Dipstick o-ring

[Duane Baker]

I need to use a pair of pliers to unscrew the dip stick, once it moves it's ok, not the threads.  My AP says to replace the o-ring, he says they get hard and stick. Does anybody know the part number? I can't find it on my parts CD.

[DualRatedFlyer]

https://www.aircraftspruce.com/catalog/eppages/lycominggaskets_08-00307.php

[OR75]

never a bad idea to change an O-ring but honestly, if you had to use pliers, it is because it was tightened too much. There is no reason to tighten the dipstick.    

[Hank]

The dipstick will get tighter when the engine runs. I snug mine down gently, and have no trouble opening it; if I crank it closed, it's very difficult to open. 

[Skates97]

55 minutes ago, Hank said:

The dipstick will get tighter when the engine runs. I snug mine down gently, and have no trouble opening it; if I crank it closed, it's very difficult to open. 

Agree 100%. It took me some time to figure out just how snug I needed it to be to not come loose and also not be difficult to remove.

[jaylw314]

2 hours ago, OR75 said:

never a bad idea to change an O-ring but honestly, if you had to use pliers, it is because it was tightened too much. There is no reason to tighten the dipstick.    

I was taught to turn it a half-turn in my ground school, but my instructor pointed out that if I don't tighten it enough, in most aircraft it's not going anywhere with the oil filler door closed.  I've also had the oil filler neck come off in my hand with a tight dipstick in our old club Cherokee (it wasn't safety wired down at the time).  Now it's probably just snug and then an eighth turn more

Edited June 10, 2019 by jaylw314

[N201MKTurbo]

When I have an FBO add oil I always tell them to just drop the dipstick in and not even screw it in. I make them acknowledge the instructions.

when I get back to the plane it is always cranked down hard. I should start leaving it in the baggage compartment.

[RLCarter]

In till it touches, then 1/8th turn, no way I could get a 1/2 turn on mine without tools, a full 1/4 turn by hand would be difficult 

[Duane Baker]

Thanks guys, I will not tighten as much and I'll get the o-ring. Cheapest Mooney part yet. Duane 

[ArtVandelay]

I only use the edges on tightening, prevents over tightening because my fingers slip.

 

 

Tom

 

[Hank]

1 hour ago, N201MKTurbo said:

When I have an FBO add oil I always tell them to just drop the dipstick in and not even screw it in. I make them acknowledge the instructions.

when I get back to the plane it is always cranked down hard. I should start leaving it in the baggage compartment.

No FBO ever adds oil to my plane. Sometimes I will buy a quart, but I add some or all of it myself. Often half a quart. 

[carusoam]

For comparison...

Continental has a stop on the oil cap... it can only be twisted so far...

Thread designs have come along way since the 60s...

I have also loosened the plastic oil tube on the O360. 

Best regards,

-a-

[jaylw314]

10 minutes ago, carusoam said:

I have also loosened the plastic oil tube on the O360. 

That was the week after I got my ticket.  I signed on with a flight club, got checked out, preflighted for the first time and "pop!"  Off comes the filler tube in my hand.  Too bad nobody took a picture of my facial expression 

[N201MKTurbo]

4 hours ago, Hank said:

No FBO ever adds oil to my plane. Sometimes I will buy a quart, but I add some or all of it myself. Often half a quart. 

I hear ya, but most time I fly is because I'm in a hurry.

[Hank]

2 hours ago, N201MKTurbo said:

I hear ya, but most time I fly is because I'm in a hurry.

A one-hour flight LOP vs ROP will cost more time than it takes to top off the oil yourself. I'm never in that much of a hurry.

Edited June 11, 2019 by Hank

[PT20J]

The Lycoming tube is plastic. The threaded end of the dipstick is metal. Crank it tight and the plastic threads deform and seize the dipstick. I've seen them so tight on flight school and rental airplanes that I needed pliers to get them loose. Just tighten them snug -- an eighth to quarter turn is plenty. I forty years, I've never found one loose after a flight.

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