leaky front main seal

[paolomarks]

So my front main seal leaks on my AAZ.  I just rebuilt the entire motor including a new front main seal. 
Why is it leaking?  When  I change it what should I do different. Maybe Don't push the seal quite flush into the carrier to try and line the seal up with a fresh surface on the crank?  RTV?  Thanks, Paolo

[theman53]

Is it leaking around the crankshaft or in between the seal and carrier?

[Rock3tman]

check out "wear sleeves"...I used them successfully on a 1.6TD rebuild with +250K on original German
crank nose and both of the intermediate shaft journals that had pretty deep grooves from the seals,
but otherwise were unworn/perfect.

I don't know if they can be installed in an assembled engine. 

[libbydiesel]

Are you sure it is the crank seal that is leaking?  Any leak from above will run down the front of the block and look like it is the crank seal leaking.  The potential leaks on the front of the block are the valve cover, the cam seal, the sealing surface of the cam cap to head, the intermediate shaft seal, the intermediate shaft seal carrier o-ring and the oil galley plug next to the intermediate seal carrier.  The galley plug is somewhat common on rebuilds especially if the block was tanked and the plug wasn't replaced. 

[bajacalal]

Could be that the shaft is worn or that you have used too long of bolts to reinstall the crank pulley onto the sprocket and in doing so damaged the seal or housing. I've seen this happen.
'

[libbydiesel]

As far as sleeves, go, the part number for the crank/cam/intermediate shaft is 99128.  They can be installed with the shafts in place. 

[bajacalal]

As far as sleeves, go, the part number for the crank/cam/intermediate shaft is 99128.  They can be installed with the shafts in place. 

Good thing to know.

[paolomarks]

Finally got everything sorted out. After a comprehensive check of all the potential leak points, (Thanks, Libbydiesel) it was indeed the front main that was leaking. ( I would add the perimeter of the front main seal carrier as another possible leak point for the front of the engine)
  The leak was between the crank and the seal, not the seal and the carrier.  I ended up swapping the front main seal which was black with one that was orange. The seals were slightly different in that the inner sealing flange was  2mm deeper and thus contacted a fresh surface on the crank. Not sure if the  color of the seal is there to  denote this difference in distance or if a different brand just happened to work out this way, but in any case no more leak!  Paolo