Slight accumulation of oil - what to do?

[flloyd]

I've got some oil on a couple of lines attached to the big, motor mounted alternator. I'm not sure where it is coming from but I'm suspecting the front seal on the alternator itself. There is a large line coming from the bottom of the alternator that is very dirty and oil does accumulate on the smaller line that is also attached to the air compressor.

Has anyone seen this pattern before?

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http://www.qrz.com/gifs/IMG_2207.JPG

http://www.qrz.com/gifs/IMG_2208.JPG

Thanks in advance,

[ajducote]

Fred,

What I have found that helps the most is to clean the affected oil soaked area real good. Get it clean, then check that area closely every time you run the engine. That way you will hopefully see where the leak starts at. This is how I found a weird fuel leak I had. The cleaner things are the easier it is to find a new leak.

[Kenneth Brewer]

Yes. Not on the fittings, but on/from the shaft seal, it looks like, where it enters the housing, and weeps a bit onto the saddle like mounting below, not a serious leak at all in my opinion, at this point. I will check it closely tomorrow and get back to you.

[Jon Wehrenberg]

Fred, you are clearly becoming a POG member when you are worried about minor oil and fuel stains.

The smaller line with the fitting at the compressor looks like some tightening is required. I would say do what Andre suggested and clean it, and then determine if its severity merits anything beyond a bit of tightening and then possible occasional cleaning.

The big line coming from the bottom of the alternator, and the oil stain around the bottom of the alternator is common. That is a drain hose so you can remove that without worring about getting a lot of oil on the ground and apply some pipe thread dope or teflon tape to see if you can stop the leak. it may just be a loose fitting, but on my coach I needed to seal both ends because just tightening did not work.

The oil at your alternator is used for not only lubing it, but for cooling and is critical. That is why you see oil at the alternator. Smaller alternators apparently do not require oil cooling. When you run your bus OTR air your big alternator is what is providing the power to keep the batteries charged while the big 24V AC motors are working to keep you cool.

[dreamchasers]

Has anyone seen this pattern before?



On my 1995 Country Coach I have experienced oil leaks on the alternator very similar to yours. I have replaced the seal (available from Prevost) on the pulley end of the alternator with success. Also, I have remove the fitting on the bottom of the alternator and resealed it with thread sealant, but have not sealed the leak. It is a messy job, but doable.

If you attempt the repair, I would suggest applying a double coating of thread sealant to the fitting. I will attempt to re do the fitting seal this winter.

Good Luck,

Hector

[rfoster]

There are 4 or 6 three eights or seven sixteenths nuts around the perimeter of the pulley on the big alternator that are difficult to see - you have to look hard- but a little torque might be what that puppy needs to stop the minor oil leak on the front of the alternator. I have had to tighten them on both coachs that I have owned to eliminate the seepage.

My Memory of how many and what size the nuts are a result of too many Democrats in office. Very detrimental

[Kevin Erion]

I have been told that if you overtighten the fitting on the oil return hose at the bottom of the alternator you can crack the housing. Just be careful!