Millermatic 135 - Shielding gas not working

rustinpeace817 · Mon Aug 10, 2020 1:34 am

Hey fellas,

New guy here. I was wondering if you guys give me some advice on fixing my welder. I have an old Millermatic 135 that's been good to me for a few years. Only has it been acting up and given my horrible porous welds.

So the issue is with the gas. I've been having to crank up the CFH's to almost max just to get semi-decent welds and a lot of times not even consistent. At 25 CFM, I have nothing coming ojt of the stinger. No hiss or anything. When I turn it up really I do get the hiss, but it doesnt last long.

The bottle is new. I swapped out the regulator and hose thinking that was were my leak was, but no luck. The tip and nozzle is clean and the orings on the end of the stinger that seats into the machine looks pretty good still. Kinda left scratching my head and I don't want to keep on guessing and buying stuff that isn't going to help.

Do you guys have any suggestions? Thanks.

cj737 · Mon Aug 10, 2020 7:08 am

Open the machine cover and inspect the fitting for the gas. You could have a loose connection or a split hose internally. Could also be time to replace the liner. Worst case, the solenoid could be bad that triggers the gas valve from the gun. Any chance you could borrow another gun or attach yours to a similar machine? I had an SSC pedal that got damaged and exhibited similar behavior (control wire was damaged).

BillE.Dee · Mon Aug 10, 2020 2:48 pm

Hi Rusti.... disconnect the hose at the back of the machine and make sure you're getting free flow at least to the machine, the, as cj stated,,,open the machine so you can "inspect" the hose connection at the drive and make sure it is properly inserted with good o rings and you don't have a broken connection at the gun. You should be able to hear the solenoid snapping open and closed with the squeeze and release of the trigger. Take the cable out of the machine and see if you can make gas come to the drive area. That will tell you which area the problem lies...machine or cable. Also, a bit of soapy water at the connections will tell you if there is a leak. OR it may be time for a new liner or cable. We don't know how much time you have on the machine. Keep us posted, please.
gramps

rustinpeace817 · Mon Aug 10, 2020 9:10 pm

Thanks for the replies, guys. Great advice.

So I took your advice and opened up the machine. I unhooked the clear hose coming out from solenoid and made sure it was working and giving off good pressure which it was. Moving onto the stinger I did notice the o-rings where kinda flattened. As I pry them out i noticed a bunch of little cracks all around one of the rings. I'm pretty sure that's where my leak would be. Going to pick up some new rings and go from there. The liner was replaced about a year ago when I accidentally pinched it. I can replace it again if needed. I'll keep you guys posted.

Thanks again!

G-ManBart · Wed Aug 12, 2020 3:21 pm

rustinpeace817 wrote:Thanks for the replies, guys. Great advice.

So I took your advice and opened up the machine. I unhooked the clear hose coming out from solenoid and made sure it was working and giving off good pressure which it was. Moving onto the stinger I did notice the o-rings where kinda flattened. As I pry them out i noticed a bunch of little cracks all around one of the rings. I'm pretty sure that's where my leak would be. Going to pick up some new rings and go from there. The liner was replaced about a year ago when I accidentally pinched it. I can replace it again if needed. I'll keep you guys posted.

Thanks again!

If the liner is only a year old it probably doesn't need to be replaced. Blow it out with compressed air and it should be fine. If you really want to go the extra mile you can soak it in acetone for a while before hitting it with compressed air.