Gas filling arrangement for a telescopic suspension unit

A telescopic suspension unit comprising a cylindrical container for containing a fluid under pressure, an inner cylinder therein defining an annular chamber between the container and the inner cylinder, a rod guide closing the upper end of said inner cylinder and having a passage therethrough opening into said annular chamber, a rod extending in sliding engagement through said rod guide and extending out of the upper end of said container, a seal member normally abutting against the inner surface of the upper end of the container and in sealing and sliding engagement around said rod, said rod guide being spaced from said seal member to define a space between said seal member and said rod guide, a spring in said space and directly engaging said seal member and being supported on said rod guide for urging the seal member against the inner surface of the upper end of the container, the upper end of the container having an opening therein through which said rod extends and having a size for leaving a clearance around the periphery of said rod for allowing insertion of a pressing tool between the periphery of said rod and the edge of said opening for displacing the seal member downwardly against the force of the spring to move the seal member away from the upper end of the container to form a gas filling passage between said inner surface of the upper end of the container and the upper surface of the seal memmber, said rod guide having an upwardly and outwardly facing shoulder thereon around said rod, and a further annular seal member around said rod and abutting said shoulder for movement away from said shoulder when fluid under pressure passes along said rod through the rod guide from within said inner cylinder and for being pressed against said shoulder when fluid under pressure is in said space between said rod guide and said first-mentioned seal member.