Oil system manual for a 1987 softail (evolution). oil leaking from breather of engine system.

Hi, Anonymous and the usual suspects are:
1. Oil tank/system overfilled.
2. Faulty breather valve.
3. Engine breather hose bent, pinched, kinked etc.
4. Air filter has too much "pre-oil".
5. Crankshaft seal failure allowing transmission fluid to migrate.
6. Blow by drain tube cracked/split or filled to capacity.
For more information about your question and valuable "FREE" downloads that you will need please click on the blue links below. For more information please contact me at [email protected]. Good luck and have a wonderful day.
https://www.youtube.com/watch?v=aF09112Wa94
http://www.mediafire.com/file/65o6mbkdq5ty8ke/99_to_05_Harley_Softail_Service_Manual.pdf/file
https://partsfinder.onlinemicrofiche.com/ronnies/showmodel.asp?make=hdmc
https://serviceinfo.harley-davidson.com/sip/content/document/view?id=58666
https://www.6ya.com/ to speak to me personally

Hi, Anonymous and the usual suspects are:
1. Oil tank/system overfilled.
2. Faulty breather valve.
3. Engine breather hose bent, pinched, kinked etc.
4. Air filter has too much "pre-oil".
5. Crankshaft seal failure allowing transmission fluid to migrate.
6. Blow by drain tube cracked/split or filled to capacity.
For more information about your question and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.
https://www.hdforums.com/forum/softail-models/827141-oil-leak-oil-drain-hose-on-deuce.html
http://www.mediafire.com/file/65o6mbkdq5ty8ke/99_to_05_Harley_Softail_Service_Manual.pdf/file
https://partsfinder.onlinemicrofiche.com/ronnies/showmodel.asp?make=hdmc
http://mybikemanuals.com/harley-davidson/
https://www.6ya.com/

Shooting oil? Your engine is what we refer to as a "head breather". This is because the crankcase pressure is vented into the carburetor, by EPA requirements, through the two large hollow bolts on either side of the breather backing plate. They may be covered by rubber plugs but you can see them when you take the air filter off. Oil accumulation is normal but "shooting" is not. This would indicate a excessive buildup of oil in the rocker boxes and failure of the "umbrella valves" in the center section of the rocker box covers. I'd take the air filter cover off and clean it out thoroughly and see if it still did it. If so, you've got a problem with the crankcase venting system on the engine. Since I'm not that familiar with the Twin Cam engine, I'm reluctant to guess exactly what the problem is. In the older Evolution engines that I'm familiar with, I'd suspect the "breather gear" in the cam chest but I'm not sure the TC-88B engine uses this system. Sorry I can't be more specific.

good luck
Steve

I've run into this problem before. Unfortunately, the owner wrecked the bike before we solved the problem. Here's what I found so confusing. If the top end is filling up with oil and not draining down the return holes in the heads and cylinders, it should drain down through the pushrod tubes. Each tappet has a drain hole in the tappet block to allow oil to drain down and not build up in the tubes. But, for some reason, it seems that the oil simply will not drain back. It acts like there is too much pressure building up in the crankcase. It wouldn't do it on short rides, just on rides of about 20 miles or more.

So, with this in mind, my next step was to pull the nosecone and check the breather gear. As you know, the Evolution engines have plastic breather gears in them and I've seen lots of them break a tooth and quit turning. Usually, the broken tooth gets hung in the return gears of the oil pump and shears the drive key. This requires that this be fixed before the engine can be run and the pressure build up noticed. But, if the broke plastic gear tooth does not lock up the oil pump, the breather gear not turning could be the reason for the pressure buildup in the engine. Now, you cannot simply take the bolts out of the nosecone and pull it off. You must deal with the ignition system first then the cam and tappets. The book says that you must pull the pushrods out and take the pressure off the cam or you will not be able to get the nosecone back on. If the breather gear is broken, you'll have to retime the new one and the cam unless you replace it with one of the new S&S Reed Valve type breather gears that do not turn.

Now, this is just a guess on my part. Since I cannot see or touch your engine, this is the only idea that I know of provided the oil pump is pumping the oil back into the oil tank. It's your engine blowing oil out for no apparent reason. I had the problem on a '91 FXR which is not a head breather. It just leaked oil from everywhere. pushrod tubes, rocker box gaskets, base gaskets, everywhere. I'd like to know what you find.

Good Luck
Steve

Rick, since 1994, Harley has used what we call a "head breather" system in that the crankcase breathers are located in the heads. This was done in an effort to reduce the amount of oil that gets into the air filter. In earlier case breather model engines, the oil would pour into the air filter if the bike had been sitting for a few months. Prior to that, the bike would "puke" what looked like a quart of oil on the ground below the bike when first started after a long period of sitting.

If you'll remove the air filter cover and element, you'll see that the large bolts that hold the breather onto the heads are hollow. Inside the rocker boxes, there are small rubber "umbrellas" that are opened and closed by crankcase pressure. These are designed to allow your engine to breathe without an excess of oil being blown out. Still even though this system is better, a little oil still gets into the air filter. You can either keep this cleaned out or you can replace the "head breather" systems with an aftermarket system that changes the location the system exhaust crankcase pressure from. Also, you can change the "umbrella" seal and put in new ones. It isn't that difficult to do on the front head. The rear head can be tricky since there isn't much room to get to the bolts to take the rocker box cover off. The umbrella seals are located in the center section of the rocker box cover.

Good Luck
Steve

check the oil level fuel may have leaked into the sump.

This is almost always the pressure sending unit for the oil pressure gauge. It is located at back topside of the motor, slightly to the right of the center of the engine. It is buried beneath the intake manifold.