GA-20C Gun Repair

[Drf255]

My MM200 was purchased for a great price but has a few expected problems.

It arcs and feeds wire well.

The GA-20C gun has both inner and outer hose tears by the input area. Can this gun be repaired, or does it need replacement? If it needs replacement, which guns are compatible with my machine? I see Bernard guns on eBay going for reasonable prices.

Here are some pics and many thanks in advance.

[duaneb55]

Common issue with the older GA-20C gun. Had the same problem with mine a few years ago and after cutting back about 2' and still had bad gas hose I retired it. Had another good one given to me and am still running it on the MM200 but have a Bernard Q-300 on my suitcase feeder. If the current GA-20C takes a dive like the original, it'll be replaced by a Bernard.

[ccawgc]

Go to miller's web site and down load the owner's manual for the gun. It should include a parts manual. From this you may still be able to order repair parts. You can always to a field fix. Two sticks and duck tape. This will allow you to use the welder until you buy a new gun. Any brand gun with a miller power pin and trigger plug will work. Your choice.

[Drf255]

So any Miller compatible MIG gun will fit my old machine? This is what I wasn't sure of.

The sad part is that the rest of the gun is in pretty good shape.

[shovelon]

Mine has been breaking down for years, so I put on a hook to support it.

The only real problem with my GA-20C is a broken off trigger, you know the blue part. If I could get that I would not have to reach in a bit to start the arc.

I know I will have to get a new one but I just love the old one.

[ccawgc]

any miggun with a standard miller power pin will work, Miller, tweco, Bernard, and ect.
Just make sure it is rated the same. Miller recommends the new m-150 as a replacement.
The GA-20C is a 150 amp gun.
Just checked and the plastic locking ring (049 312) is not available from miller any more. They still have the rubber strain relief in stock. (088 122)

[Drf255]

I cut back the strain relief, opened the input handle and slid it back up into it. I used the ghetto black electric tape method to secure it. Looks fine now. A little armor all on the feed tube and Voila, looks great.

My handle assembly is missing the Allen screw that secures the gooseneck to the plastic handle. It does have the liner retaining screw.

This screw is $2.27 on Miller4less.com.

It's listed as .500-13 x .375 in the owners manual. I don't understand this designation.

If I go to the hardware store for this screw, what would I ask for? It clearly does not look like it is .5 or .375 in any dimension. I would imagine the 13 is thread per inch?

[Drf255]

Also, when I looks for nozzles and tips for this gun, what "series" do I consider it? I need/want to buy some tips and nozzles. Are they interchangeable with any newer gun parts?

[boatbuoy]

If I go to the hardware store for this screw, what would I ask for? It clearly does not look like it is .5 or .375 in any dimension. I would imagine the 13 is thread per inch?[/quote]

that's a 1/2-13 by 3/8 lg set screw.get it at the local hardware store.

[Drf255]

Now that I made the "repair", wire won't feed through the liner. It fed through it before this. The area of the obstruction is within the input fitting I had to open.

What could have happened? All I can think of is that the liner kinked when I took those photos.

[Drf255]

Issue resolved!

[duaneb55]

Care to share the resolution for the benefit of any others that may find themselves with the same issue?

[Drf255]

Unfortunately, from being a moron and leaving residual wire in the gun from when I just bought the unit and before repairing the gun. I started taking it apart and realized what had happened when I took the tip off.

[duaneb55]

Well welcome to the "brain fart" club.