RobCox
Member
- Messages
- 516
- Location
- Cambridge, UK
Here's hoping someone out there might have some bright ideas...
I've been asked to sort out a Bosch gsh5ce demolition hammer for a chap who I've done a fair number of random jobs for in the past. He's the chap who drives the Terex that was used to lift my old lathe out and new to me lathe into the workshop, which he did as a favour. Therefore I'm kind of obliged to help him, even with my sum total of zero knowledge of these.
I was told that it doesn't always hammer. He just wants it to work. Note it's some sort of intermittent fault. The worst kind.
So, off to google, followed by watching a video by Dean Doherty showing how to strip one down and reassemble. I ordered a wear and tear repair kit from Bosch, then stripped it down for a clean. These are the various bits after disassembly:
I washed all the top assembly bits in white spirit so it would go back together clean. At this point, I noticed that it had been "serviced" before, this chipped lip that retains a clip being an example of the delicate way it had been previously handled:
Other delights I found were a missing pin so I had to order kit #854 from Bosch, along with clip #18 (missing when dismantled). This is the drawing off the website so you know what on earth I'm on about:
I firstly changed the brushes, as new ones were supplied in the repair kit, although the old ones weren't too bad, but were about 3-4mm shorter. The motor checked out fine.
I then rebuilt the piston assembly using EP2 grease, (not the Bosch grease as that was a hefty £35 for 225ml!) and reassembled everything putting all the seals and spacers in the right place this time (!). I made sure there was plenty of grease on everything without packing it in, got it back together and tried it out.
It started hammering fine. Then, with it running I backed off the pressure at which point it wouldn't hammer with pressure applied, motor running fine. I pulled the off switch, and as it slowed it started hammering! Turn it on again, hammers fine again. With pressure continually applied it works no problem, digging the tool spike into a concrete victim till it stuck. But, back off the pressure and it's like something somewhere gets stuck somewhere and no amount of downward pressure will get it to hammer. Turn off, and with the last few revs of the motor it hammers again
.
So, clearly, I haven't fixed it. Does anyone have any idea what might be going on? Google is about as much use here as an ashtray on a motorbike. I'm going to have to strip it down again, but it'd be nice if I knew what I was looking for.
I've been asked to sort out a Bosch gsh5ce demolition hammer for a chap who I've done a fair number of random jobs for in the past. He's the chap who drives the Terex that was used to lift my old lathe out and new to me lathe into the workshop, which he did as a favour. Therefore I'm kind of obliged to help him, even with my sum total of zero knowledge of these.
I was told that it doesn't always hammer. He just wants it to work. Note it's some sort of intermittent fault. The worst kind.
So, off to google, followed by watching a video by Dean Doherty showing how to strip one down and reassemble. I ordered a wear and tear repair kit from Bosch, then stripped it down for a clean. These are the various bits after disassembly:
I washed all the top assembly bits in white spirit so it would go back together clean. At this point, I noticed that it had been "serviced" before, this chipped lip that retains a clip being an example of the delicate way it had been previously handled:
Other delights I found were a missing pin so I had to order kit #854 from Bosch, along with clip #18 (missing when dismantled). This is the drawing off the website so you know what on earth I'm on about:
I firstly changed the brushes, as new ones were supplied in the repair kit, although the old ones weren't too bad, but were about 3-4mm shorter. The motor checked out fine.
I then rebuilt the piston assembly using EP2 grease, (not the Bosch grease as that was a hefty £35 for 225ml!) and reassembled everything putting all the seals and spacers in the right place this time (!). I made sure there was plenty of grease on everything without packing it in, got it back together and tried it out.
It started hammering fine. Then, with it running I backed off the pressure at which point it wouldn't hammer with pressure applied, motor running fine. I pulled the off switch, and as it slowed it started hammering! Turn it on again, hammers fine again. With pressure continually applied it works no problem, digging the tool spike into a concrete victim till it stuck. But, back off the pressure and it's like something somewhere gets stuck somewhere and no amount of downward pressure will get it to hammer. Turn off, and with the last few revs of the motor it hammers again
.So, clearly, I haven't fixed it. Does anyone have any idea what might be going on? Google is about as much use here as an ashtray on a motorbike. I'm going to have to strip it down again, but it'd be nice if I knew what I was looking for.
