HOW TO Change the Fork Seals on a GSX1400
NOTE: This thread is also available to download as a PDF file from the Downloads (General) Section
From reading the manual, many owners think this quite complex and beyond their capabilities but really it’s very straight forward.
In reading through this article, any quantities of oil for oil/air gap referred to are for standard springs. If you have fitted after-market springs like linear or progressive, use the oil/air gap advised with those springs. Note also that if progressive/linear springs have been fitted, then typically the plastic spacers I refer to below will have been removed also.
1. Get bike setup on Paddock Stand and Headstock stand
2. Remove calipers, front wheel and mudguard
3. Loosen off the two top yoke pinch bolts
4. Loosen off the nut on top of each fork (do not remove!)
You now can work on each fork at a time - so repeat these instructions for each fork leg
5. Loosen the pinch bolts on the bottom yoke of the fork you wish to remove and put and old cushion / blanket, bit of foam rubber etc. underneath where the fork will (almost) touch the ground when removed
6. Wiggle and twist the fork stanchion and slide it out of the yokes. You'll find it gets very close to the floor (hence the cushion etc. above to stop scratching it or banging it on the ground)
OK, the fork stanchion is now out of the bike and we can start on disassembly
7. Holding the top of the stanchion, undo the top nut that you loosened at #4 above. Once it is undone lift it straight up gently. You will see attached to the large nut a rod with a small locking nut underneath. Undo this locking nut and unscrew the rod from the large top nut.
8. Gently pull the small rod out of the fork leg and place to one side
9. Now compress the fork stanchion into the fork lower and pull out the spring and other bits attached to it (there will be a large plastic spacer. Note the order of assembly and which way up the spring is as you remove them (there may be a tapered end on the spring which needs to go back the same upon re-assembly)
10. Get a flat bladed screw driver and gently prise out the fork dust seal from the top of the slider.
11. Once removed, inside you will see a large clip on tgop of the fork oil seal. Using some needle pliers, remove that clip
12. Now get a bowl and turn the fork leg upside down and leave for about 5-10 minutes for all the old oil to drain out.
13. Once drained, get the appropriate fork tool for your 14 and insert down the top if the stanchion. You'll find it lock onto the fork inners.
14. Now get a long allen key and from the bottom of the fork slider, locate the allen bolt in the bottom of the slider. Getting a mate to hold the fork tool, undo the allen bolt. Can be tight!
Sometime here is you don't have a fork tool you can get away without it by a sharp trap on the allen key, or by using an air gun to undo the bottom bolt
15. Once the bolt is undone, get a good grip of the stanchion and the slider and pull them violently in opposite directions. After a few pulls the old oil seal will come out and you will have two pieces of fork in your hand. Note which way the old oil seal fits on the fork leg before taking it off and throwing it away.
16. Get some 1600/2000 grade wet and dry and where the fork slider generally moves (the area normally between the top of the slider and where the fork leg bolts up at the bottom yoke) rub over with wet and dry (wet) - this glaze busts the old rubber build up from old seals and will make the new ones last longer.
Dis-assembly complete!
17. Insert the stanchion back into the fork slider, insert the bolt in the bottom of the fork slider and using the fork tool and allen key (as in #14 above) do the allen bolt up.
18. Slide the new fork seal down (check it is the right way up (as noted at #15) and get it to engage on top of the slider.
19. Now - if you have a fork seal tool, now is the time to use it to hammer the seal in. If not, you can make your own insertion tool from some scrap 41mm waste pipe - just make sure it is long enough to extend past the top of the fork. If using this approach, slide the OLD fork seal on top of the new fork seal, then the 41mm pipe and using a rubber mallet hammer down until the (new) fork seal is seated. Then remove the old fork seal (it will easily prise up). That way you don't damage the new fork seal
20. Re-affix the large clip you removed at #11 - there is a slot in the inside top of the slider it inserts into.
21. Refit the dust seal - this can be tapped in with a rubber mallet
22. Now holding the fork leg upright, depress the stanchion inside the slider (it probably already is anyway) and fill the fork leg up with fresh fork oil until the level of the oil is 108mm from the top of the stanchion (you can measure this by getting a plastic straw and marking it appropriately, holding it down inside the fork leg from the top).
NOTE: If using after-market springs, use the recommended “weight†oil and set the oil/air gap as recommended by the supplier. For standard springs, use 5w fork oil and set the oil/air gap to 108mm
23. Now, keeping the fork leg upright, and holding the slider, pump the stanchion up and down a few times - this gets rid of air in the inner fork. You’ll know when its full as the air bubbles will stop. Once you have done this, leave the fork leg upright for about 5 mins or so for the oil to settle and then re-check the oil/air gap is 108mm from the top of the stanchion (with the stanchion compressed into the fork leg). Adjust as necessary.
24. Now the oil is in, pull the stanchion out from the slider, and re-insert the fork spring and plastic spacer
25. Now get hold of the rod (removed at #8). From the end of the rod set the gap to the top of the small locking nut to 11mm. Once set insert the rod into the stanchion and keep hold of the top.
26. Screw the large nut from the top of the fork onto the rod so it just locates on the top of the nut (which we set the gap of at #25). Nip this locking nut up on the rod.
27. Placing a pad on the floor, and keeping the stanchion upright, screw the top nut into the stanchion. The springs will push back a bit, so you need to be firm in doing this. Once the large nut is located, screw it down into the stanchion but don't tighten it up quite yet.
28. Now insert the re-assembled leg into the bottom yoke and wiggling it again, push it upwards through the top yoke, so the top of the fork stanchion is level with the top of the top yoke.
29. Torque up the 2 pinch bolts in the lower yoke
30. Torque up the big nut on top of the fork stanchion.
31. Torque up the pinch bolt in the top yoke.
Assembly of Fork Leg Complete! Now repeat steps 5 through 31 for the other fork leg. Note in total you will use about 1.2L of fork oil for both legs. The oil/air gap is a better way of adjusting fork oil, as it allows for any discrepancies in manufacture of the fork leg itself.
32. Once both legs are done, re-assemble the mudguard, front wheel and calipers - not forgetting to pump your front brake a couple of times once the calipers are refitted - and just double check that all bolts are correctly torqued
That's it - job done! For someone who hasn't done it before, job should take about an hour or so to do.
As I say sounds complicated, but really isn't....and the fork tool if you need it you can make yourself if needs be (note they are different for K2-K4 and K5-K7)
Fork oil:
• 5W Fork oil recommended with standard springs
• 10W Fork oil typically used with aftermarket progressive / linear springs
Oil/Air Gap:
• Standard springs: 108mm
• Hagon progressive: K2-K4: 150mm, K5-K8: 160mm
• Ohlins progessive: K5-K8: 140mm
Wilbers progressive: K2-K4: 150mm, K5-K8: 160mm
Very helpful indeed....Thanks
Thanks Gsxbarmy for a very detail notes. :onya: :onya:
There was also a youtube video uploaded by a Japanese owner may show some process for reference:
https://www.youtube.com/watch?v=3RJJGPJfOGA
however I have no knowledge to verify is it showing the correct / full process... :undecided:
Its incomplete - just looked at the first part where he is taking the stanchions apart and "pulling out" the oil seal - unfortunately he seems to have completely missed the bit where you have to lock the inner chambers and undo the bolt through the bottom of the slider to be able to do that.
Which if you haven't got the proper tool is the hardest part of the whole job!!
Quote from: froudy on Tuesday, 28 February 2017, 03:55 AM
Which if you haven't got the proper tool is the hardest part of the whole job!!
Absolutely!!!!!! :onya:
I am about to attempt my first fork oil/seal change and was chatting with a hydraulics expert who we use through work. I had mentioned the forum etc and the precise measurements for oil level. Barmy suggested using a straw but ol mate said he uses a horse syringe cut to length to draw excess oil out. I thought it was an innovative idea to share
Yep - top idea!!!
While you're in there it's worth checking the bushes for wear. Replacing them on a bike with a few* miles on makes it ride like new again.
* I did mine at 108k, but judging by the difference they were worn enough to change by 50k.
Quote from: Hooli on Thursday, 17 August 2017, 07:51 AM
While you're in there it's worth checking the bushes for wear. Replacing them on a bike with a few* miles on makes it ride like new again.
* I did mine at 108k, but judging by the difference they were worn enough to change by 50k.
OK - I'm about to tick over 105k so will look into that.
What is the 'magic' fork tool?
I think Hoolis' distance will be miles, yours will be 105km wouldn't it?
Yes - A good observation
I suspect they need doing at 100k in km too, the difference I noticed in mine was the shake when cornering etc that I'd noticed since about your mileage went.
The magic tool is a pipe with the end cut to shape to lock the cartridge. I've got a thin tube about 1" diameter & cut four slots in it with a grinder, it works ok but is not posh. You might be able to crack the bolt out with a windy gun or impact driver. Once the cartridge is out you'll see how it locks in & be able to make a decent one.
I've heard of shaved broom handles being stuffed down the side of the cartridge to get the bolts loose too.
Good plan Hooli. They want a fortune for a genuine one.
In the parts manual http://gsx1400owners.org/forum/index.php?action=downloads;sa=downfile&id=1 (page 71)
There is a bush, Guide (Part 8) and a Bush, slide (Part 21)
Is that the bush you were talking about?
Yup, 8 & 21 were both equally worn in mine. You can tell as the bearing material is a totally different colour to the backing. I think it was a black teflon coating & copper behind but not 100% on that. They just slide on & off so nothing more technical than a small screw driver to lift a corner out of their slot needed to swap them. I smeared fork oil behind them & over them to make sure they slide in nicely.
Those four parts cost me about £75 in this country, but well worth it for the difference they made.
You mean 22 (not 21).
Quite certain you can get the All Balls products in your countries as well. You can find a dealer by first searching the distributor list for your country. http://www.allballsracing.com/index.php/dealerlocator (http://www.allballsracing.com/index.php/dealerlocator)
The fork repair kit (includes the bushings)t from All Balls (All Balls 38-6087) can be had for 30€ https://www.biketeile-service.de/Suzuki-GSX-1400-51783/de/fahrgestell/vorderradaufhaengunggabel/gabelreparatursatz/gabelreparatursatzkomplett386087.html (https://www.biketeile-service.de/Suzuki-GSX-1400-51783/de/fahrgestell/vorderradaufhaengunggabel/gabelreparatursatz/gabelreparatursatzkomplett386087.html)
The fork oil seal kit (All Balls 56-150) another 22€ https://www.biketeile-service.de/Suzuki-GSX-1400-51783/de/fahrgestell/vorderradaufhaengunggabel/gabelreparatursatz/gabelreparatursatzkomplett386087.html (https://www.biketeile-service.de/Suzuki-GSX-1400-51783/de/fahrgestell/vorderradaufhaengunggabel/gabelreparatursatz/gabelreparatursatzkomplett386087.html)
Postage to GB 13€, AU and NZ 42€
No I mean 21, 22 is labelled as an O-ring.
I didn't know all-balls did them. Considering I've changed them once in 10 years I don't mind buying genuine as I know they'll last as long again.
You are right Hooli. I had looked at page 70 for K2, 3, and 4. For K5 on page 71 the numbering is different.
I didn't even notice I was looking at K5 forks, it looked the same as my K2s.
Mine is K7 so assuming nothing has changed since K5
Checked here http://www.robinsonsfoundry.co.uk/shop/online-store/suzuki-parts-finder/gsx/gsx1400/k2-k3-k4-k5-k6-k7-2002-2007.htm#!gsx1400frontforksk6k7 (http://www.robinsonsfoundry.co.uk/shop/online-store/suzuki-parts-finder/gsx/gsx1400/k2-k3-k4-k5-k6-k7-2002-2007.htm#!gsx1400frontforksk6k7) The bushings are the same for all years! But at least the spacers are different between K2,3,4 and K6,7. Robinsons is one of several good sources to obtain part-numbers. Their prices are not that good though. Most of the times I get original parts in Germany for a lot less.
Quote from: Buddynq on Saturday, 19 August 2017, 10:38 AM
Mine is K7 so assuming nothing has changed since K5
I'm pretty sure the only time the forks changed was between K4 & K5, like most things on these bikes really.
I don't suppose anyone has a picture of the "fork tool" that's been mentioned here ?
I'm about to pull out the forks in my 2001 1400, and replace everything.
Thanks,
Peter
http://gsx1400owners.org/forum/index.php?topic=378.msg3079#msg3079
This info is here :frustrated:
Thanks mate.
Ended up finding it after all......about to do the fork removal, so will see how it goes.
Peter.
Quote from: rollerfish01 on Tuesday, 28 February 2017, 02:50 AM
Thanks Gsxbarmy for a very detail notes. :onya: :onya:
There was also a youtube video uploaded by a Japanese owner may show some process for reference:
https://www.youtube.com/watch?v=3RJJGPJfOGA
however I have no knowledge to verify is it showing the correct / full process... :undecided:
at 9:10 the dude puts a copper ring in the oil stop, I just saw this after assembling my own front fork and I didn't put it there. I followed this diagram: https://www.motorcyclespareparts.eu/en/suzuki-parts/2002-gsx1400-motorcycles/front-fork-damper and I don't see the ring in there. I have 2 spare rings in my gasket/bushes set I bought of ebay (all balls racing) and since the set is for more motorcycles I thought they where spare. I also didn't see these rings when disassembling the fork.
Didn't you mean 8:50 to 9:10? That would be the copper gasket (#6 in the drawing in your link) for the bolt. Should go there. Maybe it still clings to the lower tubes?
Quote from: Andre on Wednesday, 03 July 2019, 03:33 AM
Didn't you mean 8:50 to 9:10? That would be the copper gasket (#6 in the drawing in your link) for the bolt. Should go there. Maybe it still clings to the lower tubes?
Sorry for the confusion, I mean at 8:10
@DonatelloI looked into the service manual, Robinsons (all models), 2 German 14 forums, and another Japanese YT video (see below) as well as this forum. Neither shows/mentions these mysterious copper rings. I am quite certain I had these rings left over as well.
https://www.youtube.com/watch?v=wRzRWgtz710&t=136s
Quote from: Changa on Tuesday, 15 May 2018, 06:46 PM
I don't suppose anyone has a picture of the "fork tool" that's been mentioned here ?
I'm about to pull out the forks in my 2001 1400, and replace everything.
Thanks,
Peter
I used a cut broom handle shaved to a point..
It worked very well..
I too replaced the Bushes but at the lowly mileage of 32k miles, they looked like new with no discoloration or evidence of wear.
I did fit a progressive spring kit from Hagon if I remember correctly..
http://www.hagon-shocks.co.uk/catalog/partdetail.aspx?partno=400-277-00K
Be aware that in this kit they DO NOT provide enough oil!!
I ended up using Rock Oil 7.5
By the way Thanks originally to Andre this table for fork oil viscosity is a real eye opener..
As Andre once said, "Don't go off what the can says" (or words to that effect)..
https://transmoto.com.au/comparative-oil-weights-table/
Have a read..
Quote from: Changa on Tuesday, 15 May 2018, 06:46 PM
I don't suppose anyone has a picture of the "fork tool" that's been mentioned here ?
I'm about to pull out the forks in my 2001 1400, and replace everything.
Thanks,
Peter
For the earlier K2-4 models, the tool is easy to make, get a piece of 15mm gas pipe, file 4 arches into one end at 90 degrees to each other and you have the tool done. I may have a picture on my PC, which i'll Add later.
Or do like Simon suggests, a tapered or pointed broom handle which you can jam against the side of the cartridge will often work as well.
:frustrated:
Pictures of the fork tools not both earlier and later forks are here have a look.
http://gsx1400owners.org/forum/index.php?topic=378.0
:cheers:
Quote from: seth on Wednesday, 03 July 2019, 06:10 PM
:frustrated:
Pictures of the fork tools not both earlier and later forks are here have a look.
http://gsx1400owners.org/forum/index.php?topic=378.0
:cheers:
@seth Ah yes - you need to page through to page 3 to see those though, I guess many may not get to page 3 after reading the heading. However there is a thread for the K2-4 tool already in its own right, so I've just updated that with some extra pictures.
http://gsx1400owners.org/forum/index.php?topic=2179.0
I'll also add a link to that thread in the Suspension area
:onya:
Top job as ever buddy
@gsxbarmy :clapping: :worshippy: :notworthy: :salute: :hat: :cheers:
My easy way. I took forks to suspension bloke. New Wilbers springs, seals, oil. All done for under $400. He then set to my weight at later visit. Works perfect.
Did this yesterday. Only "issue" I had was the inner tube being stuck to the outer tube after tightening the bolt for the cartridge. The yellow bushing was stuck on the inner tube and I was being too careful not pulling the tubes away from each other. Though I had made something wrong. After cup of tea they came apart.
@gsxbarmy , if you would like to add Wilbers progressive spring air/oil gap on your list in the first post it's 160mm.
Quote from: DTTW on Friday, 12 July 2019, 08:58 PM
if you would like to add Wilbers progressive spring air/oil gap on your list in the first post it's 160mm.
Thanks
@DTTW , have done so :onya:
Anybody know the dimensions of the copper washer on the bolt at the bottom?
Seen mine is leaking out of there .
I stuck a new copper washer on when I changed the seals but it must be the wrong size
I'm trying to remember if they are a Dowty washer or not (with the rubber section inside the copper).
Just plain copper washers - not sure of the dimensions, but they're cheap enough from Suzuki.
:hat:
In that case, were they annealed before use? as they go hard when sat around for yonks in a packet. Just head them cherry red over the cooker & quench under the kitchen tap before use.
Do you not just heat to cherry and let it cool naturally?
I've always quenched, have I been doing it wrong?
Quote from: Hooli on Friday, 27 September 2019, 08:37 AM
I've always quenched, have I been doing it wrong?
Nope you've been doing it spot on Andy
https://m.wikihow.com/Anneal-Copper
I never heated and let it cool before putting it on. Just stuck it on and tightened up :whatever:
Am I suppose to?
@black14 thanks if it's just a plain copper washer the one on it should of been fine I'm assuming.
So it's leaking because I didn't heat and cool before hand or the bolt is knackered? :whatever:
Quote from: Suzuki boi on Friday, 27 September 2019, 04:08 PM
I never heated and let it cool before putting it on. Just stuck it on and tightened up :whatever:
Am I suppose to?
@black14 thanks if it's just a plain copper washer the one on it should of been fine I'm assuming.
So it's leaking because I didn't heat and cool before hand or the bolt is knackered? :whatever:
Could be either, more likely the washer though if the bolt tightened up ok
Copper case hardens as it oxidises. By heating to cherry red & quenching you removed the hardening making it soft again, then when you do the bolt up the copper washer can deform slightly to form a better seal.
[/quote]
For the earlier K2-4 models, the tool is easy to make, get a piece of 15mm gas pipe, file 4 arches into one end at 90 degrees to each other and you have the tool done. I may have a picture on my PC, which i'll Add later.
Or do like Simon suggests, a tapered or pointed broom handle which you can jam against the side of the cartridge will often work as well.
[/quote]
I remember watching a mate use the broom handle trick, it wedged in there and he couldn't get it out. :lol:
Oh was I supposed to remove the Broomstick??
:whistling:
wooden brakes and now wooden forks, we'll have to watch out for splinters & borer next
At least they wooden rust.
Could creosote the forks so no need for powder coating or polishing? :)
Just have to watch out for Greenies, cutting down trees to make wooden forks, that would upset them. Wooden worry me. My bark is tough. They can get rooted and leaf me alone. Ill fight with my limbs and put then in a trunk. After that my energy would be sapped, would branch into another area where i couldnt be ambushed.
Is there a splinter group forming? :)
Quote from: Notty on Sunday, 29 September 2019, 10:52 PM
Is there a splinter group forming? :)
Only by those that go against the grain.
OK, can we please cease this lively wood related banter, this is after all a tech help thread :onya:
Thanks all
Hi
Just a quick question the guide states a 41mm pipe can be used to drive the new seal into place, however the outside diameter of the stanchion is 45mm can anyone confirm the diameter of pipe required please.
The stanchions are 46 mm. The seal driver size I use is 46/47 mm.
Quote from: Andre on Tuesday, 18 February 2020, 09:19 PM
The stanchions are 46 mm. The seal driver size I use is 46/47 mm.
Thank you
Quote from: gsxbarmy on Friday, 12 July 2019, 11:55 PM
Quote from: DTTW on Friday, 12 July 2019, 08:58 PM
if you would like to add Wilbers progressive spring air/oil gap on your list in the first post it's 160mm.
Thanks @DTTW , have done so :onya:
Edited 1st post for Wilbers progressive: K2-K4: 150mm, K5-K8: 160mm
Fork seals again.
Seems like only recently I stripped the front end down ans replaced my leaking fork seals.
Well, need to do it again, the elcheapo All Balls seals have failed. Will fit genuine this time.
At least the oil weeping out is clear...
:furious:
Not good Eric. Heard bad reports on their stuff before. Original or i think theres oem Kawasaki ones same, on here somewhere.
Mick Hone parts fiche shows these for GSX1400 and SV1000s. Will check the kawasaki part number.
OEM part #: 51153-42F00 46x58x10.5mm seal
34.95 each excluding postage.
Correct stuff Mate. Id check bearing place, NOK, SKF, id trust those brands. Expensive for Suzuki brand.
I used All Balls for wheel bearings once, the sprocket carrier failed to the point I had three half balls left in it. That was in about 7k miles so I replaced everything again & will never use their crap again.
Quote from: Hooli on Tuesday, 17 January 2023, 07:05 PM
I used All Balls for wheel bearings once, the sprocket carrier failed to the point I had three half balls left in it. That was in about 7k miles so I replaced everything again & will never use their crap again.
What did you gobwith Hooli? Suzuki genuine or oem like NSK, timken, skf? I've got AB bearings front and rear, not too bad I reckon, but don't nearly as many miles as you.
I can't remember tbh.
I went to my local bearing place & said a decent set of these please. Which is what I should have done the first time really but didn't want the bike in bits for ages.
When I changed out the steering head bearings on my 2008 model a couple of years ago, I was surprised to see that the originals were a mix of Japanese and Chinese bearings. I've had the bike from new so no chance of them being replaced before. ???
Right, so forks dissasembled, thoroughly flushed out, rebuilt and new fork oil, seals and oil level set to factory, including all suspension settings. New wheel bearings (NSK) and all refitted to bike, all ok. Brakes are sharp again and all is good in the world,
Except
I now have an annoying squeak in the forks under compression and rebound. I lubed everything up when rebuilding.
Any ideas?