Pre-purchase inspection checklist for M-4

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Jupton
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Pre-purchase inspection checklist for M-4

Post by Jupton »

Does anyone have a pre-purchase checklist for the M-4,they’d share?
Any specific items/areas I should pay particular attention to?
I know everyone will advise getting an IA with Muale experience, but I don’t have the time to locate one and I’ve bought/inspected several cessna’s on my own and done well. Just not familiar with the Muale’s.

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Mog
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Re: Pre-purchase inspection checklist for M-4

Post by Mog »

Well, where is it? What engine?

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Re: Pre-purchase inspection checklist for M-4

Post by Jupton »

Cincinnati, 0-300

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Mog
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Re: Pre-purchase inspection checklist for M-4

Post by Mog »

Well dang, I’m not up on the O-300. And I’m way to far from Cincinnati.

It an airplane, not much to it really. I would check for a rusty frame, bent tubes and corrosion in the wings. The engine is nothing special, any decent A&P can inspect it.

I’m not going to state that I’m overly qualified to give advise, but here is what I have

Flight surface bushings (loose or spinning)
Flap stops feel loose
Flap pushrod attach point bending/failing
Rust on frame. Look as far back as you can
Tail spring
Tail wheel assembly
Bent main gear (May be hidden damage)
Toe adjustment (bitch to control if wrong)
Damaged oleo bolts (top and bottom)
Oil level in oleos
Cables properly run (often they are wrong it seems)
Wood stringer condition or metal conversion
Doors close and latch properly (Maules are finicky)
The list of course goes on and I can name everything. But that is a bit of a list I would knock out for sure on top of typical stuff.

Post up a pic and maybe someone knows the plane. If this is a newer M4 then I would expect you are in very good shape, but if it’s a vintage model then give it a good hard look.

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Re: Pre-purchase inspection checklist for M-4

Post by MauleWacko »

:shock:
Last edited by MauleWacko on Thu Oct 07, 2021 7:09 am, edited 1 time in total.

Hale-Yes
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Re: Pre-purchase inspection checklist for M-4

Post by Hale-Yes »

Wacko, I think that you mean "Turd". You do have a way with words! :D :D :D
"The problems we face today exist because the people who work for a living are out numbered by those who vote for a living" Author unknown.

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norcal64d
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Re: Pre-purchase inspection checklist for M-4

Post by norcal64d »

I would suggest pulling the seats and floor out of it as part of your prebuy if you weren't already planning on it. It takes a bit of time to get the floor up but its much easier to see the cables and frame under there with it out. Make sure the oil is topped off in the oleos and then check back the next day to see if there is a puddle of oil under the plane. Changing the orings in the oleos is fairly time consuming and honestly a real pain. Pay close attention to the exhaust system checking for cracks and definitely pressure check it. Check the logs and if its been more than a couple years since the NAS upgraded landing gear bolts were installed, I would definitely put new landing gear bolts in. I have been told an easy check is to back off the torque on the bolts and rotate them and check for a wiggle that would indicate a bent bolt.
Tim
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Mog
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Re: Pre-purchase inspection checklist for M-4

Post by Mog »

Shouldn’t need to back off the Oleo bolts to check. Just rotate the bolt head with a wrench and you will either note that the shock doesn’t move or it cause the bushing to move up and down due to the bolt being eccentric. They are a pain to remove if they are to far gone.

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norcal64d
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Re: Pre-purchase inspection checklist for M-4

Post by norcal64d »

Mog wrote:
Sun May 23, 2021 3:47 pm
Shouldn’t need to back off the Oleo bolts to check. Just rotate the bolt head with a wrench and you will either note that the shock doesn’t move or it cause the bushing to move up and down due to the bolt being eccentric. They are a pain to remove if they are to far gone.
Smart, I like it. I had to pull my oleos out on my last annual so I never actually checked to see if they were eccentric prior to removal.
Tim
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andy
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Re: Pre-purchase inspection checklist for M-4

Post by andy »

I imagine that the M4 has similar main gear leg attachment points to other Maules. If so, then the main gear leg front and rear attachment bolts need to be rotated to check if they are deformed. If the bolts don't rotate freely, then they are either deformed and ready to shear or they are seized up. Either way, they need to be replaced.
Andy
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Re: Pre-purchase inspection checklist for M-4

Post by maules.com »

To check the upper oleo attach bolts for distortion, one must loosen the nut a tad so as to be able to turn the bolt by its head.
This nut and bolt have an important tightening torque to be reset after checking the bolt.
If the torque is not enough, the bolt will not be supporting a shear but rather a bending action.
There is a shim on each side of the bearing in the oleo top .
If the bolts are removed or replaced then correct thickness of washers need to be used so one is not tightening uo against the bolt shank.
The airframe/oleo attach lugs are slightly spread so the oleo and two shims can easily be slid into position, thus part of the nut tightening is squeezing the lugs against the shims and bearing.
Threads in the nut and on a bolt stretch so important to torque at each inspection or replacement.
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Re: Pre-purchase inspection checklist for M-4

Post by Jupton »

Thanks for all the replies and insight. I bought the airplane! The only squawk on the 8 hour flight home, 8 hours because I stopped several times along the route to practice tail wheel landings with my instructor, was while running on both tanks it drawing almost exclusively from the left tank. Any insight in this group about a fix? Previous owner replaced the gas caps, but the vent is facing aft, instead of fore as I would expect to see. The caps only fit on in one direction.

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Mog
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Re: Pre-purchase inspection checklist for M-4

Post by Mog »

Maybe you were flying wing high a bit? 🤷‍♂️

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andy
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Re: Pre-purchase inspection checklist for M-4

Post by andy »

They all draw fuel unevenly from both tanks but not usually with that much difference. Was the ball centered? Is the ball centered with the right rudder trim handle about half-way out? Maybe a rigging issue. Another possibility is a blockage in one of the main fuel vents, like a wasp or spider's nest. Carefully run some safety wire into the vents to make sure they're free.
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Re: Pre-purchase inspection checklist for M-4

Post by maules.com »

Tank cap vents should face forward for ram effect otherwise low pressure aft of vent tube cases fuel to evacuate. Are they clear ?
It is a longer run fuel line from right inboard tank than left inboard tank thus more drag and slower feed.
Do yo have Left, Right, Both, and Off fuel selector. Its a recommended upgrade because if no Both, while flying on Left or Right with low fuel its a skid maneuver it is easy to unport the fuel tank outlet and starve the engine.
Fuel can crossfeed when selector is Off, or Both.
Do you have long range aux tip tanks?
Jeremy
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