Forum: F-16 Design & Construction

just wondering ...

will it cause the entire system to be over pressurized ?

We talking engine oil system? F100 or F110?

Depending on HOW overserviced the system [Link pending approval]

Disclaimer: Always follow tech-data when troubleshooting engine/aircraft discrepancies and/or anomalies .

If a PW-229 is full to the 'overflow' port (like one services the F110) you will see leakage from the #1 bearing in the inlet. F100s like their oil level in a very specific range. This is why the servicing JG specifies NOT to add oil until it is below a specific point, then not fill beyond a specific point. (The overflow is TOO full) In this case oil will leak past the bearings' carbon seals and cause internal/external leakage from the bearing cavities. Typically #1 leaks first and becomes VERY visible to the person performing the inlet inspection.

If the oil system was filled beyond that, the F100 would likely blow the excessive oil out of the breather. This is the part of the system that maintains the proper air pressures in the oil system. It is the 'vent' on the bottom of the engine gearbox that smokes a little while the engine is running. If the oil level is high enough to enter the breather sub-system during operation it will vent from here. This would result in a puddle of oil beneath the running aircraft, or a very wet, oil streaked engine bay when the aircraft returned from flight.

Note: Ever notice how F100 engines that set with full oil systems will begin to loose their oil from the breather? (resulting in a huge oil slick under them) This is due to the oil settling out of the tank and into the gearbox, where it will overflow the breather and begin to drain out of the engine. Proper oil levels should be established prior to running said engines.

Severe overservicing may cause the oil pressure in the system to be high, especially if the oil was affecting the breather causing the air pressure in the system to be incorrect. Remember the breather is responsible for allowing the air pressure in the oil system to change with altitude. Don't want the tank to burst or be crushed by differential air pressures. If the internal pressure of air within the oil system is too high, it could affect the oil's pressure too.

I'll see if I can find some 'reference only' training material on the subject.

In the mean time it would be simple enough to 'de-service' the oil tank sufficiently to eliminate the [Link pending approval] I believe this is in the technical [Link pending approval]

Disclaimer: (Again) Always follow tech-data when troubleshooting engine/aircraft discrepancies and/or anomalies .

Keep 'em flyin'
TEG

that was a very informative post . actually i was referring to the f110 CGB . .
the CGB was over serviced and the decouples would not extend . somebody actually told me that , due to overservicing , there was'nt enough pressure in system to push the decouples out .