads to keep from seizing.

21. Install is reversal of removal (don't cha love that phrase?) for the rest of the front end. Don't forget to torque the allen bolt at the bottom of the forks. And inspect the brake pads and rotors for errant fork oil.

22. Once everything is installed loosen Triple Clamps slightly and torque the bolts starting from the axle and work your way up.

23. Gear up and take the bike for a test ride. Gradually build up speed paying close attention to the feel of the bike on smooth roads, rough roads, and turns.

24. You are now done and can be confident that everything was done correctly - because you care more about your bike than a dealer will.

Below are some tips and pictures that may help you in your fork rebuild.

http://users.metro2000.net/~cdc/magn...65%20magna.htm

http://v4hondabbs.com/index.php?topic=6338.0

Tip: Have you tried reconditioning your seals first?

Method 1: Raise the dust cap and apply several layers of packing tape around the fork tube just above the fork seal. Pump the forks several times causing the packing tape to go into the seal and remove the crud contaminating it. Carefully remove packing tape/oil and crud.

Method 2. Cut 320 grit wet/dry sandpaper into a 6"" by 6" square. Bevel one end by cutting off the corners - leaving a rough looking crescent shape. Raise the dust cover and wrap sandpaper around fork tube with beveled end down. Super glue the overlapping sandpaper to form a sandpaper tube. Make sure there is just enough clearance to still slide the paper along the tube. Work the sandpaper into the seal and spin the paper 5 or 6 times in the SAME direction. Don't go back and forth. Pull sandpaper up, carefully cut off fork and reinstall the dust cover.

Hope this helps!

[rjamesbrown]

You say that 15 to 20 wt oil is recommended for medium to large frame riders. I am 5' 10", 195 lbs without gear. I assume this puts me in medium to large frame range. Would you go with 15 or 20 wt? Or will I really notice a difference? Thanks for the helpful how-to.

- Rick

[masonv45]

I would recommend 15 wt oil for you. Also measure your springs to make sure they are not out of spec. Spring can affect the ride just as much as oil.

If out of spec, I highly recommend some sort of aftermarket suspension: Progressive, Sonic, Race-Tech to name a few.

[masonv45]

Just an FYI, I've updated the fork seal replacement procedure.

[rjamesbrown]

Is it possible to remove the forks without removing the handlebars?

[masonv45]

Yes, it is possible. It requires that the fork tubes stay on the bike.

The fork seals can be changed with the fork tubes still on the bike - or not. The problem with changing the seals with the fork tubes on the bike is supporting the bike high enough to pull the sliders off. For the first time, I recommend removing the fork tubes.

[rjamesbrown]

Right,

What I meant was the entire fork assembly. You say in your how-to that all you need to do is loosen the triple clamps to take out the forks. In a manual I found, they say you need to take apart the entire handlebar assembly. (This is on a VF500F by the way, and I actually haven't taken delivery of it yet so I am only going by diagrams, so sorry if all these questions seem stupid)

[masonv45]

Sorry, yes you do have to remove the handlebars. Try and tie them out of the way so the Master Cylinders stay level.

[rjamesbrown]

Finally at the point to re-fill the forks. Would you suggest synthetic or petroleum based oil? Are there any significant differences between the brands?

[ZuluNinja]

how much oil per tube?

[Rangerscott]

What weight for a small guy. 140lbs - 5' 6"

[ZuluNinja]

hey guys, been out of here for a while but I've been busy with the viffer. At first I just wanted to restore her; then I crashed her back in February and got bit by the customizeher bug; next thing you know:

- HD pipes, custom welded and brackets, wrapped mids (real PITA but def worth it)
- pig spotter rear views
- rims were stripped, left the lips polished and painted the centers red
- re-upholstered Corbin
- screen was cracked on the crash, but had all the pieces; epoxy & paint
- spark plugs, UNI foam air filter, Mobil 1 synth oil

Right now she's just 2 stickers and a head-fairing alignment form being perfect; performance for a 22 y/o bike don't fail to amaze me, this girl still pulls strong! My only gripe is the known problem, shitty fork, but it doesn't concern me till I hit 120mph, then it gets touchy. This bike gets more attention than the Ninja everywhere I go. I thought that after being done with the restoration I would sell her, but I think I'll keep this beauty for a while. Cheers!!! :sportbikesmile:

with the 636, halfway thru restore


beauties at rest


sunbath


headshot






HD Road king(?) pipes


rearview

[Maliboost]

On my ride home I found that my right tube is leaking. Ive been searching through the posts & someone had mentioned that the "bushing" should be replaced with the seal. I found a breakdown on the internet, but am not sure which "bushing" they are talking about.

Anyone know which one it is??

Here is the breakdown that I found online.

Ronayers.com Fiche Desktop Motorcycle Honda 1998 VFR800FI FRONT FORK

thanks mucho guys
Bob

[squirrelman]

upper bushing is #10

unless your bike has lots of miles, those bushings seldom need replacement.

inspect bushing INNER surface area for an even greyish color, but replace if you see bright spots or coppery-looking color, which indicates either high mileage OR a bent fork tube OR both.

check for pits or rust damage on fork tubes.

BTW :you'll be using fork oil, not motor oil

[Maliboost]

It only has 33K on it. In Jan it worked bitchen, in May it leaks. the only difference is 2 trips to the store. :(

I was hoping to order parts B4 I tore into it, Maybe I will order them anyway & replace if they look suspect.

thanks
Bob

[lostlogic]

Crap, too bad I found this after I ordered 5wt fork oil. I read somewhere else online that ATF is 5wt equiv, so ordered that. Can anyone tell me the real story on ATF weight vs. the 'right' weight for a VFR 750 F with a 150lb rider and often a pillion?

Thanks!

[masonv45]

ATF doesn't have a specific viscosity like fork oil, so there's no telling what "weight" you're going to get. Could be anywhere from 4 to 7 weight. However, ATF does work in a pinch.

Typically, 10 wt is recommended. 20 wt if you are a large rider or carry a pillion all the time.

Some have even mixed 10 wt and 20 wt to get a theoretical 15 wt (not sure this logic is valid).

[Adamant]

Kind of off topic, but can you change out the springs without dropping the fork tubes. I.E. pull the springs out from the top and drop in new ones?

[scario26er]

hey, I just replaced the fork seals on my 83 750 now the forks bottom out but only sometimes and I know I used the right amount of fluid. Now my question is would that be spring or bushing related?

[squirrelman]

hey, I just replaced the fork seals on my 83 750 now the forks bottom out but only sometimes and I know I used the right amount of fluid. Now my question is would that be spring or bushing related?

Pull your springs out and check their free length against specs; if they have sagged, you'll need to replace them.

[scario26er]

Took them out and measured they are within spec so what should I try next? The bike is still rideable and it only happens once and awhile I just want to know why there is so much travel.

[dale-j]

Kind of off topic, but can you change out the springs without dropping the fork tubes. I.E. pull the springs out from the top and drop in new ones?

Yes you can. Either support under the bike with a jack, lift the handlebars with ratchet straps to a hook in the ceiling, or keep it to doing one fork at a time and make sure that the bike cannot roll forward off the centerstand when the front sags a bit.