1975 Bus - Dripping Oil

[BellePlaine]

I've got oil drips, more then I'd like to have. We are about to take a 1,600 mile vacation and I'd like to know if these drips are a red flag or just a cause for concern. The leaking hasn't gotten any worse lately, but it wasn't as bad as it was earlier this spring. Of course, I've been driving it more then ever.

The drips are at the mustache bolts, oil drain bolt, on the fan housing, and one at the lowest part of the fins. My engine has been rebuilt once by a local shop and it is strong. I don't know if the galley plugs have been tapped, but that's my deep down concern.









Conversely, note how dry the oil screen cover is!

[Amskeptic]

I've got oil drips,

Dear BP,
Oil drips? Try 130 million gallons.
Clean the engine thoroughly with a toothbrush and a can of GumOut on the aluminum portions. Run the engine and see if you can catch the origination location(s). There is nothing to be learned from just wondering about it all coating the bottom of the engine. If the leak is slow, run the engine down the road and inspect thoroughly for the origination points during your drive. Finding the source is half the battle.
Colin

[satchmo]

In my experience, the most likely offenders for oil leaks that accumulate in the places you describe are:

1) The oil drain plug gasket/washer

2) The oil pressure sender on the top/left/rear of the engine

Check and tighten those up if needed. DO NOT, however, strip the oil drain plug hole.

If the oil drips are not excessive, just go drive and check the oil frequently.

The oil gallery plug that leaks most often is behind the flywheel, and you get drips at the bell housing. It doesn't sound like that is your worry.

Tim

[Amskeptic]

In my experience, the most likely offenders for oil leaks that accumulate in the places you describe are:

1) The oil drain plug gasket/washer

2) The oil pressure sender on the top/left/rear of the engine

Check and tighten those up if needed. DO NOT, however, strip the oil drain plug hole.

If the oil drips are not excessive, just go drive and check the oil frequently.

The oil gallery plug that leaks most often is behind the flywheel, and you get drips at the bell housing. It doesn't sound like that is your worry.

Tim

When oil continually accumulates at left rear corner of crankcase at the relief valve Big Screw, you can also look at the pesky oil filter mount gasket area. Lower 13mm nut is accessible, upper is not. The BobD awaits disassembly for this very thing.
Colin

[BellePlaine]

While it's very difficult to determine exactly where my new leak has sprung, I feel that it is likely coming from the crankshaft seal at the fan end. The back side (more correctly, the "front" side of the lower fan housing is coated in fresh oil and fresh oil drips from the "rear" of the case as well. Also, the leak occurs mostly when the engine is warm and running. After a while of revving the engine in the driveway, I can see some oil splatter on the pavement. I my gut wants to believe that this crankshaft seal has failed.

So I have two questions: Page 50 of Chapter 5 in the Bentley says,

To replace the oil seal at the fan end..., pull the fan hub off of the crankshaft. To do this, use a special plate shown in Fig. 15-9 and the three fan mounting bolts.

How hard is this? I've had the fan off of this engine before but not the hub. Can I use a pulley puller or must I fabricate a "special plate"? And if so, any tips?

Second question; the Bentley goes on to say to apply a thin film of sealing adhesive (to the recess?). I have red RTV sealant. My question is, will that work?

Thanks all!

BPJumpShot

[BellePlaine]

So I have two questions: Page 50 of Chapter 5 in the Bentley says,

To replace the oil seal at the fan end..., pull the fan hub off of the crankshaft. To do this, use a special plate shown in Fig. 15-9 and the three fan mounting bolts.

How hard is this? I've had the fan off of this engine before but not the hub. Can I use a pulley puller or must I fabricate a "special plate"? And if so, any tips?

I now understand that I need a Harmonic Balancer Puller.
http://www.sears.com/shc/s/p_10153_12605_00947626000P

[BellePlaine]

Well, I hate to count my chickens before they hatch, but I'm pretty sure I found the source of my new oil leak. This is what the oil rear main crank seal looked like. It might be tough to tell in the picture but there was definitely oil forming at the bottom lip.





So, I borrowed a harmonic balancer pulley remover and replaced the seal with a new one.



I haven't started the engine to see if it has stopped the leak yet because I wanted to give the red rtv some time to set first. Just a light coating on the outer race. I used silicone spray to lube the inner race. All in all it was a 45 minute job. I'm hopeful this works.

[Amskeptic]

Well, I'm pretty tough to picture.

Indeed. Good job on getting in there and gittinerdun. Let us know if a new seal cured the leak!
Colin

[BellePlaine]

Hey, what do you know? The rear main seal WAS the leaker after all. No more oil slick on my driveway.

[Hippie]

...If the oil drips are not excessive, just go drive and check the oil frequently...

My experience = When an ACVW engine isn't leaking a little, it's out of oil.

[dtrumbo]

...If the oil drips are not excessive, just go drive and check the oil frequently...

My experience = When an ACVW engine isn't leaking a little, it's out of oil.

=D>

Ain't that the truth!

So I have a dumb question. Were you able to replace the seal with the engine in the bus or did you have it out when you did it?

[BellePlaine]

So I have a dumb question. Were you able to replace the seal with the engine in the bus or did you have it out when you did it?

The seal that I replaced was the crankshaft seal behind the fan, so it was really easy to access with the engine in the bus. I removed the rear most piece of tin, loosened the fan bolts, loosened the alternator to remove the belt, removed the fan, used the harmonic balancer puller to remove the fan hub and there sat my offending seal. It was a refreshingly easy job to accomplish.

...If the oil drips are not excessive, just go drive and check the oil frequently...

My experience = When an ACVW engine isn't leaking a little, it's out of oil.

=D>

Ain't that the truth!

Ha! My oil drain bolt is still dripping, but it's minor. Maybe I'll leave it be so I know when I'm out of oil!

[dtrumbo]

It was a refreshingly easy job to accomplish.

Aren't those the best?!?! Thanks for the step-by-step. I'm sure I'll have to do this sooner or later.