View Single Post
Old 08-28-2021, 06:14 AM
bill.hutchison bill.hutchison is offline
Join Date: May 2020
Location: Northern VA
Posts: 317
Default 101-Level Errors for August

I might start a series of posts for this: silly mistakes newbie owners make that maybe other newbie owners can learn from.

We'll call this one: "Reading the Torque Chart Carefully."

Y'all might recall a while back that I'd posted about my right brake making the honking sound and not holding under runup power. Braking action was fine for normal ops, just not holding on runup and this was an issue.

So I took the right brake apart and inspected it and noticed some lube/oil on the pins, pressure plate and puck and went "Aha!" I had lubed the pins with LPS and that was likely the wrong lube to use. So I cleaned EVERYTHING up as clean as possible, went ahead and replaced the pads and, since I had it apart, put a new o-ring on the puck since I'd ordered a bunch of spares. Also obtained some proper copper-anti-seize for the pins and put THAT on the pins.

Putting it all back together, I looked up the torque value for the AN-4 bolt,'s like reading a checklist but not processing it, right? Something I tell my students about....

You can see where this is going, right?

Because the HEAD of the AN-4 bolt is 7/16, but the torque values are not for the head....(and yes, I know it says don't use head size, use shank, and I just didn't process this right) so I tried to torque the AN-4 a little past 60 ft/pounds.



Local mech (thank you, Gary) was still in the shop so he was kind enough to show me how to get the bolt out of the pressure plate. I happened to have non-drilled head spare AN4-15A bolts on the bench, so I'm not dead in the water, but new bolts have been ordered.

A lack of attention to detail has gotten many an aviator in trouble. This is a minor annoyance but also a reminder that attention matters.

Mistake made. Lesson learned.
Reply With Quote