Oil leak from pipe above the oil cooler

[911FRANCE]

Hi everybody,
New poster to this forum but an avid reader of all your advices!
I have fixed a 911S 2.7, US spec from 1975.
Rebuilt the 4 brake calipers, clutch tie rod, switched to SSI heat exchangers and SCART super sound muffler, changed most of the gaskets to avoid all these nasty oil leaks, new tires...
I took it out for a ride last week end and had a pretty bad leak on the heat exchangers. The leak was coming from a hose above the oil cooler, sealed with a now cracked plastic cap.
I cannot figure out what this hose is for. Should I seal it?
Any advice is welcome.
Attached is a picture of the culprit.
Have a good day.
Francois

[john walker's workshop]

Perhaps a better picture?

[yelcab1]

That is the duck bill pipe. It is supposed to leak out any oil collected in the air box. Maybe your car is overfilled.

[proporsche]

hi ..yelcab is correct ..but you should also look on the top of your engine if you do not have any oil leaks ther.Oil press switch ,thermostat O ring and maybe breather cover gasket they call it "Triangle of Death " TOD"If you have too much oil build up there ,it will leak to this tube and around it..

Ivan

[Flojo]

by the way, is there any good/better way to secure/mount that breather hose to the nozzle of the breather than just with a clasp?
because, as the hose goes upward, most oil will flow back but eventually past the nozzles edge as the factory clasp doesn't realy do the business of sealing it.

any idea?

[yelcab1]

The hose vents the oil vapor from the oil tank. So it is supposed to flow down into the engine. A good hose clamp just past the ball seals the hose just fine. Sometimes you just need to change to a new hose that is more compliant.

[Flojo]

well, that's why I asked. New hose and clasp didn't help :-(

[Flat6pac]

The hose is the drain for the bottom of the air box.
The oil gets there in fumes from the oil tank, through the curvy hose coming off the oil fill to the air box, right side
The cure, using SC black connector from air flow to throttle body and SC breather hose from oil fill to the backside of SC connector. Fumes will be pulled directly into throttle body.
Bruce

[gomezoneill]

I seen many bad leaks coming from the (worn out) woven fabric breather hose at the top of the engine near the breather cover. I believe Yelcab may be correct (overfilled oil tank).

[911FRANCE]

Thank you for your replies.
yelcab1, it is indeed the pipe coming from the air filter box. I checked and had some oil in the airbox. I will remove some oil from the oil tank.
proporsche, so far so good, no issues with the triangle of death, fingers crossed.
Have a good day!