battery drill maintenance

So come on then hands up, how many of you actually do it, maintenance of course on your power tools,  what did you think I meant. lol.

I usually do mine every two years, this time around I have been a force to do mine early as one of my cordless the drill has developed  a start-stop intermittent problem  bloody annoying, it always seems to happen just when you get the drill lined up to drill a hole press the trigger and nothing Gr.

While I sort the start-stop problem out I may as well service both my other cordless drill at the same time. I like to keep them checked over to get the best from them. Quality battery drills are now very very expensive items to buy, the spare part is not cheap either.

I have three  Bosch battery drill two of these are hammer drill as well as being drill drivers, one being the 14,4v the other 12v  drill driver. I have one  Makita drill driver 7.2v  which goes right back to 1988  and is still in perfect  working order, I still have the original battery as well, still charging although it is getting lazy.



My other Bosch is a 12 v hammer drill  which I'm not going to service this time around I have not included it in the photo, I'm going to sell that one on, I also have a Hitachi SBS electric hammer drill so don't really need three hammer drill any more. Here are the three I'm going to service.

On the right is the 14,4v hammer it's quite a heavy drill to use this is the one with the start-stop problem, In the middle to be serviced is the 12v drill driver lovely comfortable drill to use. On the left, the first battery drill I bought an excellent drill is my trusty old Makita 7.2v I semi-retired it a few years ago and only bring it out when I need several drills sets up all at any one time. I used this one today as I had to get into a tight spot, ooh I had forgotten just how much torque this little guy really has for such a small low the powered drill did the job a treat.

Here's the 14,4v drill stripped apart, as soon as I opened it up it was obvious what was causing the stop-start problem. I searched Bosch's web site for new parts which are available at £31.00, then I searched e-bay and found 1 at £7.50,  I do like a bargain.



As can be seen here a lot of damage and corrosion to the  contact connection arms inside the handle, it appears at some time in the past one side has been bent and each time a battery was removed for charging and then  replaced with another, it has slowly rolled the end of the connections arm inwards until it never made contact with the battery terminals at all, or it was just slightly touching the terminals causing the stop-start problem I was experiencing.

New switch how it should look.



Next was to solder the new switch to the wiring which only takes a few moments. On the right, the switch reassembles back into the handle with the trigger forward/ reverse mechanism set up as well.



While I have it stripped down  I think it would be a good time to remove the brushes and replace them.



I have some special grease somewhere I used in the past,  just a few small spots here and there just to keep the gearing and bearings lubricated. Hmm now, where did I store it away to? enjoy.