LEGO 5104 Pneumatic Piston Cylinder 48 mm Yellow is a vintage Service Packs set from 1987 valued at $15 for new and sealed sets, up 656% from an original retail price of $1.99. Annual appreciation has averaged 4.59% since release. On the used market, values range from $8 to $11 based on condition.
LEGO 5104-1 Pneumatic Piston Cylinder 48 mm Yellow is a Service Packs Technic set released in 1987, containing 1 piece. The pack includes a yellow 48 mm pneumatic cylinder with a single medium inlet, used to create actuated functions in Technic builds. Sold as a replacement part, it supported maintenance and expansion of LEGO Technic pneumatic models of the period.
A new and sealed Pneumatic Piston Cylinder 48 mm Yellow is currently valued at around $15, with annual growth of 3.1% that is expected to level off to around 2.4% in the coming year. The average used price is $9 for those in good overall condition. New and sealed listings currently range from $13 to $16. Recent market trends show a period of price correction, with values declining over the past year.