Oil leak frustration

[grandfatherjim]

Earlier this summer I counted seven oil leaks that I fixed. After a 500 mile drive it didn't drip a drop and I even took a picture of the driveway underneath it - dry after sitting overnight!
Well that joy only lasted so long. The oil strainer began leaking, again, so I replaced it. The mechanical fuel pump (no longer in service) began leaking oil out its vent hole, so I replaced it. I forget what else started leaking - several things, including the rear crankshaft seal. I got it stopped again.
Then the other day it started leaking yet again. Cleaned it up, took it for a run, came back - oil coming out the dipstick tube! Gave up for the night but thought about it and realized this had to be excess crankcase pressure..hmm, I wonder if in my exhausted haze I put the pipe from the breather in the wrong place...next morning - yes that's it! I have never done this before but I absentmindedly connected it to the charcoal canister!Dumb dumb dumb but glad to figure it out. Switched it back to normal, went for a run. No more oil out the dipstick! Problem solved!
Wait what's that? Over on the left side - look - lots of oil leaking out!
I'm losing my mind with this thing. OK so I have the rear air housing off, and oil has been leaking from either the oil cooler itself, the oil cooler seals, the pressure switch, or the distributor shaft - can't tell which. I have already recently replaced all but the actual cooler.
Next step, I think I will try a pressure test on the cooler somehow. If I can't figure out a good way I'll swap in another from a spare engine I have but that's always dicey. I'll replace the oil cooler seals even though they are new anyway, and the pressure switch even though it's new anyway.
Hey how about sealant under the distributor hold-down plate? Is oil under pressure right there? I guess it shouldn't even get there so I'll try that too.
The biggest frustration of all this is that we want to go camping on Friday, the engine's all apart, I have no assurance that these things will actually fix my leak, and I'm supposed to be working for a living at the same time.
Anything I haven't thought of?
Jim
72 1700 type 4 dual PDSIT

Here's a picture:

[Hippie]

Aren't these almost supposed to leak--like, back in the day, starting when they were about 6 months old and forever forward except for brief interludes after rebuilds?

Anyway, that pressure sender looks like it's screwed in pretty far to me. Is it a true 10x1mm thread or 1/8" NPT?

[hambone]

There is is rubber ring gasket that fits around the distributor shaft; it commonly leaks. A cheap EZ fix by yanking the distributor.
When tightening down the oil cooler, do it gently and evenly all around. Make sure it's torqued down close to spec, it's not much but I always fake it.
x2 on the pressure sensor.
As for you, Jeepy-boy my bus doesn't leak. Well, much.

[grandfatherjim]

The sender is the type with straight threads, and there's a crush washer underneath it to seal against the block.
Yup, the dizzy O-ring is one of the things I did a month or two back, and the previous one sure enough was brittle and cracked so I figured that was it. And when I replaced it the oil leak did stop, but I had dealt with other issues at the same time.
So, this evening I took a valve from a tire, rubber and all I mean, hooked it to a compressor, and pushed it against one hole of the oil cooler while holding the other hole shut with my thumb. This scientific experiment turned out as I expected - the cooler didn't leak.
It's close to being buttoned back up, so if all goes well I'll be firing it up tomorrow and see how I did. I replaced the sender and the oil cooler O-rings, and put some Permatex between the block and the distributor hold down, as well as on the gasket for the breather.
What a lot of work.
As I'm reinstalling all the stuff I'm wondering if I have lost a ring or two and have had a sudden increase in blowby. I went to check compression but my battery was run down, so I'll do it later. Meanwhile, I leaned on spark plug boot #4 and broke it. Great.

[hambone]

Sounds like you need to take 12 steps away from the bus and take some deep breaths. It's always more sane the next morning.

[Hippie]

...As for you, Jeepy-boy my bus doesn't leak. Well, much.

Yeah, well, I'm not bagging on the leakage...It's not like my Jeep doesn't seep a bit, too...mostly gear lube. Sometimes it smears a greasy streak across the tops of the ricers that I run over.

[grandfatherjim]

All together last night, fired her up and - leaks just as much as before!
Pulled off the hub on the rear of the crank and it does look like the new seal I put in there is leaking...back at it.
Jim

[Amskeptic]

All together last night, fired her up and - leaks just as much as before!
Pulled off the hub on the rear of the crank and it does look like the new seal I put in there is leaking...back at it.
Jim

I invite you to finish this most recent repair (use a thin smear of Permatex Aviation on the crankcase bore as you push in the seal).

Clean the engine with GumOut and paper towels. Dry!
Run for a few minutes and start looking for fresh oil.
If it needs full highway pressure, do a quick run and get under there before the fresh oil starts getting blown around.

Careful cleaning and inspection will help you narrow it down. Don't rule out any of the myriad of gallery plugs.
Colin

[grandfatherjim]

Yes indeed I am suffering from gallery plug anxiety.
It did require a quick highway run but the oil still got ahead of me and was blown around.
I thought I was being clever putting in a double lip seal. The outer (rearmost) lip, at least, appears a little chewed up. I wonder about this as I really cleaned up the hub well, and lubricated it, before installing.
Will report back.
Jim

[Hippie]

That sucks, Jim. Talcum powder, believe it or not, can show up them leaks when you get it cleaned and dried all up.

[hambone]

Are you packing the seal(S) with grease before installation? Grease the hell out of that sucker.

[grandfatherjim]

Installed another crankshaft seal and the leak was greatly reduced, allowing us to get away for the weekend. Our trip was likely 500-600 miles and I put in less than half a litre.
The underside of the big rear air plenum around the crankshaft is still very wet with oil and we smell the drips as they land on the muffler, but at least we can drive it.
Since for quite some time I have been seeing oil dripping down over the fuel pump, and now know that it is not the fuel pump itself, I'm thinking I have excessive blowby causing oil to get out wherever it can find an escape route.
(In 72 only, the pancake engine has an oil bath air filter. The breather is plumbed back into that, and I suspect it's blowing the air filter's oil around too - including out the warm air intake, which is just above the fuel pump.)
Well that's my story. I'll check compression when I get a chance; maybe a set of rings is in my future. Could even help me climb a hill.
I did coat the hub with grease, but I didn't pack the seal.
Jim

[Hippie]

That kind of case pressure would be popping the dipstick off its seat wouldn't it?

[grandfatherjim]

My dipstick is quite a tight fit, and I don't think it has much if any of that string stuff inside the cup anymore.