Oil Leak Rear of Aircooled Engine

[LeeCarey]

Hi All, after a successful camping trip I appear to have an oil leak at the rear of the engine dripping down the center of the inside edge of the fan housing. I'm having trouble locating it but assume its the rear crankshaft oil seal but unable to see it. Assume its not oil cooler as its further forward but he's also covered in oil so is possible. Any tips on identifying if actually the oil seal and is it possible to change with engine in. 

Many Thanks 

[Smiffo]

Is this in reference to the 1984 van in your signature?
What engine is in it? 
 

[LeeCarey]

Hi, 2.0 Aircooled CU

[Smiffo]

Hmmm. 

Out of my depth there - maybe add that to signature and change the title to state air cooled oil leak.
There is a knowledgable chap in here on air cooled vans I think named Sarran1955. Always replies with "cordialement" 

Something air cooled in the title may catch his eye?

 
 

[LeeCarey]

Ok will do, funny enough have been watching his videos and subscribed yesterday to his channel. Very good videos

Cheers

[Rosie n' Jim]

I did both my vans oil seals with the engine in, but would probably be quicker out. Rear tinware and fan housing has to be removed. It's then easy. Worth changing engine mounts, oil cooler O rings and oil filter bracket gasket whilst access is easy. If the seal wasn't at fault, this will fix the other likely causes.

[bigherb]

First thing to check is the oil pressure switch is not leaking.

[LeeCarey]

Will do although that seems a bit further back from where the oil is ending up. Wonder if it's the oil pump gasket.

Rosie n Jim, do you have the procedure to removing the fan housing without dropping the engine. Would like to get in and take a peek but with all these things it's never easy and you sound like a pro

[bigherb]

Will do although that seems a bit further back from where the oil is ending up.

The problem is the cooling air blows the oil from the leak point to where the air exits.

 

[Rosie n' Jim]

Oh crikey, now you ask, it was a few years back now. Mine have tow bars that needed removing. I'm pretty sure I also removed the silencer. I removed the cross member to chassis bolts, allowing the engine to be lowered 3"-4", which gives more space to remove the rear tinware. Then the tinware to engine bay rubber seal. The alternator and piping to the heat exchangers also needs removing. 
This will allow the three rear section of tinware to be removed.  Followed by the fan housing. Then everything is on show and simple to work on.
I'm sorry this is rather jumbled, it's straight off the top of my head.  If you have reasonable mechanical ability and an average tool kit you'll crack it, all be it with much cursing!
I did this when the oil filter bracket gasket let go the evening before a Devon trip. Got most bits off as it was getting dark, then continued at dawn. I was on my way around 7am! But that was the third time I'd done it, second on this van, so all nuts and bolts were clean and free.
But before you go to this effort, give the engine a really good clean with something like Gunk. Being air cooled, the oil will be blown all over the place over time. If you let it idle till warm you may be able to see fresh oil marks appearing.
Good luck.



 

[LeeCarey]

Wow, make it sound so easy. Will spend a few nights sleeping on it

[Rosie n' Jim]

If you're sure it's only the oil seal, I think it can be reached after removing the fan only. I should repeat 'think". Check your Haynes if you have one. The crank hole in the fan housing is quite big, maybe bigger than the seal.