HELP with Fx 4 stage pump disassembly!

[Menttaliist]

Hey.

I'm seriously needing some help with this hand pump disassembly and could't find any helpful info on the web.

I attach some pictures but basically i'm stuck in here and can't go any further.

The head of the outer piston (where the handle goes attached to) is not moving and acording to the schematics there's not any threads in there, as you can see I've even clamped it down with a wrench in order to have more grip but it's not working either.

Help would really be appreciated since I'm stuck in here since a few months back and need to change some orings

Cheers

 

[Kevin23]

My other branded pump has that part held by a pin

 

[Menttaliist]

This is not the case. And I'm not sure that's the part I've got to remove in order to continue disassembling the pump either, just guessing

 

[Helmet]

Try to heat up the black anodized part, maybe it will lose grip easier.

From 0:55 you can see how it is put together. ->



https://www.youtube.com/watch?v=uabGfOKS79s

 

[Menttaliist]

We are going places now Helmet!

Thank you very much, +1 to you

I used the heat gun and it's now off.

I guess now I've got to heat up the brass part to screw it off right? (See picture below)

 

[Helmet]

Yes probably. I haven't disassembled any FX pumps yet, but a lot of other brands, and the threads internally are always locked with liquid tread lock. Heating is the way for disassembly. Remember to use thread lock when you reassemble the parts, or the parts will unscrew them self over time.

 

[Menttaliist]

I was worried about the possibility of melting internal orings when heating.

And how do you grab the shaft in order to apply force to the threads once heated up? Because the surface is quite slippery.

I'm trying as shown on previous pictures with some self grip locking pliers and a piece of leather but still sliding.

Thanks

 

[Helmet]

Sorry for the late reply. I guess you have to apply more heat. Most tread locks will need around 150 degrees C to loosen up. If you do not have any special tools for the job, then leather patches and self grip pliers are what you need to use. Unfortunately, the possibility of damaging o-rings is a factor when disassembling parts that are fastened with Locktite. But apply some torque to the parts when heating them up, and you will feel when the thread lock is starting to slip, so you don't heat the parts up more than necessary. This way the o-rings probably will survive.

 

[Menttaliist]

Thanks a lot. I'll be trying this evening then.

Regards,

Manuel

 

[Menttaliist]

I was finally able to unscrew it with the help of a vice and even more heat as you suggested.And once again I'm stuck haha.

The top piece shown on the beggining of the video you addressed is extremly tight in there. Any ideas to remove it?

This whole procces is much more difficult than i thought

 

[Helmet]

As I said in my first reply, I have not disassembled a FX 4 stage pump so far, so I'm not familiar with those pumps. But the part you want to remove seems to be made of aluminium, and since it is stuck inside a steel tube I would put it in a deep freezer for a couple of hours. Aluminium have a much greater thermal expansion than steel, so if you cool the parts down, the aluminium will shrink more than the steel tube. Give it a try. You might also have to fasten the top part in a vice (between two pieces of wood to prevent damage to the part) and try to pry it loose by pulling the tube.