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Author Topic: Leaking Fork Seals - 400F  (Read 684 times)

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Offline grumpy56

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Leaking Fork Seals - 400F
« on: January 18, 2024, 03:16:13 PM »
Installed two new Honda fork seals and they are both now leaking worse than they did before. No damage to fork tubes or lower legs  that I can tell. Before I rip it all apart again, tried 2 Seal Mates (both now bent) and could not get them inserted between tube and seal. Any suggestions? Thanks.
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Offline bryanj

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Re: Leaking Fork Seals - 400F
« Reply #1 on: January 18, 2024, 04:50:20 PM »
Got to ask what the #*&% is a seal mate
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Online seanbarney41

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Re: Leaking Fork Seals - 400F
« Reply #2 on: January 18, 2024, 06:14:27 PM »
...seal mate is thin flexible plastic for stabbing down between seal i.d. and fork tube o.d. in an effort to free possible trapped debris that may be causing the leak

show us a picture of your seals from the top.  May be able to confirm that you installed the seals upside down.
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Online newday777

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Re: Leaking Fork Seals - 400F
« Reply #3 on: January 18, 2024, 06:54:41 PM »
Did you install the seals with the numbers up or down?
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Offline bryanj

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Re: Leaking Fork Seals - 400F
« Reply #4 on: January 19, 2024, 12:45:27 AM »
Never heard of seal mate in uk and considering fit of seal to tube would think damage to seal is highly likely
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Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline PeWe

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Re: Leaking Fork Seals - 400F
« Reply #5 on: January 19, 2024, 12:58:04 AM »
Oil seals can look different.
You need to verify the direction of the lips. Aiming towards the oil. Feel with finger.
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Offline Tracksnblades1

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Re: Leaking Fork Seals - 400F
« Reply #6 on: January 19, 2024, 01:14:51 AM »
Quote from: bryanj on January 19, 2024, 12:45:27 AM
Never heard of seal mate in uk and considering fit of seal to tube would think damage to seal is highly likely

They’re popular with the inverted forks with large tubes, especially dirt bikes. After removing the dust seal, you run it around the seal. It removes accumulated dirt in the seal…think of walking the piston seal of an automatic transmission down in the bore of a clutch pack…uses the same principle to right the seal’s lip in addition to remove any dirt trapped in it.

https://sealmate.net/
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Offline Nurse Julie

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Re: Leaking Fork Seals - 400F
« Reply #7 on: January 19, 2024, 05:29:52 AM »
Are they the OEM Honda 400/4 double sprung seals, with oil spring and dust spring? If so, the writing on the seal faces upwards when fitted.
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Offline grumpy56

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Re: Leaking Fork Seals - 400F
« Reply #8 on: January 19, 2024, 07:25:42 AM »
Installed seals have writing on top. However, they appear different than these other Honda seals I have.
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Offline Nurse Julie

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Re: Leaking Fork Seals - 400F
« Reply #9 on: January 19, 2024, 07:39:50 AM »
I don't recognise that part number at all 🤔🤔🤔.
It should be 91255-369-000.
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Offline grumpy56

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Re: Leaking Fork Seals - 400F
« Reply #10 on: January 19, 2024, 07:47:09 AM »
glad I didn't use those I guess....
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Offline M 750K6

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Re: Leaking Fork Seals - 400F
« Reply #11 on: January 19, 2024, 02:39:14 PM »
They're CX500 seals. One number out, I think you need 91254 for a CB400.
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Offline Ozzybud

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Re: Leaking Fork Seals - 400F
« Reply #12 on: January 19, 2024, 05:07:21 PM »
What year bike are you working on?

 xxxxx-413-xxx  the 413 is correct for 78-81 CB400T ,T1 T2

If its  400F You need the Seals for Cb360/CB400 xxxxx-369-xxx as stated above in another post.They must have changed the Diameter Slightly.

Not sure if you have seen this page? some great infor=.
 
http://oldmanhonda.com/MC/HCodes.html

ozzybud
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Offline grumpy56

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Re: Leaking Fork Seals - 400F
« Reply #13 on: January 20, 2024, 07:51:03 AM »
Thank you all. I need to verify what seals I put in there (by P/N). My bike is a 1976 CB400F.
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Offline CycleRanger

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Re: Leaking Fork Seals - 400F
« Reply #14 on: January 20, 2024, 09:28:34 AM »
Quote from: grumpy56 on January 20, 2024, 07:51:03 AM
Thank you all. I need to verify what seals I put in there (by P/N). My bike is a 1976 CB400F.

Check the numbers on the top of the seals. They indicate the size of the seal.
I believe it should be 33x46x11

Also this Honda part number 91255-369-000 had been superseded by this number 91255-413-881.
So those OEM seals you show should be correct.
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Offline grumpy56

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Re: Leaking Fork Seals - 400F
« Reply #15 on: January 20, 2024, 10:32:23 AM »
thank you
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Offline Nurse Julie

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Re: Leaking Fork Seals - 400F
« Reply #16 on: January 20, 2024, 11:13:29 AM »
91255-369-000 are 36x46x10.5 mm.
Sooooo, that means the superseded part of 91255-413-881 being 33x46x11 are a different size by my reckoning, I wonder how that works then 🤔🤔🤔🤔
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Offline bryanj

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Re: Leaking Fork Seals - 400F
« Reply #17 on: January 20, 2024, 11:44:49 AM »
They wont fit the tube, unless the size is quoted wrong
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Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline Nurse Julie

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Re: Leaking Fork Seals - 400F
« Reply #18 on: January 20, 2024, 12:43:43 PM »
Quote from: bryanj on January 20, 2024, 11:44:49 AM
They wont fit the tube, unless the size is quoted wrong
Yes Bryan, that is most likely the reason, size quoted is incorrect. The seals have to have an ID of 33mm as 400/4 forks are 33mm OD.
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