Erattic behaviour from da air sander

[julianf]

I have a mirka air sander.

It's behaviour is erratic. Sometimes it works fine for ages. But other times it works, then slows right down, speeds up again. Sometimes I push the trigger and it won't even spin.

This seems entire independent of air supply. And, yes, I put some oil down the air inlet before every use.

It requires a special tool (that I don't have) to open it up.

Does the behaviour sound familiar to anyone?

Thank you

 

[123hotchef]

my die grinder did that too i put it down to cheap carp

 

[RWD3M]

Hmm.. this is a bit of a long shot but I had similar symptoms on my Craftsman D/A and eventually discovered that it had it's own air control valve that had worked a little loose and was restricting, quite randomly, the airflow. Tightened up and adjusted, now works perfectly.

Good luck.

 

[123hotchef]

someone told me to put a shot of derv through the air intake to clean it out that worked on my ratchet for a while

 

[postie jon]

probably dust and oil combined into a paste inside , good strip down and wash with degreaser ,will prob cure it , our old sanders were allways clogged up.

 

[Craig-SM]

^ this

 

[8ob]

Dont know about the da but nut guns can freeze , give them a few minutes and they are away again. Probably down to a tad of moisture in the system but we do get this.

Bob

 

[julianf]

probably dust and oil combined into a paste inside , good strip down and wash with degreaser ,will prob cure it , our old sanders were allways clogged up.

This is kind of what I suspect. But as I say I can't even get I to it at present.

I'll have another look and see if I can't make the required tool, as I suspect it costs about as much new as I paid for the sander : /

I purchased a 1/2 gun from the boot sale once. Stripped that, freed the vanes, and it's been fine ever since. But that one just did not work at all. This one works spot on one day and is an **** another.

 

[slim_boy_fat]

Would a run through an ultrasonic cleaner do the job without dismantling - or perhaps it wouldn't like total immersion?

 

[fizzy]

Would a run through an ultrasonic cleaner do the job without dismantling - or perhaps it wouldn't like total immersion?

Perhaps total immersion in Kero? Leave it soak for a while. Could cause O rings to swell though.

 

[brightspark]

just shot a load of wd40 through it and run it on high pressure the vanes might be gummed up or the bearings it has worked on a couple I got cheap

 

[Daz2012]

I just stripped one down.....not a Mirka...
because of similar symptoms to yours.
Cleaned it out and oiled it,put it back together,nothing, wouldn't work at all.
Took it apart again,cleaned it out,WD40'd it and now it works great.
So on that basis I'd suggest WD40 rather than oil

 

[Hitch]

I tend to flush air tools through with a good dose of SAS spray when they start playing up. (similar to wd40). Run it few seconds, repeat a few times. Then a bit of slightly thicker air tool oil to run it on.

 

[julianf]

Ive pretty much filled this one with penetrating oil.

This one is a different colour to mine, but im sure its the same -

Its irritating, as, first i need that thin bicycle spanner thing - which i dont have. Then the custom tool to unscrew it - which i dont have. Then a puller - which i can probably bodge, but even still...


I think my 1/2" ratchet needs an allen key.

 

[Daz2012]

All the DAs I've ever owned have used a single circlip to hold the bearing in.
That looks complicated for complications sake