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Fork Seals knackered when coming back from Yamaha!

Started by DaveA, December 18, 2009, 12:41:07 PM

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DaveA

Hi People,

I just wanted some input as to weather yamaha could be to blame or not.  My bike's just gone in for it's MOT, been running fine up until now, but they had to take off the front wheel to replace the valve.   They passed the bike and sent me on my way.   After doing the 2 mile trip home, my front wheel, caliper and fork is covered in fluid from the front fork.   Is this something they could have done/damaged removing the front wheel?  It seems odd that it's been perfect, and from them having it to the two mile trip home, it's knackered.  Not sure how to approach the garage in the morning.....any advice would be aprpeciated.

mz_rider

Dave,

I think you will have to put this one down to bad luck. I can't see how even the most ham-fisted mechanic could damage a fork seal removing the front wheel. To replace the seal you will need special tools – a 27mm hex drive on a long extension and ideally a seal driver. These are easily made. I have a photo on the Yahoo site – I'll post here if necessary. Out of interest why did the shop think the valve needed replacing. Also are you still riding an FJ in Britain in this weather? – I rode to work this morning on my little CBF250 Honda and the roads were like an ice-rink!

Stuart (Glasgow, Scotland)

DaveA

Well, my car king of expired, could put my dipstick in one of the cylinders and get a pretty good reading on how much oil i had.  Faced with a cheap car, ot a cheap bike i picked the latter :) I used my gsxr-750 in all weathers, so figured it was ok.   My dad did have a valid point though, as the forks are always under pressure with the weight of the bike, when they removed the front wheel and went to full extension, something could have just let go.   In theory this sounds possible to me, but not being a mechanic don't know if it translates to practice....either way i thought i had some transport back, and i'm slightly annoyed i now don't :(  The thing that's annoying me the most is i now only have a saturday to get them to repair what's happened, and as virtually every bike place is very busy on a saturday, i think my luck's out.  I don't know if i fancy doing them myself, hopefully they'll give me a bit of a discount for fixing it, as it happened in their care?   My bike came from Wick btw, so somewhere near your neck of the woods :)

I'm bracing myself for a worst case scenario of £100, but....are fork seals interchangable, are they likely to have something in stock that will fit? or am i stuck waiting on ordered parts?

mz_rider

Dave,

The FJ's seals are common to other bikes so your dealer should have them in stock.

I also ride all year round - folk think I'm daft, but it's mostly on smaller bikes in winter. My commute is only 6 miles across town so no big deal.

Wick is a fair way away from me - 300 miles or so north, next stop - the North Pole.

Stuart

racerman_27410

i think it would be worth a look to see if some crud might have got up under the lip of the seal and is allowing fork oil to get out.

easy enough to pop the dust cap and have a look see......also the front forks may be sightly out of alignment (fork tube slightly bent ?)..... does the front end go up and down easily ?... any binding?
brakes make any noise when the wheel is spinning? Does the wheel spin free?

Of course it could have been just bad luck that the seal let go when it did.... dont know until you look under the dust cap on the offending fork.


Kookaloo!

Frank

Pat Conlon

Quote from: DaveA on December 18, 2009, 01:51:52 PM
 My dad did have a valid point though, as the forks are always under pressure with the weight of the bike, when they removed the front wheel and went to full extension, something could have just let go.   In theory this sounds possible to me, but not being a mechanic don't know if it translates to practice....

Yea, this has happened to me. If the dealer lifted the bike under the engine, then your dad's right.  When the forks extended some crud on the stanchion tube(s) below the seals, contaminated the seals.

** That's why I always use a fork stand to lift the front end, to keep the forks under compression.**

Quote from: DaveA on December 18, 2009, 01:51:52 PM
I'm bracing myself for a worst case scenario of £100, but....are fork seals interchangeable, are they likely to have something in stock that will fit? or am i stuck waiting on ordered parts?

As much as a pia it will be, go ahead and wait for Yamaha factory oem fork seals. Aftermarket seals are IMHO, inferior. If you do not want to attempt the seal change, at least take the fork tubes off and take them to your mechanic. It will save you some money.....Again, only use Yamaha oem seals. HTH
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

RichBaker

Quote from: DaveA on December 18, 2009, 12:41:07 PM
Hi People,

I just wanted some input as to weather yamaha could be to blame or not.  My bike's just gone in for it's MOT, been running fine up until now, but they had to take off the front wheel to replace the valve.   They passed the bike and sent me on my way.   After doing the 2 mile trip home, my front wheel, caliper and fork is covered in fluid from the front fork.   Is this something they could have done/damaged removing the front wheel?  It seems odd that it's been perfect, and from them having it to the two mile trip home, it's knackered.  Not sure how to approach the garage in the morning.....any advice would be aprpeciated.

Unless they put a gouge in the tube itself, I don't see how they could damage the seal. A gouge in the tube would pass oil and probably cut the seal.....
Rich Baker - NRA Life, AZCDL, Trail Riders of S. AZ. , AMA Life, BRC, HEAT Dirt Riders, SAMA....
Tennessee Squire
90 FJ1200, 03 WR450F ;8^P

mz_rider

Quote from: Pat Conlon on December 18, 2009, 03:58:40 PM

Yea, this has happened to me. If the dealer lifted the bike under the engine, then your dad's right.  When the forks extended some crud on the stanchion tube(s) below the seals, contaminated the seals.

** That's why I always use a fork stand to lift the front end, to keep the forks under compression.**


Hard to avoid when you get airborne over the bumpies :-)

Stuart

andyoutandabout

The fork seal job is among my least favorites, so do use good seals to avoid unnecessary aggro.
Fair play for riding all winter in the UK. I did that for the years I lived there. Strangely though, I don't miss it one bit.

life without a bike is just life

DaveA

Yeah, it's never nice when you need to pop out, and the seat's covered in ice as it was tonight!  teach me for leaving it out the garage, was only 5:30 at night though!

I went to Yamaha today, and they have said it's the seal gone, and as one's gone they really should do both together.  The price is £130!  I removed the centre stand for the MOT as the spring was a bit weak, and it was hanging down a bit.  If i do decide to remove the forks myself, i have no way of supporting the front of the bike :(  seems like which ever route i take, it will cost the same in tools & stands as it will to get them to do it :/  Guess on this one i'll have to bite the bullet and pay.

andyoutandabout

130 quid sounds about right. I paid around 100 to get the seals done on an Rg250 back in 2000. You'll see in my forthcoming Fj video, what a messy affair the forks are and although easy to make, you need special tools. Even with these and a big workshop I found it a bugger to do.
life without a bike is just life

jvb_ca

Quote from: Pat Conlon on December 18, 2009, 03:58:40 PM
Quote from: DaveA on December 18, 2009, 01:51:52 PM
 My dad did have a valid point though, as the forks are always under pressure with the weight of the bike, when they removed the front wheel and went to full extension, something could have just let go.   In theory this sounds possible to me, but not being a mechanic don't know if it translates to practice....

Yea, this has happened to me. If the dealer lifted the bike under the engine, then your dad's right.  When the forks extended some crud on the stanchion tube(s) below the seals, contaminated the seals.

** That's why I always use a fork stand to lift the front end, to keep the forks under compression.**



Hmmmm...this makes me think maybe this is why my one seal has let go. My front stand supports the front end under the steering head, thus my forks are fully extended every time it is on the stand. I use it when cleaning up the wheels. The seals were all new when I rebuilt my whole front end 2 years ago.(10k km's+/-) I thought I should get longer life out of the seals. I try to keep them as clean as possible wiping off bugs before they dry. But it might be the crud in the fork oil that is causing this. It is time to change fluids anyways.

Cheers...Jake
Cheers...Jake
86FJ1200
Ontario