Die grinder trouble

[Quinn McCarthy]

I bought a die grinder a week ago to grind something that I couldn't do with the regular grinder. Tonight it stopped spinning. I can hear the air going through it but no movement. I have been religious about oiling except for tonight.

What could be making this happen.

Thanks

Quinn

[Jim Heffner]

Sounds like the gasket or o- ring has gone bad, and allowing the air to go straight thru the tool not into the rotary vane that turns the tool shaft.

[Brendan Plavis]

That very well could be.... If it doesnt contain any electrical parts(someone please confirm, I didnt think air tools have any juice going through them) then dip it in Soapy Water.... then apply the air, and if you get any bubbling, you know its an O Ring or something like that... But please do not try this until someone else confirms... I dont want you to ruin your Die Grinder if I am wrong.....:o

[Paul Atkins]

An internal failure won't show up in soapy water. I have one that is about worn out and it still goes if I give it a 'push'. Never torn one apart, but willing when this goes. I've rebuilt air nailers and junk get in them and keeps little balls and valves from moving right, so a teardown and cleaning might do it.

[david brum]

A die grinder also won't spin if it isn't getting sufficient air from the compressor.

[Jay Allen]

I probably has one of the blades of the vane "stuck", just put a few drops of oil in it and blow it through. Hold a rag or paper towel around the exhaust when you do this though, it may push the oil out there.
All it takes is the slightest amount of water in your air lines and the vanes "flash rust".
Also, if this is a 90 degree grinder, the ring and pinion can lock-up from foreign particles between them.

[Chris Parks]

As Jay said, try lubrication. It needs to be either a dedicated air tool oil or something very thin like ATF or oil mixed with kerosine will do in an emergency. Two or three small drops before the first use every day will keep things going round and keep the air as dry as possible. Over oiling will lead to oil coming out the exhaust which is always messy.