Crankcase Vent - Leaking oil when hot?
Crankcase Vent - Leaking oil when hot?
XLCH '71
After about 10 miles down the road, my crankcase vent that goes into the bottom ofthe oil tank and then out of the top of the tank through a hose,ispuking out oil. It seems that it only does this when the engine get´s hot... Smaller trips say 5 miles or so, it does not leak before I turn of the engine... Any ideas?
After about 10 miles down the road, my crankcase vent that goes into the bottom ofthe oil tank and then out of the top of the tank through a hose,ispuking out oil. It seems that it only does this when the engine get´s hot... Smaller trips say 5 miles or so, it does not leak before I turn of the engine... Any ideas?
Stellar HDF Member
Joined: Feb 2006
Posts: 3,035
Likes: 17
From: Houston Texas
RE: Crankcase Vent - Leaking oil when hot?
W-haaat? You have me really stumped with that one. The crankcase vent hose does indeed go into the bottom on the oil tank, but inside there is a stand pipe that ends a half inch or so from the tank top. This puts the open end above the normal oil level inside the tank and functions as a vent.
What puzzles me is you talking about having a hose running out of the oil tank.
I have never seen that before. The reason for the stand pipe is to be above the oil level and act as a vent, but at the same time, any oil expelled out of the stand pipe just falls back into the oil supply. Maybe you have some kind of aftermarket oil tank? Or do you have a side mount tank? It may well be that a side mount tank has this vent connection. My 1971 has the center mount tank and there is no outside connection for a vent............pg
What puzzles me is you talking about having a hose running out of the oil tank.
I have never seen that before. The reason for the stand pipe is to be above the oil level and act as a vent, but at the same time, any oil expelled out of the stand pipe just falls back into the oil supply. Maybe you have some kind of aftermarket oil tank? Or do you have a side mount tank? It may well be that a side mount tank has this vent connection. My 1971 has the center mount tank and there is no outside connection for a vent............pg
Road Master
Joined: Mar 2006
Posts: 775
Likes: 2
From: OC California
RE: Crankcase Vent - Leaking oil when hot?
No open lines on a 71 side mount either. Three hoses Bottom = feed to pump. Middle = vent from engine. Top = return from engine. I need some further information.
RE: Crankcase Vent - Leaking oil when hot?
I have thecenter mounted tank.
Embedded 2 pics...
I forgot to mention that there was an external filter on it when I bought it. I have removed it, and set it up to how it wasorginally I think?
Also doublechecked every hose line...
[IMG]local://upfiles/37704/8DEE761338DE4030ACF84C67888F42EE.jpg[/IMG]
[IMG]local://upfiles/37704/BA6DEFC5135242968357796B70132664.jpg[/IMG]
Stellar HDF Member
Joined: Feb 2006
Posts: 3,035
Likes: 17
From: Houston Texas
RE: Crankcase Vent - Leaking oil when hot?
mk2007...
What you have looks OK. You have the return line connected close to the oil filler hole. I choose to connect the return to the far side of the tank on mine, but either way will work.
Inside the center tank both connections are the same. Both have standpipes of equal length and diameter. The open ends of both stop about a half inch from the top of the tank. You will not ever see much written about this and in fact you cannot even see the standpipes while looking with a flashlight, but they are there as I describe and are both the same. So you are good to go.
I think removing the oil filter was a fine idea myself. It cleans up the bike and puts it the way it was from the factory. Just change the oil on a regular basis......pg
What you have looks OK. You have the return line connected close to the oil filler hole. I choose to connect the return to the far side of the tank on mine, but either way will work.
Inside the center tank both connections are the same. Both have standpipes of equal length and diameter. The open ends of both stop about a half inch from the top of the tank. You will not ever see much written about this and in fact you cannot even see the standpipes while looking with a flashlight, but they are there as I describe and are both the same. So you are good to go.
I think removing the oil filter was a fine idea myself. It cleans up the bike and puts it the way it was from the factory. Just change the oil on a regular basis......pg
RE: Crankcase Vent - Leaking oil when hot?
Thanks for that info piniongear.
So the top hose, can Ijust block it, and does somebody know why this should leak oil?
So the top hose, can Ijust block it, and does somebody know why this should leak oil?
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Stellar HDF Member
Joined: Feb 2006
Posts: 3,035
Likes: 17
From: Houston Texas
RE: Crankcase Vent - Leaking oil when hot?
I think it is OK to block it. Can you post a pic of this top connection and your oil tank so we can see what you have?
I could then make a better recommendation perhaps........pg
I could then make a better recommendation perhaps........pg
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Stellar HDF Member
Joined: Feb 2006
Posts: 3,035
Likes: 17
From: Houston Texas
RE: Crankcase Vent - Leaking oil when hot?
This is a vent connection someone added to a factory center mount oil tank. It is not needed, so cap it off right now. That's what causing the oil leak. This vent is located right above the oil pump breather tube connection standpipe (center connection on the oil tank bottom).........pg