Author Topic: Help! Fork seal replacements (Read 4354 times)

tomsmith051 · « **on:** 23 January 2016, 01:49:29 pm »

So, I found the guide for fork seal replacement and thought great, I've got a guide, I've Don fork seals before, shouldn't be a problem. Got the bike on a stand, got a fork out and opened it up. THESE FORKS LOOK NOTHING LIKES THE ONES IN THE GUIDE.

I'm stuck, has anyone else seen these and done a seal change on them?

PieEater · « **Reply #1 on:** 23 January 2016, 02:04:10 pm »

Don't know what guide you are following but those look like the correct forks for the bike, I followed the Haynes manual when I serviced mine. What bit are you stuck on?

tomsmith051 · « **Reply #2 on:** 23 January 2016, 04:19:35 pm »

It was one of the ones on here, no worries though, sussed it. Now it's just driving the new seal in that's the bitch

PieEater · « **Reply #3 on:** 23 January 2016, 04:55:52 pm »

Glad your sorted, a mate of mine had some steel pipe that was the right diameter to fit between the tube and stanchion but even then driving the seals home was a PITA. One of my least favourite jobs on the bike.

tomsmith051 · « **Reply #4 on:** 23 January 2016, 05:18:43 pm »

Quote from: PieEater on 23 January 2016, 04:55:52 pm

Glad your sorted, a mate of mine had some steel pipe that was the right diameter to fit between the tube and stanchion but even then driving the seals home was a PITA. One of my least favourite jobs on the bike.

Thanks mate. Out of interest, what does your Haynes manual say about the oil grade to use and the air gap?

PieEater · « **Reply #5 on:** 23 January 2016, 05:32:45 pm »

Quote from: tomsmith051 on 23 January 2016, 05:18:43 pm

Thanks mate. Out of interest, what does your Haynes manual say about the oil grade to use and the air gap?

Mr Haynes says 5w oil and 140mm with the spring removed and the leg fully compressed 440cc per leg 2001-2002 / 435cc 2003+

I bought some heavier duty 10nm linear springs from K-Tech when I did mine and they advised 10w oil.

sadlonelygit · « **Reply #6 on:** 23 January 2016, 06:07:49 pm »

if you have changed your springs for heavier rate, then a lighter oil can be used as you will need less compression, if you have a lighter rate, then keep the 5w.
i had 1kg/mm springs with a 50/50 mix of 5w and 2.5w oil running 140mm gap.
remember to keep 11mm of thread showing btw

tomsmith051 · « **Reply #7 on:** 23 January 2016, 06:11:45 pm »

How did you guys put the oil in? As it says to measure it without the spring in, but you need to so you can put the screw in the bottom of the fork...

PieEater · « **Reply #8 on:** 23 January 2016, 06:22:25 pm »

Quote from: tomsmith051 on 23 January 2016, 06:11:45 pm

How did you guys put the oil in? As it says to measure it without the spring in, but you need to so you can put the screw in the bottom of the fork...

You shouldn't need to put the spring in to tighten the bolt at the bottom of the fork, the bolt holds the cartridge in place not the spring.

PieEater · « **Reply #9 on:** 23 January 2016, 06:23:42 pm »

Quote from: sadlonelygit on 23 January 2016, 06:07:49 pm

if you have changed your springs for heavier rate, then a lighter oil can be used as you will need less compression, if you have a lighter rate, then keep the 5w.
i had 1kg/mm springs with a 50/50 mix of 5w and 2.5w oil running 140mm gap.
remember to keep 11mm of thread showing btw

K-Tech probably advised a heavier oil for me as I am a heavier rider.

tomsmith051 · « **Reply #10 on:** 23 January 2016, 06:24:10 pm »

Well when I pulled the internals out they came out all in one piece

PieEater · « **Reply #11 on:** 23 January 2016, 06:45:02 pm »

Quote from: tomsmith051 on 23 January 2016, 06:24:10 pm

Well when I pulled the internals out they came out all in one piece

From your second picture where you have taken the top off and removed the thin adjuster rod measure the position of the locknut on the damper rod so you can put it back to the same place later then unscrew it, remove the spacer and washer then the spring will come off.

tomsmith051 · « **Reply #12 on:** 23 January 2016, 06:46:04 pm »

Quote from: PieEater on 23 January 2016, 06:45:02 pm

Quote from: tomsmith051 on 23 January 2016, 06:24:10 pm
Well when I pulled the internals out they came out all in one piece

From your second picture where you have taken the top off and removed the thin adjuster rod measure the position of the locknut on the damper rod so you can put it back to the same place later then unscrew it, remove the spacer and washer then the spring will come off.

Thanks, I'll give that a go tomorrow

tomsmith051 · « **Reply #13 on:** 24 January 2016, 10:22:03 am »

So just to confirm, 140mm gap even if I haven't put the full 440ml in?

PieEater · « **Reply #14 on:** 24 January 2016, 10:56:49 am »

You need to pump the fork tube and damper rod quite a few times to make sure the oil gets distributed through the internals properly, this should allow you to pretty much use the specified amount whilst keeping the 140mm gap.

tomsmith051 · « **Reply #15 on:** 24 January 2016, 12:22:08 pm »

Apologies for all th questions.

Any it's for getting the bolt our of the bottom?

First one came out alright, this one is being a proper arse.

I've tried it with all the internals in, then internals taken out and with a metal rod inserted to try and keep it still while undoing it, no joy.

Does the Haynes specify a way?

(I will be buying a Haynes, deffo need one)

PieEater · « **Reply #16 on:** 24 January 2016, 12:42:22 pm »

I had the same problem and ended up taking the problem leg to a mechanic who used an air gun with the appropriate bit on the bolt and it came out straight away. I've done similar in the past with an electric drill on high speed and a spare Allen key that I hacksawed off to make a straight bit for the drill. I think its the initial force of the drill turning that catches the bolt which frees it so there's no point in keeping it spinning.

I know that others have jammed a tapered piece of wood down the tube to stop the internals from moving but this didn't work for me.

I got pretty frustrated with it as I don't like being bested by a chunk of metal but as it took literally seconds for the mechanic to undo he didn't want any money from me and by that point I just wanted to get the job done.

tomsmith051 · « **Reply #17 on:** 24 January 2016, 03:53:06 pm »

Finally done and they're back in. Thanks for your help.

Pie eater, your last post gave me an idea, so i took an old Allen key, cut off the right angle and mounted it in an electric driver, worked a charm!

My other specialist tools for this job included kitchen scales and a piece of bamboo with a paper clip masking taped to the end. Oh and garden wire to hold the dampener rod out to prevent it falling into the fork while I was putting the oil in.

Found this workshop manual thanks to another guy on here named Neo, it's a bit like the Haynes but not.

http://www.carlsalter.com/pdfs/Yamaha_FZS_1000%28N%29_2001_service_manual.pdf

PieEater · « **Reply #18 on:** 24 January 2016, 05:12:42 pm »

Phew job well done, bet you won't be in a hurry to do that again.

tomsmith051 · « **Reply #19 on:** 24 January 2016, 05:49:01 pm »

No I won't. Although I am planning on the r6 shock mod soon and then potentially sticking a r1 front end on the thing at some point

PaulSmith · « **Reply #20 on:** 25 January 2016, 10:59:15 am »

For most jobs you are likely to do at home, the Haynes manual will be more useful. The Service manual has all the information you need (and more) but is not organised in a way that helps you get the job done.

The Male Whale · « **Reply #21 on:** 25 January 2016, 03:28:02 pm »

A decent bike shop would have charged you an hours labour to do that job on loose forks... £50.00.

Makes you wonder if it was worth all the effort....

I do hope you put genuine seals in there or you will get to do them again shortly......

Whale

tomsmith051 · « **Reply #22 on:** 25 January 2016, 04:41:19 pm »

It took a while yeah, but I can do it myself now and it won't take nearly as long next time, so thats a winner for me.

Plus I'm skint

CamSIXFIDDY · « **Reply #23 on:** 22 July 2022, 03:17:23 pm »

Just got a quick question on the damper rod lock nut! Im sure when I measured mine they were different lengths, I'm sure one had 12mm thread sticking out and the other one had 14 out, anybody know what that should be. Or the range that it can be.

teecee90 · « **Reply #24 on:** 26 July 2022, 12:29:02 pm »

If you follow the fork overhaul procedure you will see that it isn't really necessary to measure the exposed thread on the damper rod:

39. Wind the lock nut all the way down the thread initially.
40. Before refitting the top cap wind the rebound adjuster screw out all the way, then back in again by 42 clicks. Eight clicks equates to one full 360 degree rotation of the screw. This ensures that you retain the full range of adjustment on re-assembly.
41. Fit the fork cap and wind it down as far as it will go on the damper rod. Then back-off the lock nut up the damper rod until it tightens/locks against the top cap.