What does a crankshaft breather do?
When the vehicle is moving, airflow across the open end of the tube creates suction (a “draught” or draft) that pulls gases out of the crankcase. To prevent a vacuum being created, the blow-by gases are replaced by fresh air using a device called a breather. The breather is often located in the oil cap.
What happens if you leave the crankcase breather on?
These gases then cause a pressure build-up in the crankcase, which if went unattended, can cause serious problems like gasket leaks, the engine burning oil, or even worse damage the engine. To paint a picture, imagine an air compressor pumping air into a sealed container of engine oil all the time.
Where does the oil come from in a crankcase breather?
Low and behold, the leaking engine oil was coming from the lower part of the breather and was dripping on to the crankcase. The PCV valve (positive crankcase ventilation valve) is a crucial part of the system as it controls the flow of crankcase gases entering the intake system.
What can cause 1989 Harley pukes oil out crankcase vent?
Re: 1989 harley pukes oil out crankcase vent when started… Blow by compression. Severe engine problems. Pull the heads look at cylinder walls You can’t post conmments that contain an email address. I have 1983 Harley Sportster 1000 that won’t fire when I first turn the key, but after a few minutes it fires right up what can cause this?
When did oil start leaking from Breather vent?
Discussion in ‘ Oil ‘ started by dontask, Aug 16, 2008 . I have a Hearitage Softail CLassic 1991, this year we have not done much riding weather been really rainy.
What causes a Harley Davidson crankcase breather to leak?
Partially restricted pushrod tubes. Improper oil pump timing. Improper head venting. Excessive blow-by due to worn rings. Also, one other thing that can cause it, if none of the above fixes your problem. Ive had the stock plastic crankcase breather valve shell out and cause excessive oil blowby thru the breather.
Is it possible to repair a crankcase breather?
Complete replacement is emphasized much more than repair. Such is the build and the price of them. You can perhaps dismantle and clean it but returning the parts in place without breaking them and not having leaks seems pretty unlikely.
Re: 1989 harley pukes oil out crankcase vent when started… Blow by compression. Severe engine problems. Pull the heads look at cylinder walls You can’t post conmments that contain an email address. I have 1983 Harley Sportster 1000 that won’t fire when I first turn the key, but after a few minutes it fires right up what can cause this?
Low and behold, the leaking engine oil was coming from the lower part of the breather and was dripping on to the crankcase. The PCV valve (positive crankcase ventilation valve) is a crucial part of the system as it controls the flow of crankcase gases entering the intake system.