The hammer suddenly stopped and wont restart. No warning, no motor fluctuation. Is it likely to need new bushes? Had only been using it on floor tiles for less than 2 minutes. Now nothing. Depress the switch and nothing happens.

1= 80% Piston ring worn out (o-ring)replace new o-ring
2= 20% piece ram or striker stuck in the cylinder.Just clean up

Try motor rebuilding/repair shops or ebay for brushes.

You need to clean it and oil the bushings. When this doesn't solve the problem, change the start capacitor. If it continues to hum or make noise, replace the bushings. A repair technician may be helpful.

Not without trying to narrow down the choices.
If it shuts off like you turned the key its probably something electrical like a relay or the coil.
But you would really need to troubleshoot it when it happens to narrow it down.

make sure the motor is getting a good ground otherwise wak that ****** with a hammer,it may have just jambed up so check all moving wiper arms and rods from motor to wipers. If you have power to motor then it can only be motor or linkages

First, always use a seperate 12 volt power pack and NOT the internal batteries. Do a Calibrate Motors -- first thing whenever you turn on the telescope.

I wouldn't replace this bushing unless it's obviously worn out. I know of this recommended method when a puller is not available, pack the bearing bore with grease and use a socket and extension or similar rod that fits snug as possible in the bearing bore and hit this tool with a hammer as to use a hydraulic effect. the pressure of the grease will push the bearing out. This method is used on, rear wheel driven, flywheel bushing removal. Good luck!

You can get new bushings from a parts store. I always recomend NAPA. Remove the nuts that hold the bushings in and using a hammer and chisel or a hammer gun knock them out. The back bushings are much more difficult than the fronts. If you are fairly mechanically inclined you could do it. Once the old bushings are out you need to knock the new ones in and put the nuts back on.

replace the regulator.
There are no bushings.

Drive it home with a ball peen hammer.Just a note here,behind every leaking seal is a worn out bushing,so don't be surprised if replacing the seal doesn't stop the leak.Inside the tailshaft housing is a bushing that engages the driveshaft yoke.It should be a fairly tight fit when the yoke is installed and the driveshaft is bolted up.Grasp the driveshaft and yoke and wiggle it up and down,should be just a couple thousandths play.If excessive play,it needs a new bushing which entales removing the extension housing,driving out old bushing,and driving in new bushing which requires bushing drivers.But the seal,you just drive it in with a hammer.It will want to walk the opposite direction,so you have to press it down with your other hand while hitting it with the hammer.Also make sure the seal has some lube on it where it contacts the yoke.A dry seal will rip and leak.