free website stats program OIL leaking from Breather vent | Page 2 | Harley Davidson Forums

OIL leaking from Breather vent

Well I've ridden the bike a little more and now I see that there's oil coming somewhere out of the front cylinder head area and the primary cover has a mist of oil on the top of it and the horn cover has oil on it. I just wonder why the leaking starts now after running the bike for 1,500 miles or so last year without any problems. I run it less than a hundred miles this year so far and there's an oil slick starting to cover most of the engine area. I kept the bike in a heated area all winter.
 
It could be possible the rocker box gaskets and umbrella valves(head breather) have dried out a bit since it is a 10yr old bike with 1500 miles on it. Switching to syn oil won't cause a leak but it will show imperfections in gasket sealing as a leak/weep that fossil oil won't.
Warm up the Evo before taking off or you could wind up with base gaskets leaks too.
 
When synthetic oils first came around I remember hearing that with older engines the synthetic oil would leak out of an older engine quicker, than being consumed. I wondered if my situation might be this type of problem, it's just leaking through stuff because of the characteristics of synthetic. I checked a few things to see if there might be something loose but everything is tight. I'll make sure it's warmed up before heading out. Thanks for the info. I may have to go back to the Harley 20-50 or have the top end rebuilt. I just don't understand why it starts bothering now after the synthetic's been in it for 1,000 miles or so.
I"m going to change the umbrella valves because that's where all the oil is coming from. I'll do the rocker covers too.
 
Last edited:
Synthetics causing a leak is a myth. However synthetics tend to clean sludge so If there is a sludge plug then it may be possible for it to clean it and then a leak may result. ie sludge on inside of a main seal if cleaned off may cause oil to leak.
 
I replaced the umbrella valves and all the rocker box gaskets but that didn't help stop the leaking. I'm going to try a different type of air cleaner set up next.:eam
 
Here's a thought.....your bike isn't ridden much, when Evo Softails sit a lot oil will weep by the check ball in the oil pump into the case...on start up it will puke oil out of the breather vent and now that your running syn oil a little oil is weeping past the check ball on shorter layoffs giving you a heavier mist from the breather vents....maybe you could check in to having the check ball reseated.
Sorry about the bad info on the rocker gaskets and umbrella valves, there isn't a lot of places on the left side of the engine to leak oil onto the horn cover...that's what made me think gaskets.
 
Yeah I did this morning.....I think he must have it sorted out by now...maybe White Mts. Rider could start his own thread
 
I installed a Ness stage 1 big sucker this past week and noticed that there is a bit of redish oil dripping down on the timing cover.Bike is a 07 tour classic with TFI and rush slipons.I treated the filter with the oil spray but not that much.Any ideas?
 
Too much oil on the filter. You should only spray a line around the center of the filter and let it wick out to the rest of the filter.
 
Back
Top