I had a similar problem with some worn out bellows on my Roland, desk top, CNC mill, They had gone stiff and didn't want to stay in place.
As usual the problem was, what to search for in ebay?
Eventually I searched for Accordion bellows, then clicked Business, Office, Industrial to get rid of the accordions. Bingo. China gets £10 of my hard earned and I get 1.5m extended 