searching for the word "hose" just didn't seem like a good idea, so hopefully somebody has a quick answer...

never noticed it until this week (as far as leaking)...but there's a fitting coming out of the block, near the firewall on the driver's side of the motor...attached to it is a ~1" diameter hose, that goes straight down and has no end on it, just like a overflow hose or drain hose...

several days over the past couple weeks, I notice there's a spot about the size of a silver dollar directly underneath it, and it appears to be oil...

what's the hose for? and why does oil come out of it? and I guess more importantly, does something need to get fixed?

Thanks.
Greg

 

I think your talking about the breather tube. unclemarc

 

Yup, it's the blowby tube, or crankcase vent, if you prefer. Cummins specs an allowable amount of blowby, though I don't know the figures or how to measure them...guess I'm pretty worthless here Mine lets out a nice mist after a hard pull; I've read that's normal.

 

so, just normal wasted oil in a CTD?

I had just topped off the oil (best I can recall) the day before it started, so maybe I put just a bit too much...

I'd just never noticed it before, unlike the other fluid spots I'm used to...

Greg

 

Yup it is common..

Mine does the same.. but usually like above I see a bigger drop on ground after I have been towing for a while..

in day to day driving I usualy see nothing from there.

 

That's what i was going to suggest!

The proper way to check your oil is the let it set for.... 10 min. or so and then check the dip stick......this will keep you from adding that extra Q or 2,of oil, that you don't need!

Try it and you will see for your self.

shut the eng off, jump out and check your oil, then,..... what 10 min. and check it again. you will find that Q of oil that you thought you needed or had lost

 

I wouldn't worry too much, it is all part of the 1st gen external lubrication system.

 

yup thats normal real engine have those but if it starts sputerring too much oil your in trouble

 

so I guess there's no valve or anything inside there that can go bad?

it's kinda like a vent tube on a diff?

Greg

 

exactly.....

 

and even more like the 'standard' issue crankcase vent tubes on engines, even into the early 60's. My late '50's small block chevys had them. I still use them on a few cars that have blow-by problems and oil fowls the intakes (i.e. some VW's with 300k + on them (Gassers !!)

I cut a nice 30 deg angle just like the tube of ole days, so there is some extra 'vacuum' at road speed

You should keep an eye on it if you are not overfull, using correct viscosity, and not towing heavy. You can search the links for a compression tester, as that would indicate the health of engine. You can use a little (very little) oil in weak cyl to determine of it is valve issue or rings,

BTW, how is the valve / head life on these guys? (stock to mild bomb, not 'twins and gas injection' ) (in my dreams... this is still my primary work truck and it pukes a bit of oil out the 'breather' after pulling a 10% grade @ 28,000# GCVW, ...every day on the way home)

 

If you want to keep the transmission area clean and free of sludge, slip a 5/8" heater hose coupling on that and extend 6' of 5/8" oil resistant hose towards the rear of your truck, drivers side, and point it down about 5" past the bottom of your frame. Did that a while back and transmission areas are spotless. If anything, it will make future possible transmission/rear main seal leaks easier to diagnose by ruling out the brather hose.