how to dismantle Bosch drill (CSB700 2RE)

foy9999 · Post by **foy9999** » Sun May 30, 2021 1:16 am

Hi folks

I've had this drill since 1988 and never had any problems with it until now...

Sparking from brushes and it's now stopped working. New brushes didn't fix it.

I think the armature needs cleaned (part the brushes run on) but can't get to it.

I've removed the handle (exposes switch and brushes) and the front part (chuck, front body and gears) but can't figure out how to remove the (black) centre section from the main body to expose the armature :dunno:

I've not missed any screws but the thumb-switch on top of the drill (which changes from drill to hammer-action) seems to be the problem. It turns a shaft which goes down into the bit I want to remove.

It won't pull up and out but I noticed there is a (4mm) roll-pin sitting in the body just off-centre to the shaft.

Am think if you drift the pin inwards (God knows where it will go) the shaft will pull out and the body will come apart.

Any thoughts on this?

this switch seems to prevent drill coming apart

looks like roll-pin holds shaft of switch into drill

Neelix · Post by **Neelix** » Sun May 30, 2021 1:09 pm

Look on YouTube

foy9999 · Post by **foy9999** » Tue Jun 01, 2021 10:33 am

Neelix wrote: ↑Sun May 30, 2021 1:09 pm Look on YouTube

can you give me a link to this specific issue

foy9999 · Post by **foy9999** » Tue Jun 01, 2021 10:43 am

Ok so I found the parts list and it showed the size of the roll-pin (4mm x 30mm). I .'. used a 4mm drill-bit to drive it out (had prev been using a 5mm). Got the shaft out but there was no improvement so the thumb-switch/shaft is nothing to do with separating the halves.

I try never to lever components apart as 99% of time this leads to breaking something but there was no other option here.

Gentle levering with screwdriver then tyre-levers got it apart and no small pieces flying out

I quickly found out that the small bearing on end or armature shaft is seized. Looks like it has melted some sort of tape or insulating material.

Not got old bearing off yet despite footering about with a 2-legged puller on it for about an hour. I can never get these things to work. I think it'll be easier to slice it off.

Strangely for a German product it has an English bearing.

Will also need to see if the 'tape' features in the parts list. Must be there for a reason

roll-pin driven out allowed shaft to be removed but had no effect regarding separating body

something has went wrong here

bearing will be easy to source

need to get old one off first

Dave54 · Post by **Dave54** » Tue Jun 01, 2021 11:25 am

Looks to me more like the bearing has been rotating in the plastic case, and has melted that. If it's that then it needs a new case,
Commutator looks pretty well shot, it needs skimming at the very least, if there's enough metal there to do so.
Really excessive sparking is usually caused by the armature windings being shot, or occasionally the field coils.
I wish you well with it. I've got the same drill (pretty sure) from around the same time, and it's been good.
However unless you have spare parts available, or a spare drill to cannibalise, my experience with power tools is generally to just replace them.

fin · Post by **fin** » Tue Jun 01, 2021 5:28 pm

looks as though thats one of those times when its too much graft and money to get the thing back to working order.

i had a look and it seems this is a percussion type hammer drill rather than an sds drill. if ya use it for drilling masonary then sds drills are wayyyyy better at that sort of thing.

i use mine all the time as im a joiner. so ive got a dewalt battery sds. good bit of kit. i got mine at screwfix with 2 batteries for about £200

Dave54 · Post by **Dave54** » Tue Jun 01, 2021 6:10 pm

fin wrote: ↑Tue Jun 01, 2021 5:28 pm looks as though thats one of those times when its too much graft and money to get the thing back to working order.

i had a look and it seems this is a percussion type hammer drill rather than an sds drill. if ya use it for drilling masonary then sds drills are wayyyyy better at that sort of thing.

i use mine all the time as im a joiner. so ive got a dewalt battery sds. good bit of kit. i got mine at screwfix with 2 batteries for about £200

I agree with you fin. They are a percussion type, and while it's a decent enough drill, I don't think I've used my similar one to the OPs for ten years.
SDS is the tool for masonry drilling.
If I've got one or two holes to put in soft block etc. then I've got a Makita cordless percussion.

fin · Post by **fin** » Wed Jun 02, 2021 6:12 pm

aye like for example if i had to put say a 22mm hole thorugh both leafs of a house wall the sds drill absolutely flies through in comparison to an older style drill, and standard 5.5mm, 6mm or 7mm holes an sds is absolutely ideal for that. plus the bits are cheap as chips from toolstation etc

Dave54 · Post by **Dave54** » Wed Jun 02, 2021 6:58 pm

No comparison as you say. I've only got an oldish McAllister corded, but I had to put a 25mm hole through some blocks with granite pebbles in them.
Got a new bit from SF, and it ate it's way though in minutes. I've got some big long drills for the percussion from when I was house bashing, but they'd have taken an hour to get through.