Does anyone have, or know of, basic step-by-step instructions for disassembly of the FX 4 stage "turbo model" hand pump?
All I have found on the web are instructions and video for the 3 stage pump, but that is a different animal.
On the Gehmann support pages I haven't found anything for the 4 stage pump (model m100).
I have the parts diagram for the FX 4 stage pump but this doesn't give any idea of how to proceed.
I'm afraid of gouging or damaging parts trying to get them apart.
Thanks for your tips!
Disassembly of Gehmann/FX 4 stage hand pump
Moderators: pilkguns, m1963, David Levene, Spencer, Richard H
Re: Disassembly of Gehmann/FX 4 stage hand pump
You should get in touch with Nicolas, from www.targets.ca, I'm sure he'll be able to help you.
Re: Disassembly of Gehmann/FX 4 stage hand pump
I got the service kit from Cibles Targets Canada but their instructions were to use the included parts diagram and look at the videos. I did that but in the end I just had to devise my own procedure. It is not rocket-science, but getting started was not at all like the 3 stage procedure.
I had the additional frustration of nearly all of the threaded connections being really frozen. When clamping the tubes in my vise, the tube being clamped in the vise was slipping. I was concerned that if I tightened the vise any more, I would start crushing the tube. In fact, there was some slight deformation of the 18mm diameter tube. I tried differential heating (put the "female" part in a plastic bag and immerse in hot water to expand it), and also used pieces of roughened inner-tube rubber to combat the slipping. That worked. The threads had some kind of hard white residue in them.
Once disassembled, it was straightforward to clean and reassemble. The silicon beads were full of old grease which must have migrated down into the main pump body. Otherwise the only damage was on the high-pressure piston: that O-ring was in pieces.
I attach for anyone interested, my instructions for disassembly and re-assembly: they refer to the parts numbers on the FX parts diagram which I also attach. Note that this diagram is pretty up-to-date. The one received from Cibles Canada looks like an older version and it had one or two minor discrepancies.
I had the additional frustration of nearly all of the threaded connections being really frozen. When clamping the tubes in my vise, the tube being clamped in the vise was slipping. I was concerned that if I tightened the vise any more, I would start crushing the tube. In fact, there was some slight deformation of the 18mm diameter tube. I tried differential heating (put the "female" part in a plastic bag and immerse in hot water to expand it), and also used pieces of roughened inner-tube rubber to combat the slipping. That worked. The threads had some kind of hard white residue in them.
Once disassembled, it was straightforward to clean and reassemble. The silicon beads were full of old grease which must have migrated down into the main pump body. Otherwise the only damage was on the high-pressure piston: that O-ring was in pieces.
I attach for anyone interested, my instructions for disassembly and re-assembly: they refer to the parts numbers on the FX parts diagram which I also attach. Note that this diagram is pretty up-to-date. The one received from Cibles Canada looks like an older version and it had one or two minor discrepancies.
- Attachments
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- FX-handpump-turbo_parts_diagram.pdf
- (236.68 KiB) Downloaded 214 times
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- FX_turbo_pump_disassembly-re-assembly_steps.pdf
- (421.51 KiB) Downloaded 226 times