Ok. Then i will place everything here :
Problem manifested by the fact that the pump does not create a pressure.
It looks as if pumped air escapes through a deflate hole.
Inside aluminium pipe is second inner ( smaller plastic ) pipe.
The main problem is pelled away upper side of this smaller plastic pipe.
If the glue is pell off then this smaller pipe goes deeper ( goes up ) into aluminium pipe (ca. 0,5 cm ) up to mechanically stop.
If this happens then lower end of plastic pipe is too short and connection isn't tight and air is moving between aluminium and plastic pipe.
During the production or design something went wrong :
a ) inner plastic pipe is too srhort ca. 0.5 cm
or
b ) thread on the aluminium tube is too short ( or aluminum pipe is too long )
To repair it :
1. extract the piston from tube
2. Take it and hold with legs like on picture DSC_0364
3. use rag to unscrew the piston ( need to force becouse it's glued ) ( DSC_0361 )
If inner pipe is at the same level or deeper than outer aluminium pipe then we can be sure that we found this problem.
4. Take pliers and cearfully pull out this inner pipe. DSC_0363.
5. Take the metal saw and cut off 0,5 cm thread from aluminium pipe, and 0,5 cm from plastic piston DSC_0362
6. Get some glue and smear internal side of plastic pipe at both ends.
7. Get plastic pipe ( side without flattening ) and push it into aluminium pipe to the end.
8. Get some glue and smear thread of aluminium pipe.
9. Tighten the piston to the end on the aluminium pipe in the same way like in point 2. 3. ( it should go deeper than originally )
10. Leave it until glue harden
11. Assembly it back and enjoy.