WSUCougarx's M561 Gama Goat Acquisition and Build Thread

[wsucougarx]

Army Be All That You Can Be commercial

Gama Goat!
https://www.youtube.com/watch?v=E_OCDJIT344

 

[Another Ahab]

Gama Goat!

Good catch! I remember that ad for sure.

 

[wsucougarx]

Where is the coolant going?

A couple days ago, I decided to check all the fluids. I wasn't planning on taking her out nor did I really have any concerns. Just thought it would be a good thing to do. Everything looked good until I got the the coolant. I had to grab the flashlight to see where the top of the coolant level was. What?!? It was about 4-5 inches lower in the overfill tank than usual. So immediately chicken little got the best of me. Did I warp the o-rings? Was the fluid leaking out the airbox drain? Where my liners shot and all the coolant is now in the crankcase? It's amazing how ones mind can jump all over. I walked over to the driver side to look at the crankcase level again only to see a wet tub just under the engine. I checked the airbox drain tank...nothing. I checked all the hoses...nothing. Hmm, so I fired up the 353 and waited to see what was going on. Luckily it was coming from the radiator!!! I dismantled the braces and took the radiator cross member to get a better look. There was apparently a small hairline crack at the top of the radiator at a crease point. When I first got this radiator from Saturn Surplus, I had two areas of concern where the radiator was mishandled. After performing the initial air/soap bubble test, she checked out and I mounted her. Apparently after driving her a handful of times, it was enough to open up the crack. If you haven't soldered a radiator it's pretty straightforward. I had a bag of supplies leftover from my '68 M35A2 radiator repair.
So the first thing you've got to do is removing all the panels and hardware to get to where you need to go. Then you've got to drain enough coolant to get it below the area you're going to solder (if you don't, the metal will never get to the temperature you need to solder), clean up the area really well, apply flux, torch and solder. Do not hold the flame over the area for a prolonged amount of time or you'll have a larger hole to deal with. All in all, the actual soldering only took 5 or so seconds. Before you put everything back together, refill with coolant and start the engine. No leaks? Then you're good to go to put everything back on

 

[Another Ahab]

Edit

 

[wsucougarx]

Intermittent Rough Idle issue

The last time I took the Goat out, my wife and I went to the grocery store. Along the way, I noticed the Goat wasn't sounding or running right. Felt like a loss of power and the engine sounded like she was up against the governor. Hmm, I thought it may have been a fuel issue. So yesterday I changed out the fuel filters. I examined the fuel filters and they were clean with no issues. I was confused. One minute she ran awesome then ran like crud. So I restarted her to idle her to check for a radiator leak. She was running great then I moved the accelerator. Right out the corner of my eye, I saw a nice light blue light coming from under an alternator screw on panel. Right when I saw the light, she stated to run rough once again and sounded like crap. So I shut her down and removed the said screw on alternator panel. Hmmm, that's peculiar. There was a nut missing from inside the panel causing the wire loop to arc. Hopefully that was the reason for the loss of power and sounding like crud.
9,377

 

[m38inmaine]

The 3-53 requires no power to stay running, it's all mechanical, once the starter gets her going it doesn't care about power. That wire is the sense wire for the alternator, it tells the alternator to "turn on". Being loose it may have been turning the alternator on and off causing the engine to "lug" as it came on.

 

[BillIdaho]

And thereby ruining the alternator? Or flywheel?

 

[Jericho]

?

 

[m38inmaine]

I don't think it would damage either, the worst it might do is arc weld the stud a little bit.

 

[combat32]

I welded a 1/2 inch wrench to the floor of my bradley once
while disconecting the batteries

 

[wsucougarx]

Well that didn't work. She immediately idled rough and quit. As things would have it, batteries went dead from not charging all this time. Back to the drawing boards. I still need to remove the valve cover anyways. I've been wanting to check the valves. Will keep this thread posted.

 

[m38inmaine]

I was mistaken on the wire identification, after looking closer at the picture the wire that was loose is the + connection, the smaller wire with the Packard connector is the sense wire. Still same outcome as reported before, no fault of the electrical system will cause your engine to run poorly, good luck finding the cause.

 

[combat32]

Have you lost prime in the fuel system, would explain much.

 

[wsucougarx]

Have you lost prime in the fuel system, would explain much.

Hey Tom, after thinking about it all night, everything seems to point to fuel issues. One my last trip out (loss of power trip), whenever I accelerated I heard a different sound that I've never heard before. At the top of the acceleration, I could hear the engine pulsing like she was up against the governor. Not sure if that is a normal sound but on the last 4-6 trip out, she never did that. Normally, the RPMS would just top out with an even rev sound without the pulsing cut of RPM sound. So what's the normal top end sound for you guys?
This may be completely unrelated, the only thing different I did with the Goat before this last time out, was I shut the petcock on the air reservoir. Up until this point, the air reservoir petcock was open.

 

[combat32]

Might check the fuel pump, might be time for a rebuild.

 

[wsucougarx]

Fuel Pressure Gage Options???

Before I get going on breaking down the fuel system, I've been wanting to install a mechanical fuel pressure gauge off the secondary fuel filter canister. With this current issue that's going on, this project is being moved forward. I've been wanting to be able to monitor the fuel filter and fuel pump and this would be good diagnostic tool. Does anyone have any recommendations? With all the vibrations, definitely steering towards a fluid filled gauge. Anyone know what pressure ranges we're dealing with with regard to idle and WOT pressures.
I did come across a gauge in the TM's with NSN: 6620-00-671-4509. However, I am unsure if this is just a temporary diagnostic type gauge or something for consistent mounted use.

 

[m38inmaine]

Manual says 45-70 psi @1800 rpm.

 

[wsucougarx]

Just had a memory flashback about my fuel issue. I remember when I first got her, there was fuel on the inside of the tub. Note I've gotten to know this Goat and the 353. The fuel was dripping from what I now know is the fuel pump. Thanks Tom, after reading your response again today, I remembered this.

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[m38inmaine]

The fuel pump has drain holes in the bottom, the manual makes mention of this and stated if fuel is leaking from them the seals have perished. Just like a weep hole in the bottom of a water pump dripping indicating a seal has gone bad.

 

[wsucougarx]

Thank you sir! I need to get reading

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