Engine driven fuel pump inlet fitting torque

[jcbarker]

This is one of those fittings with straight threads and an O-ring. I ran it snug up against the body of the fuel pump. when the hose is attached it can still rotate a bit so I put a wrench on it when I tightened the hose nut. Is this normal or am I missing something?

 

[jcbarker]

Here's a screen grab from the KAI:

 

[Walt]

This is one of those fittings with straight threads and an O-ring. I ran it snug up against the body of the fuel pump. when the hose is attached it can still rotate a bit so I put a wrench on it when I tightened the hose nut. Is this normal or am I missing something?

No not normal, fitting should not rotate in the pump.

 

[Taltruda]

Hold the inner fitting with one wrench, then using another wrench, snug up the outter nut (that presses the washer into the O-ring). Nothing should move when it’s done.

 

[jrs14855]

Rocket fatal and an RV fatal caused by that nut not being properly torqued. Several others where the jam nut was the likely cause. In some cases not enough left for a definitive finding.

 

[jcbarker]

Hah! That's the problem. This fitting didn't have a washer like the fitting on the other side of the pump! Must have fallen off.

 

[Walt]

This fitting does not use a washer if that is what you have.



The style below is the type that uses a washer

 

[wirejock]

There is another one on the fuel servo on the IO-360-M1B. I was wondering what the torque should be on the nut as well.

 

[jcbarker]

Yep, that's the one. So just get it tight against the pump body and put the hose on that fitting first. Then route it around to the firewall fitting?

 

[Walt]

Yep, that's the one. So just get it tight against the pump body and put the hose on that fitting first. Then route it around to the firewall fitting?

The fitting in the pump is TIGHT! when you tighten down the fuel line fitting it also gets VERY tight, neither should move obviously when you're done.
If you're not sure, it might be wise to ask someone or an A&P type. Fuel system is serious business.
Don't know what the torque 'spec' is but if you're average strength then probably about as tight as you can get it with 11/16 wrench.

 

[Dougnabbit]

Or read Manual Section 5 provided to you by Van's!

 

[TS Flightlines]

The fitting in the pump is TIGHT! when you tighten down the fuel line fitting it also gets VERY tight, neither should move obviously when you're done.
If you're not sure, it might be wise to ask someone or an A&P type. Fuel system is serious business.
Don't know what the torque 'spec' is but if you're average strength then probably about as tight as you can get it with 11/16 wrench.

300-340 IN LBS---but tight so it doesnt move, or leak. Angled versions, screw the fitting into the port until it almost bottoms out, or until the proper orientation is reached, hold it with a wrench, then tighten the lock nut/washer/oring. I use a longer wrench on those to get it tight. YMMV.
Tom

 

[jcbarker]

300-340 IN LBS---but tight so it doesnt move, or leak. Angled versions, screw the fitting into the port until it almost bottoms out, or until the proper orientation is reached, hold it with a wrench, then tighten the lock nut/washer/oring. I use a longer wrench on those to get it tight. YMMV.
Tom

Thanks Tom! I'll double check the torque. I just used my "Armstrong" torque wrench

 

[mcgaughy]

This is one of those fittings with straight threads and an O-ring. I ran it snug up against the body of the fuel pump. when the hose is attached it can still rotate a bit so I put a wrench on it when I tightened the hose nut. Is this normal or am I missing something?

When I want to be precise and can't find in literature, I contact the manufacturer.... in this case, the fuel pump manufacturer. As I recall, this particular fitting is a much higher value than one might expect but I don't recall the exact value.

 

[mc607]