Articles & photos

Back

Buell guide for replacing front fork seals

3-12-2013 - Here is a little guide on how too replace front fork seals on a Buell XB or Buell 1125R or Buell 1125CR or a Tube Frame Buell X1, M2, S1, S2, S3 and older models.

Here is a little guide on how too replace front fork seals on a Buell 

 

First clean the lower ends off the front fork very good, No more dirt or sand, use water/soap and air.

 

 

Next put some isolation tape on the top cap hex , to protect it from the socket leaving marks on it.

 

Clamp the front leg in good use a cloath to protect the leg for scratches and put a fitting socket ( 32 mm ) on the big nut  

 

Use Size 24 mm for the newer Buell models,

Now the caps can be very tight, but a sharp nock will most off the time loosen theme,  ! Do not clamp the front leg at the upper part, then you are jamming the cap threats  !

When the cap is loose, hold the front leg strait (oil will come out otherwise), and unscrew the cap , lower the outer leg to the bottom position.

 

 

Oke Now comes the part where special tools are very handy,  front fork spring tensioner. We made this one ourself we have done many forks on it.

 

Turn the tensioner tool until you have access to the dampening rod jam nut

  

Now is a good time to check the rebound setting , as you are going to remove the dampening needle, so removing the rebound settnigs

 

Using 2 spanners ( 17 mm and 14 mm )  to loosen the locking nut

 

When you loosened the lock nut you can screw off the top cap , completely with the rebound dampening needle.

 

 

 

Release the spring tension from the spring compresion tool. And remove the pre load tube with rubber damper ring ( not on all model front forks ) 

Take the front leg out the spring conpressor tool, and gently poor out the front fork oil, and take out the spring.

 

With the oil out we can start with removing the seals, I like to work in a area off the front leg outside the normal working travel off the seals, 

to prevent  from making scratches in the working travel.

 

With a flat screw driver ( a nylon wedge is better ) give the dust seal a little tap with a hammer to remove it (be careful here)

 

After you remove the dust seal you have access to the oil seal retaining spring

 

Again with a little flat screwdriver you can take this retaining spring out. ( again be careful )

 

I like to put it around the dust seal to prevent scratches , and slide the dust seal to the bottom off the leg.

 

 

Now you can pull out the lower leg ( the newer models front legs ) or you need to use the lower leg like a sledge puller, sliding it in

and out with force to knock out the seal. The older model 41 mm legs can be a pain some times to get the seal out,

and guide bushings can damage quickly. ( also be careful here )

 

The older model lower leg is removed now with oil seal, spacer ring, outer guide bushing and inner guide bushing ( and don’t forget the dust seal )

The guide bushings need to be removed before you can remove the ring and oil seal,

After cleaning the parts, inspect the guide bushings, and legs , check if you can find scratches in the working travel off the oil seal.

( when this is the case you need to clean that surface first with care and the propper materials please send us pictures at info@twinmotorcycles.nl if

you have doubts )

 

Below the newer model front leg , you need a seal puller to carefully pull out the oil seal  

 

Newer model front leg with spacer ring and lower guide bushing,  * small note the upper ( middle ) guide bushing is non replaceable on these front legs , complete replacement with outer tubes are available. If needed send us a e-mail info@twinmotorcycles.nl 

 

Now clean up, take care off scratches on the legs, breaking the rough (scratches) scarfs with a very fine sanding paper or scotch brite pad try to obtain a cross pattern , this  will help if the scratches are not too deep, if you have deep marks… consider replacing the inner slider, or send off for refurbishing ,  I usually give it one try with deep scratch marks, and inform the customer about this.

 

Now how to put the seal in,  depending on your seal model and version, rule of thumb, the side with the sealing lip and spring is the oil pressure / oil holding side   

This in the In side

 

Now you can have seals with a double lip and double springs , it douse not matter that much. But in this case the outside is just a dust weeper

This is the out side.

 

The construction of the newer legs , with the big tapered start on the legs, I prefer to mount the oil seals on the newer models legs

with the lower leg still out to prevent scratches .

 

With the seal in place, you can mount the new dust seal on the leg, don’t forget the oil seal holding spring. Give the oil seal and guide bushing a little coat off oil before you carefully slide the lower leg in.

Put the oil seal retaining spring back in and ensure it seats in the recess.

 

 Now coat the outside off the dust seal with a little oil, and press the dust seal in by hand

 

The procedure for the older model legs is a little different,

Put back the new dust seal, oil seal retaining spring, new oil seal, spacer ring, lower guide bushing , upper guide bushing, 

sliding on the new oil seal please carefully over the recess for the upper guide bushing  

 

With all in place, slide the lower leg in the upper ( outer tube )

Keep the lower leg out so much you will not work in the working travel off the front fork, and use a front fork seal mounting tool ( they are made to fit a specified diameter seal ) and tap the oil seal in position  

 

Mount the oil seal retaining ring in the recess and the dust seal. Now the front leg seals are in, it's time to fill the leg with oil,

Poor roughly 0,4 liter in the leg, and you now first need to bleed the dampener , you see here a little tool to make this easier, give it 10 strokes , you will feel the air in the stroke, continue until the full stroke up and down feel a smooth resistance , mind you oil can spill out the dampening rod if you do this to hard.

 

Now set the oil level, or air chamber as it is usually called ( every big maintenance it is recommended to replace the front fork oil )

 

Using a suction bottle is a great help here. If you are happy with the suspension as it was, go for the factory advised level,  putting more oil in will make the suspension more progressive while braking

Thicker oil will make the complete suspension settings more firm. For a normal road bike it is good to have a smooth working suspension to absorb pot holes, and other bumps in the road, even while you are braking, When you like to make your suspension more firm that will work perfect on a race track, but on the road, you will lose grip very quickly.

Put your marks right ( see factory settings ) and suck the oil out

 

Now put the spring back in, on linear springs there is no up or down,  on progressive wounded springs there is. The advice is to put the tightly wounded spring end at the top.  

For the working off the spring it makes no difference. But the the lover half off the front leg is unsuspended weight , the top half suspended weight ,  and you want the unsuspended weight as low as possible on a Buell.

 

Put the spring preload spacer back in, make sure the nylon seat is in place and the rubber dampening ring ( not all models have this )  

 

Now put the leg back in the spring compressor tool,  pull out your dampening rod tool again, and pull the rod up.

Put the top nylon in place ( on the older models there is also a steel ring to protect the nylon piece for the preload adjustment pins )

 

Prepare the top cap for screwing back on the dampening rod. Screw the rebound adjustment in. Flush with the top points lining up, this will be the completely closed position for the rebound setting.

Doing it like this will make sure you will have the full range of adjustment, and both legs will have the same reference points, we see allot off bikes with adjustment screws at difference heights left to right. It is impossible to enjoy riding on a Buell then and not developed to work like that.  

 

Now screw the lock nut on the dampening rod to the lowest position, and screw on the top cap until you feel the dampening needle is seated

 

Now screw the lock nut back up to the top cap.

 

Take your 2 spanner again, and tighten the lock nut , 

 

Spring compressor tool removed, you can screw back on the top cap to the outer tube. Use a little oil on the O-ring ,

to make sure it comes off easy the next time. Don’t tighten the caps to hard, hand tight will do.

 

Mount the leg back in and check and adjust the suspension settings.

Before you tighten the axle pinch bolts, compress the front fork a few times, to make sure they are set propper.

Tightening the axle is not pulling the front forks together becasue the front fork legs can bind a little  

 

We hope this helps. For questions send mail to info@twinmotorcycles.nl You can always send us your fork legs and we will do the work for you.