Fork seal replacement

Rigormortis

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Fellow Bikers, is replacing the fork sealson a 2006 R120RT a D.I.Y job or not? Any special tools etc. needed?

I do all the minor servicing myself i.e. filters, oils, tyers, brakes but a bit apprehensive about the forks.

What do you think? BTW. don't have a workshop manual and haven't needed one so far.
 
Hi Rigormortis.
Yes it's a very DIY job. Get yourself a Haynes manual and it will pay for itself with this job.
 
Yes, easy job. Haynes manual is your friend.
Be aware that the tops of the fork tubes are thin and easy to damage when levering the seals out....
 
Easy job, search for Steptoe's tutorial. No need to drop the legs out of the bike. Look at the old seals to see the direction of the wiper, and take care to install the new ones the same way up, i.e. not upside down.
 
Thank you all for your help. I'm tempted to have a go but would feel alot more comfortable with a Haynes maual at hand but unfortunately there doesn't seem to ba a downloadable version so living in Switzerland my only option is the online version but I don't have internet where my bike is located.

Grrrr

P.s. Also I can't find any tutorials by Steptoe.
 
Here's the text of Steptoe's posting, sorry pictures are gone. This is for 1150 but it is the same procedure.

Fork seal fitting
A straightforward job. Which can be done in as little time as 10 minutes. No cycle parts i.e. tank etc, need be removed

The tools needed .



Start by removing the small plastic cap on the top of the fork leg.



The nut underneth can be corroded, so use a hex socket and not a bi-hex if you can



Hex socket.



Place a 22mm spanner on the flats at the top of the leg , under the top yolk.
And the 14mm socket onto the top nut. And undo the top nut.





With the nut removed, push the fork slider down and out of the top yolk.
The front end will be all sloppy, allowing you to push the bars around and out of the way, and the front wheel can be moved in any direction for conveniance.

Pull the fork slider up and out of the stanchion. Wipe the leg as it's removed, as it will have oil residue on it.





Prise out the dust cover - These can be split and deformed, so look before doing the job and have a new one ready if needed.



Underneth you'll see the seal circlip. Prise free with a small screwdriver.



With a seal puller, or similar instrument, pullout the old seal. This is easiest done with my puller by pushing the fork leg as far forward as you can . Remember, the front wheel can moved to almost any position.







There is a washer under the seal. Pick it out,and clean it - Again, this can be corroded.






New seal - Top



New seal - underneth



Locate the new seal in place with your fingers, you can push it home a fair way to start it off



Then with a correct sized socket ( i use a 1" 3/8ths) you want it to run around the outside of the seal, but be small enough to fit inside the slider lips. Fit an extension bar onto the socket, and tap home the new seal.





Refit the circlip .


Refit the dust seal, just a push fit.



Then with a 3mm allen key, undo the small air bleed bolt on top of the fork stanchion and remove it.



making sure you don't lose or damage the "o" ring on the bolt



Push the stanchion carefully back into the slider -remember the front wheel forks can moved around for the best position



Then pull the stanchion back up, so it's in line with the top yolk, in the same position where it will be when it's in place - Now keep the stanchion in place, and replace the air vleed screw.



Now position the fork stanchion back in place in the top yolk, and refit the nut.



Hold the stanchion with the 22mm spanner and do up the 14mm nut, replace the top yolk plastic cover. Job done.
 
Having done one:

Last year.
Very easy.
In my case, it started leaking in Morocco.
Rode away with a rag tied round the fork slider to stop the oil leaking down onto the brake.

Home and bought a new old stock seal from Spain for the princely sum of £6.00.

Since I had lost a lot (I thought - incorrectly) of lubricating fluid, aka power steering fluid, I wished to drain and refill the slider.

At this point, a Sealey vacuum pump for changing the oil in your car is your friend.

Otherwise follow instructions already given or look it up on You Tube.
Little point in changing both seals. It is usually grit holding out the sealing lip.
Myke
 
I did mine on my 2005RT last year, as has been stated here very easy job, no real need for the Haynes manual if you done similar before. Couple of things to watch out for :

If you remove the forks completely like I did, be careful with the bolts that hold the lower fork legs to the bike, they are loctited in and very tight, it can be difficult to get a "square" fit down onto the Torx heads, so quite easy to round them out if you're not careful. The bolts are M8 Torx 40, probably best to get some new replacements to hand first, just in case, then you can replace them. Mine were chewed up by the time I got them out.

The fork sliders are not retained in the fork bottoms, so slide out easily, allowing you to completely drain all the old oil & clean the insides out. There are some small bleed screws at the top of the stanchions to allow the air to escape when you re-assemble them together.

If you do follow the Haynes manual, I believe the fork oil quantity is incorrect, I think it states 620ml per leg... but I'm sure 450ml is the correct value.

Replace the dust seals as well as the fork seals at the same time, they usually come in the kit together.


Mat
 
I did mine on my 2005RT last year, as has been stated here very easy job, no real need for the Haynes manual if you done similar before. Couple of things to watch out for :

If you remove the forks completely like I did, be careful with the bolts that hold the lower fork legs to the bike, they are loctited in and very tight, it can be difficult to get a "square" fit down onto the Torx heads, so quite easy to round them out if you're not careful. The bolts are M8 Torx 40, probably best to get some new replacements to hand first, just in case, then you can replace them. Mine were chewed up by the time I got them out.

The fork sliders are not retained in the fork bottoms, so slide out easily, allowing you to completely drain all the old oil & clean the insides out. There are some small bleed screws at the top of the stanchions to allow the air to escape when you re-assemble them together.

If you do follow the Haynes manual, I believe the fork oil quantity is incorrect, I think it states 620ml per leg... but I'm sure 450ml is the correct value.

Replace the dust seals as well as the fork seals at the same time, they usually come in the kit together.


Mat

Think you're right about the volume. I've taken the plunge and decided after 65'000mls it deserved new oil so took out the forks and measured how much oil they contained 450ml (or just under) is about right. Also my bolts at the lower fork legs are 6mm Alan key.
 
Not going well. Snapped one of the bolts that hold the lower fork legs and dropped the oil seal before I could note which way round it goes into the tube. Grrrr!!!! does anybody know which way round? There is a raise bit on the circumference at one end and a is slightly tappered bit at the other. The photo in the Haynes manual is inconclusive.
 
Not going well. Snapped one of the bolts that hold the lower fork legs and dropped the oil seal before I could note which way round it goes into the tube. Grrrr!!!! does anybody know which way round? There is a raise bit on the circumference at one end and a is slightly tappered bit at the other. The photo in the Haynes manual is inconclusive.

The fork seal fits with the "open side" facing down into the fork bottom leg, ie the side with the writing on is the side you drive the seal into the leg with from the top.

Those bolts are a pain, I replaced mine with M8 stainless allen head, with plenty of copper slip grease. You'll probably have to drill yours out if it's snapped flush, or hopefully if not you can get hold of the snapped bit with a good set of mole grips and turn it out. Good luck
 
Thank you all for your help. Finally completed the job but not without a few scary moments. The worst being one of the bolts holding the lower leg snapping off. Luckily it was the the head that snapped off so I had about 10cm of bolt sticking out to work with and with a bit of gentle heat and Mole gripps managed to undoo it by another 5mm before it wouldn't budge any further so ended up having to drill it out anyway in the hope that a bolt extractor would do the job but it was useless. Next attempt was to drill it out further in the hope that I could then use an M8 tap. Not easy drilling down the middle of the bolt if the tube gets in the way of the drill but this time I got lucky and managed to remove the remaining bits of the broken bolt with the tap.

Regarding the orientation of the seals. Both ends of the seals have open sides although different in so far as one side has a larger opening than the other so put them in with the large opening down the way. They went in pretty easy, in fact I managed to push them in all the way by hand.

Finally snapped off a screw holding on the mud guard...........more drilling and threading. Bloddy Loctite.
 
When you look into a seal, one side has a spring loaded bracelet round it squeezing the rubber onto the shaft you wish to seal. This side should be to the "pressure" side, I.E. in you case, the side with the oil.
 
When you look into a seal, one side has a spring loaded bracelet round it squeezing the rubber onto the shaft you wish to seal. This side should be to the "pressure" side, I.E. in you case, the side with the oil.

+1 I can't remember my replacement fork seals being any different from the many I've replaced over the years, so as stated above, the "open" side where you can see the spring band faces the inside of the fork, and the closed, or flat side faces out. You can drive the seal home into the fork leg with a specific fork driver tool, large socket or just slide the stanchion through the seal, wrap a whole load of insulation tape round the stanchion above the seal, and then use that to tap home the seal into the lower leg. this trick is particularly useful on USD forks, where you can't slide the stanchion in place through the seal once it's been fitted. If I recall correctly, on my RT the seals were a real easy fit into the for leg, I just cleaned everything up pushed them in and fitted the circlip.
 
Well bought my seals from a BMW dealer and both sides have springs in them only difference is that one side has a slighty larger opening (about 5mm compared to 3mm) plus the smaller side has some numbers on it. I'll take some pisture next time I take them out (roughly 12 years or 65'00mls). :hrh
 
Ah OK, my seals were a pattern part replacement kit from Pyramid Parts, the seals were what I would call "standard" type, with an open & closed side.

Mat
 
Well according to the manual:
The seal has 2 grooves. a shallow groove which faces upward toward the sealing cap. The larger recess faces downward.
 


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