An undercarriage system for a track-type machine includes an idler height adjustment system having piston assemblies supported in a frame, in opposition to one another, to contact upper and lower sides of an idler support element or block. A conduit connects the piston assemblies and has therein a fluid exchange valve adjustable to an open position where a flowable material such as grease is exchanged through the conduit between the piston assemblies, and a closed position where fluid connection between the piston assemblies is blocked and idler height is fixed.