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My NUTMATX crapped out today

MS19087

Well Known Member
Been working great for the last year. Today it squeezed and would not release. Had to disconnect air line for it to release. Then if I connected airline again it would squeeze with out stepping on foot switch. When foot switch is depressed I can hear intensifier compressing but plunger doesn’t retract. I bled system thinking there may be an air lock. No change.

Any suggestions? Thanks
 
I think the actuator is more likely the problem than the intensifier. Pressure is getting to the intensifier but not releasing prob due to the air actuator not going to the vented position when you take your foot off the pedal. Not sure how you would troubleshoot the actuator. My usual technique is to take it apart and see how it works. Might be a rolled oring. I’m sure someone will come behind me with a better thought.
 
compression pin to yoke guide hole interface

Also, check the compression pin to yoke guide hole interface. Have you been lubricating on a regular basis with white lithium grease or similar? Check for any galling between the steel parts if they were run dry very long. Check for any burr on the compression pin or yoke hole. The return force is only a hundred pounds force or so, whereas the hydraulic force driving the pin out is up to 3K.

Another cautionary note: The yoke holes are reamed a thou or so larger by the manufacturers, over the .375 diameter pin, and in my experience over time the mfg might not change out the reamer and thus the holes can get very close clearance to the pin diameter. There still could be an issue with the unit, I'm just pointing out other factors maybe not considered.

JDA makes a good point. Adequate lubrication, on the order of 6-8 drops per several hours of continuous use, should be added to the intensifier. Otherwise, the o-ring in the intensifier can get dry and grabby, and start to deteriorate.
 
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JDA makes a good point. Adequate lubrication, on the order of 6-8 drops per several hours of continuous use, should be added to the intensifier. Otherwise, the o-ring in the intensifier can get dry and grabby, and start to deteriorate.

Do you just add oil to the air inlets, or does this require dissassembly?
 
Oil Added

You can add oil drops to the pressure port just prior to the footvalve. This way it lubricates both sides of the air piston of the pressure intensifier.
 
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