Front main seal

I have a 2013 R1200GS, last of the air/oil cooled models. On a recent road trip oil started leaking from behind the front cover that covers the alternator belt and pulley. I removed the cover and it appears to be leaking from the main crank seal. I talked to couple different dealers to get estimate, and neither could give me an answer since they had never changed one. Has anyone else had this problem? Could something else cause the seal to leak, excess pressure in crankcase from bad oil pressure relief valve, crankcase breather assy? I purchased the bike used with 5K miles on it last year so don't know the storage history or use of it. Looking for ideas, or am I just lucky to have one to the rare front seal problems.

Have a look in the bottom of the air filter box: if crankcase pressure was excessive, or if the oil was just over-filled, there might be some oil in the bottom of the box. Drain it by unscrewing the appropriate plug.

Does the bike have synthetic oil in it? If so, it may be worth a change to dino oil, since there is history that sometimes a synthetic will cause a seal to leak, and "sometimes" reverting to dino stops it after a while. And it's cheaper and easier than tearing into the engine; always try the simple stuff first...

I'm not tuned in to the 1200s, but I haven't heard of any bad pressure-relief valves or breathers on the 1150s or 1200s, but it could happen.

Speaking of pressure-relief - question for the gallery - do the 1200 oil filters have a built-in valve? And if so, might a bad filter be a contributor to this issue?

Pauls1150 said:

Speaking of pressure-relief - question for the gallery - do the 1200 oil filters have a built-in valve? And if so, might a bad filter be a contributor to this issue?

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Yes - the OEM and some aftermarket filters do appear to have a built-in valve.

I'd lean towards a bike that has sat for a long time (since it only had 5k on it) and the seals have dried out from lack of use. I don't remember reading about anyone else having this problem.

From what I can tell from the parts fiche, and the RepROM - the front radial shaft seal is press fit into the housing using Dow Corning sealant 07 58 0 397 777. It appears that you have to lock the engine at TDC, then remove the alternator belt and pulley, which should give you access to the seal (part number 11 11 8 528 387).

Since it has been sitting, older, with low mileage..... I would give it a dose...or a dose plus of this-



I have used enough of the Lucas products and had results good enough, I can recommend them.

https://lucasoil.com/products/engine-oil-additives/engine-oil-stop-leak

Additives in the stop leak allow for the older seals to "limber up" and become what they can be.

Lucas products are available most anywhere auto parts are sold.

OM

Oil pressure - oil pump, filter, presssure relief valve, etc. - should have nothing to do with the seal leak. Excess crankcase air pressure due to faulty crankcase venting might though, but I doubt it. I suspect damaged or tired seal.

PGlaves said:

Oil pressure - oil pump, filter, presssure relief valve, etc. - should have nothing to do with the seal leak. Excess crankcase air pressure due to faulty crankcase venting might though, but I doubt it. I suspect damaged or tired seal.

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Interesting you mention this Paul. I was just at my brothers house to see how he was making out on a stator replacement on his Honda VT1100.
He mentioned he had a valve cover leak and I suggested he remove the "plug" in the end of the "drip" tube as this will allow better PCV flow. I believe its purpose is to keep some of the crankcase boogers from migrating out of containment. Probably works fine when the bike is new but as things age.....
Better crankcase ventilation has been the cure for this type of thing in the past. As for the OP's seal, I think it can be limbered up.
OM

Turned out to be corrosion build up on the crank. Crank cleaned up, new seal installed, problem solved.

Thanks for letting us know how you made out
OM