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Author Topic: My fork seal replacement went bad, minor leak on both sides.  (Read 1124 times)
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« on: January 12, 2022, 03:35:22 PM »

Hello Gents.

I did a ton or reading and videos on doing my own for seal replacement.
I am sure I did a great job except for one final step.
Before installation, I should have manually compressed the forks assembled to see if the new seals were leaking.

30 miles later, my forks leak very little but they do.
I seram wrapped the stanchions and covered them in oil to protect the seals when placing them.

At mile 20 after seal replacement, I used seal mate in case it would help reset the seal lip; still leaked and there was no dirt as expected.
When replacing the seals, I thoroughly cleaned my parts!

Lastly, today, I plan on sanding down in case my stanchion have minuscule runs that allow oil to seep.
As the pictures show, they stanchions looks great so I do not know if sanding is not only not necessary but possibly damaging.

Should I just redo the seal replacement?

To double check, the fork seals have the writing on the UP side, and the seal spring goes on the DOWN side right?

I have marked my DUCATI MANUAL for seals up, pic of one page is also attached.

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« Reply #1 on: January 12, 2022, 03:55:48 PM »

I've never seen much good come from someone trying to sand their fork stanchions at home. It typically winds up either scratching them or making high/low spots which make the leak worse.

I can't tell the up/down orientation of the seals, but your dust caps with the spring is correct. I'd just go back and rework the job. Maybe flip the up/down orientation to see if it fixes the issue. I know for sure, if they're reversed, they'll leak.

Also, what brand are you using? I've used All Balls brand in the past, and they've held up as well (or better) than OEM.
« Last Edit: January 12, 2022, 04:01:09 PM by rule62 » Logged
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« Reply #2 on: January 12, 2022, 04:22:10 PM »


I was told my a bike mechanic how to hold the sand paper to no make "dents" but agree with you that sanding is a job I can easily mess up and there is no RE-do jajaja

I ordered the seals from ducati, they have a single spring where as the ones used before by the shop on my bike had 2 springs; the 2 springs I believe are from ALL-Balls

I had read " the spring faces down" but in the manual it says "marked surface faces the dust seal" which I am sure depends on the brand/type of seal.

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« Reply #3 on: January 12, 2022, 04:59:40 PM »

If the markings are to face down, then I messed up.

At bottom is a document explaining surface area of the seals in pic form.

the part of the seal with the most AREA goes down, and there the seal driver can make the most contact.

on my BRAKE side, from the pic, it look like I damaged the seal  (see first 2 pics0
on my clutch side, the botton has no markings and the spring is facing down.

I placed it with the spring facing down bc I read that and ASSUMED too much.

The largest area of the seal facing down makes sense so the seal driver can be used.

Clutch side, think on the pic a tear can be seen on the seal!!!

Brake side

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« Last Edit: January 12, 2022, 05:10:46 PM by Qomomoko » Logged
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« Reply #4 on: January 14, 2022, 04:13:01 PM »

Your seals are upside down.

The spring goes towards the oil. Flat side of the seal should be visible.

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« Reply #5 on: January 18, 2022, 07:56:01 AM »

Yeah, they were backwards/upside down. I inspected and re used my 'New" seals from ducati.

I suppose I did not read enough/ understand how seals work.

The writing on the outside. The larger Surface area ( means smaller air gap) goes on the outside.
The main reasoning is, that the smaller surface are ( mean more gap  for oil) to press on on the sealing lips and no writing.

Going by the spring location can be misleading as some (as the all balls shows) has two rings. The all-balls packaging has a picture on the outside.

I edited the ducati shop manual to include notes. It is of 2001 Ducati Monster S4, but with exception of the speed sensor, it works for 2002 ( in case some one want a PDF copy, I can email it)

Thanks again for the forum and help.
More than just saving money, but I believe I do the job ( after a mistake or 2) better or more proper as per the manual, than most shops.

Oil seal, inside part (no writing smaller SA, larger gap) , Duc left, all balls right

Oil seal, outside part ( writing and more SA, smaller gap), Duc left, all balls right

Dust seal inside, duc on right, other on left

Dust seal outside, duc on right, other on left

all balls seal and instructions
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