CC-340 Crankcase oil seal

[seguind]

Has anyone had problems with the Crankcase Oil Seal on a CC 340? The engine has 100 hours and a balanced prop. There’s oil up on the front of the cowl and front engine parts but I’m not sure it’s from the oil seal. I checked all the usual suspects but no signs of a leak. It seems odd that the seal would start to fail after only 100 hours. I’m curious if anyone else has had this issue before I pull the prop, put in a new seal, etc.

[Andy]

When I received my FX-3 I was cautioned that the crankcase breather tube in the exhaust system must be kept clear. Does your engine have this breather arrangement? If so, have you kept it clear?

[aeroaddict]

As Andy has stated, the exhaust breather tube requires cleaning about every 100 hrs (EX-2). If this gets plugged, then you can see increase crankcase pressures and possibly oil blow by at the seals.

I don't know about the FX-3 configuration, but on the EX-2 it is easy to clean. I use a rifle bore brush cleaning rod with a 45 cal brush on the end, use a small battery powered drill to clean it out. Look up the exhaust stack and right in the middle is the breather outlet.

Let us know what you find out as the front seal should go longer than 100hrs as you know.

[40m]

Technical Publications
SI0023 Breather Tube