Welcoming Arándano: a 1975 single cab

[jtauxe]

[SGKent]

test the breather box, breather, and hose.

I found on mine that the oil weep is right at the juncture of the seal and case part lines. I suspect that all the engines that leak love to leak at that spot. Once oil gets in that spot it is hard to get a sealer to plug that area.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[jtauxe]

Are you talking about this breather box? The soap bar sized black box held down with the bale, to the right of the distributor, right?

It's empty, and the lines to the collector box and to the air filters are clear.

Isn't that ventilating the crankcase?

If that is all clear, then where would crankcase pressure be building up that would cause a leak in the bell housing (ostensibly through the main seal)... ?
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[Tcash]

[busdaddy]

Did you happen to take any pics of the front of the case while the flywheel was off?
Since you've done the flywheel seal and gallery plugs maybe there's a crack or flaw in the case that only opens when it's hot?, and likely with access to pressurized oil opposed to case cavity pressure, if it was a breather issue it'd probably be puking it out from all the seals and gaskets equally.
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Rust NEVER sleeps and stock never goes out of style.

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[Tcash]

This is all I could find on Crankcase breathing. It mentions a double lip main seal.
https://newsite.hamheads.com/2016/12/10/type-4-crankcase-breathing-system-tests-analysis/

There was a write up on testing crankcase pressure. But I can't find it.
Hook up a pressure gauge to your dipstick and post the readings.

Next time you have the Flywheel off. Put some Dykem layout ink on the mating surface and bolt it back on and look for any uneven spots on the crankshaft.
Or use some Plastigauge.

[Tcash]

[jtauxe]

[Stuartzickefoose]

Your positive it’s oil and not gear oil? Easy mistake to make...transmission input shaft seal. Just tossing the idea out.

Do you seat the rear main flush or in the case a bit?
_________________
Stuart Zickefoose

2011 Jetta Sportwagen TDi 6 speed manual

206-841-7324
[email protected]

[jtauxe]

[Stuartzickefoose]

You need to pull it, clean behind the flywheel, and reinstall, then pull in 100 miles to see where the oil marks are
_________________
Stuart Zickefoose

2011 Jetta Sportwagen TDi 6 speed manual

206-841-7324
[email protected]

[jtauxe]

[Stuartzickefoose]

[jtauxe]

[Stuartzickefoose]

Keep oil in it and worst case you soak a clutch disc. I say go for it! And when you get back the oil will be plenty dark for diagnosis.
_________________
Stuart Zickefoose

2011 Jetta Sportwagen TDi 6 speed manual

206-841-7324
[email protected]

[jtauxe]

I'm back to the high crankcase pressure theory.

Adrian Audirac (Headflow Masters), who built the new 1800 heads and provided them with new pistons and cylinders, also supported the idea that crankcase pressure could be the cause. He suggested just taking off the breather box entirely, for testing purposes, and running it open (with a piece of foam on it or something to keep stuff from going in). So that is my next test.

I have heard two other suggestions for relieving pressure, if in fact that is the problem. One is to add relief ports to the valve covers. The other is to tap into the cylinder head relief ports.

Has anyone here done either of those approaches?
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[Volswagon]

From what I read a while back, possibly on Raby's old site, venting the valve covers basically draws more oil up there instead of having it drain back to the case. Stuffing a couple of copper scrub pads in the breather tower cut down on oil getting in my filter (single Weber progressive).
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I know the pieces fit, cos I watched them fall away.
Wanna hear God laugh? Just talk about your plans.

'75 Bus https://www.thesamba.com/vw/forum/viewtopic.php?t=697183&highlight=

[jtauxe]

Seems to me that oil in the valve cover space would find its way back to the crankcase through the pushrod tubes... or am I missing something in how this is put together?

At any rate, I'm going to try the valve cover venting trick. I'll post results here.
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[Stuartzickefoose]

The point is to put the vents at the TOP of the valve covers to allow intake manifold suction to create negative pressure in the AIR of the crankcase. By routing a vacuum line from the valve cover into the air filter the air space inside the case is then put under a little bit of constant suction. If there’s not negative pressure, even a brand new seal could get blown out by a few psi of pressure. So, by having a vacuum inside the case, even with OIL PRESSURE (totally different) the seals should not leak because the exiting force is sending the pressure into the intake rather then out the oil seals. Path of least resistance


Someone correct me if I’m wrong, I don’t have all the answers just thought I’d spout off this one
_________________
Stuart Zickefoose

2011 Jetta Sportwagen TDi 6 speed manual

206-841-7324
[email protected]

[jtauxe]