Author Topic: Crankcase seal leaking  (Read 2990 times)

Offline Rob62

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Re: Crankcase seal leaking
« Reply #30 on: October 28, 2017, 11:00:49 AM »
Nice one blasta... hopefully you have solved your problem without major surgery !!

Offline Moorey

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Re: Crankcase seal leaking
« Reply #31 on: October 28, 2017, 12:11:41 PM »
Good man at least you have tried it. Hopefully all will be good and you can think how much money you have saved yourself.
Nothing ventured.........

Offline Tomb

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Re: Crankcase seal leaking
« Reply #32 on: October 28, 2017, 01:05:36 PM »
Hope it works, good job done if it has.
Tom
'73 CB550 with CB500 engine café racer
'62 CB77 Sprinter
'70 CD175
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And a load of old Yamaha 1100's

Online K2-K6

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Re: Crankcase seal leaking
« Reply #33 on: October 28, 2017, 03:56:32 PM »
Looks alot better than the initial photos so hopefully you'll get a reasonable assessment of it now.

As some of the others have said,  it's really not hard to split the bottom with it upside down if you need to go that route so either way you'll get it sorted.

It's quite often looked at as a major task to remove the engine and carry out further work but I've changed gearbox components on these in about 3 hours from stop to running again. I'd rather do one of these than lay under a car to get a gearbox out for a clutch change,  which is after all a wearable consumer item.

If you needed eventually to go further,  then the output sprocket shaft is the other major one to replace at the same time while it's apart.

Be interesting to see how it gets on now with that new seal in it.

Offline Tomb

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Re: Crankcase seal leaking
« Reply #34 on: October 28, 2017, 06:52:25 PM »
My CB72 engine output shaft seal leaks a little if the bikes been stood for a week, but only when you start it up, not while standing. It has the original 1962 seals in it, I quite like this feature though, it puts a little oil onto the chain until the engine is warm and the seal softens then stops leaking.

Or was that a unique Honda design chain oiling feature?  ;D
Tom
'73 CB550 with CB500 engine café racer
'62 CB77 Sprinter
'70 CD175
'78 CB550 with sidecar
'80 Z50R
And a load of old Yamaha 1100's

Offline Spitfire

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Re: Crankcase seal leaking
« Reply #35 on: October 29, 2017, 10:08:00 AM »
Fingers crossed

Cheers

Dennis
1976 CB750F

1977 CB750F2 In bits

1964 BSA A65R In bits

Offline Blasta

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Re: Crankcase seal leaking
« Reply #36 on: November 18, 2017, 11:17:55 PM »
Well, I got the bike back together and took it for a ride yesterday. I did about 250 km on it and the seal is holding and there's no oil leak. Hopefully it continues that way :)

Offline MarkCR750

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Re: Crankcase seal leaking
« Reply #37 on: November 19, 2017, 08:47:24 PM »
Good news, great when you can get away with a dodge like that 👍
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Offline Moorey

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Re: Crankcase seal leaking
« Reply #38 on: November 20, 2017, 12:19:49 AM »
Report back regularly please. It's still early days yet. :)

Offline kevski

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Re: Crankcase seal leaking
« Reply #39 on: November 20, 2017, 07:00:30 AM »
Not all lip-seals are locked in place, most just press in.... so long as its the correct size and material...

Not all seals have 50 psi of oil pushing on the back of it. The lip is there for a reason.
And the seal in the picture is not a crank seal, I feel a bodge coming on and some damaged crank cases  >:( looks like Fred Flintstone has already been in there.

Just read this topic, correct me if i am wrong, if the OP had 50psi going on in the crankcase this seal would be the least of his worries would it not, unless the seal is part of the lubrication system which i doubt because crank end float would reduce any oil pressure on the seal, i am not saying this is the correct way to replace the seal, just wondering where the 50psi came from.

Offline mike the bike

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Re: Crankcase seal leaking
« Reply #40 on: November 20, 2017, 07:21:44 AM »
The crankcase isn't pressurised, just the oil in the oilways.
Where's that 10mm socket got to?

Offline kevski

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Re: Crankcase seal leaking
« Reply #41 on: November 20, 2017, 07:37:50 AM »
The crankcase isn't pressurised, just the oil in the oilways.
We know the case is not pressurised, and as the seal is static and the crank has end float the seal isn't either, so where did the 50psi come from?

Offline Blasta

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Re: Crankcase seal leaking
« Reply #42 on: November 20, 2017, 08:30:10 AM »
The weather here is perfect for riding at the moment and I can't keep off the bike  :).....so I've put about 700km on it now and it's still ok.
Will report back as I get more kms on it.

Offline Rob62

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Re: Crankcase seal leaking
« Reply #43 on: November 20, 2017, 10:14:01 PM »
It will be ok, so long as you managed to avoid damaging the lip as you pressed the seal over the shaft... which you appear to have done successfully..... if it was gonna leak it would have done by now. Relax, job done  8)....

Hope I haven’t just put a curse on the job  :o

Offline Moorey

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Re: Crankcase seal leaking
« Reply #44 on: November 20, 2017, 11:53:18 PM »
Report back next week when you have done 5k on it. Enjoy.  ;)

 

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