I have a Porter-Cable, model 340, 1/4 sheet palm sander and it hasn’t been working very well. I thought it was the brushes and that I could take it apart and replace them. After all is said and done, how do I get the case apart? Is there and internal catch or something? It is a pretty old unit but still, I would like to be able to repair it now that it is sort of apart.
The brushes have slipped inside and a few of the spacer washers plus an ‘o’ rig have slipped. I need to get the case apart so I can get it all back together. Help.
Cheers, Rundle
Replies
Rundle,
On one side of that model you will see that there are five holes, each about 1/4" in diameter, molded into the housing. Four of the holes are in the main body, one is in the dust collector port extension. At the bottom of the holes, they're an inch or so deep, are the screws that hold the two halves of the sander's outer casing together. The screws quite possibly have Torx heads, or they may be Phillips headed. If you remove the screws, the two halves of the housing will separate giving you access to the brushes.
John White
Thanks John. I have all those screws out plus a few more. Should the sides simply slide apart or is there a catch somewhere inside. My unit seems to have something catching around the bottom bearing plate for the motor and it will not come apart. I am worried I will break the case if I force it.
Worst case scenario, I guess, is I take it to a shop.
Cheers,
Rundle
With most tools like this once the screws are out, the two halves come apart easily.
I would tap and pry gently, I suspect that the parts are just stuck together. The bearings and possibly some of the gear train parts are a press fit into both halves of the housing and they act like biscuits in two boards holding the two sides together by friction. Dried out lubricant and dust can make the bearings hard to free up from the plastic housing. Getting a bit of penetrating oil or even just some paint thinner into the bearing area might free things up.
John W.
P.S. I just found a parts sheet for your sander. The sanding pad is held on by four Torx screws, remove them and the pad, which will give you some access to the bottom half of the tool. The round dust housing that surrounds the pad is held onto the two part upper housing by ten screws. You probably need to remove those screws, and the round housing, before the two halves will separate.
Edited 12/19/2007 5:38 pm ET by JohnWW
Edited 12/19/2007 5:49 pm ET by JohnWW
Edited 12/19/2007 5:51 pm ET by JohnWW
Thanks very much for the information. Is there any chance you can forward that parts sheet? I haven't been able to find my original owners manual.
Sorry I am so long in replying but I had some computer problems and was travelling over the Christmas holidays.
Thanks again for all your help.
Cheers,
Rundle
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