HighSchoolBuilders
Well Known Member
Hi all,
I came to the part where I have to torque all the fuel and brake AN fittings. I have been researching on the web as well as all the references out there, they all have different values and I am lost as to follow which to follow.
First, I looked at Van's Manual, under section 5, 5P (pg. 5-7), it says:
1/4" tubing it's 40-65 in-lb.
3/8" tubing it's 75-125 in-lb
Then I look further on Van's website and found a PDF by Aeroquip, and it clearly stated Torque Specification for Al fittings is:
-4 Nut size = 100-140 in-lb
-6 Nut size = 150-195 in-lb
On top of that, it has this Alternate method and when I compare using this method and a torque wrench, it seems like the two do not yield similar results. If I use the alternate method, it appears to be under torque because I can go much further with a torque wrench before reaching the value.
Then on the web, there is the army Chinook helicopter repair manual, which stated
-4 Al hose = 50-65 in-lb
-6 Al hose = 100-125 in-lb
And just to confuse me even further, some values are for lubricated thread and some didn't say the value is lubricated or not.
Can anyone tell me if I am missing something here because I don't think there should be so much discrepancies from difference sources.
Can anyone tells me if they have leak or damage with the value you went with?
Any feedback or suggestion is greatly appreciated!
Cheers!
Hank
I came to the part where I have to torque all the fuel and brake AN fittings. I have been researching on the web as well as all the references out there, they all have different values and I am lost as to follow which to follow.
First, I looked at Van's Manual, under section 5, 5P (pg. 5-7), it says:
1/4" tubing it's 40-65 in-lb.
3/8" tubing it's 75-125 in-lb
Then I look further on Van's website and found a PDF by Aeroquip, and it clearly stated Torque Specification for Al fittings is:
-4 Nut size = 100-140 in-lb
-6 Nut size = 150-195 in-lb
On top of that, it has this Alternate method and when I compare using this method and a torque wrench, it seems like the two do not yield similar results. If I use the alternate method, it appears to be under torque because I can go much further with a torque wrench before reaching the value.
Then on the web, there is the army Chinook helicopter repair manual, which stated
-4 Al hose = 50-65 in-lb
-6 Al hose = 100-125 in-lb
And just to confuse me even further, some values are for lubricated thread and some didn't say the value is lubricated or not.
Can anyone tell me if I am missing something here because I don't think there should be so much discrepancies from difference sources.
Can anyone tells me if they have leak or damage with the value you went with?
Any feedback or suggestion is greatly appreciated!
Cheers!
Hank