how to check for correct damping

[silas]

I have an old pair of kyb shocks model 634 over 62100 41110, after taking the spring off to check the shocks I noticed that the damping only occurs on the last 3cm or so of shock compression. Is this normal? Never had one apart before. Any advice would be appreciated.
thanks.

[Nathan S]

That's not right. Suggests air in the shock, where oil should be.

If they're old style emulsion shocks (ie: not gas pressurised) try turning them up the right way and pumping them through a couple of dozen times. If they don't come good, then the oil has escaped.

If they're gas pressurised, then they need a rebuild. Either the oil has escaped, or the gas/oil separator piston/bladder has failed.

[JohnnyO]

Sounds like it's lost most of it's oil, it should have damping for the whole stroke in the inverted position. Not sure if it's a gas pressurized model as losing it's pressure can also affect damping in the first part of the stroke.

[John Orchard]

Send it to RAD, they'll fix it for not much $'s

[oldfart]

shocks are to suit  Rm 250/370 A.... from part # supplied .
When you push the shaft down does it come up by its self  ??.... Some of the early models you had to compress the shaft an turn it and hear for the clicks to adjust it's dampening

[silas]

they are rm 250a oil filled shocks , the shaft slides freely till the last few cm's of compression then it is quite firm, they do return to the point that the resistance begins, on their own.
trying to determine if i should spend the time to clean these shocks up and use them.
are these particular shocks serviceable? they have no gas reservoir.

thanks for the input.

[crs-and-rms]

the c models had the turn shaft to adjust the dampening