O series oil leak

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Kilroy
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O series oil leak

Post by Kilroy » Sat Aug 18, 2012 12:20 am

That was going to be '1700 oil leaks' in honour of the number of topics - but I thought it might give the wrong impression.. ;)

So now its 1702...

Anyway - for any who may be interested - there is a tendency for higher mileage O series engines to leak oil from the front oil seal on the crankshaft - which is in fact in the oil pump.
This is possibly one factor that causes it, as there will be pressure behind it.
The other factor - and the one many of my cars suffer - is that the oil seal has actually worn the surface of the crank, so a new seal is only a short-term fix.
I have also found that engine reconditioners fail to dress this surface when the crankshaft is being reground - presumably they do not understand the significance.
In future I will point it out.!

My solution has been two different methods - as I wanted to see which worked best. So far - both.
First was to use two thin seals in place of the wide original. This effectively has the two individual seal lips running either side of the worst worn area.
Second was to fit the original size seal with the front edge of the seal protruding 3-4mm out of the pump - which also moves the position of the seal lip. There is adequate space in front of the seal to allow this.
Because this reduces the amount of the seal pressed into the oil pump housing, I use a silicon retaining agent when fitting the seal.
I also dress the crankshaft surface with fine emery paper while the oil pump is off, but the damage goes deeper than could be fixed by hand - and I'm not about to strip the engine completely for one oil leak - especially as many of them were rebuilt in the not too distant past.

It is easiest to do this with the radiator removed - and how fortunate that the Marina has about the easiest to remove radiator ever.!
I also remove the grille to make access easier, then its just cambelt, water pump pulley and fan, and crankshaft pulleys off before the oil pump itself can be removed.

All done before lunch.
Cheers.

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Number 63
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Re: O series oil leak

Post by Number 63 » Sun Aug 19, 2012 12:02 pm

The seals are more like the 'blown' type that use pressure to psh the seal down onto the shaft. Great if it's good quality hardened material but not if it's relatively soft cast iron..

Good workaround though. :thumbup:
1974 White 1.3 Super Coupe, lots of Alfas....

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