cg-550/030/a/gt/hp maintenance & operating instructions - Field ...

SERVICE GUIDEPROBLEM PROBABLE CAUSE SOLUTIONPumps water O.K., willnot pump grout.Grout mix too "thick", doesnot enter pump chamberAggregate too large,preventsball from seating.Aggregate segregations inDischarge hose. (“SandPlugs”)Add water to grout mix, butbe careful not to dilute mix soMuch as to cause aggregateto segregate.Change to smalleraggregate, or screen outlarger particles.Drain residual water fromDischarge hose prior topumping grout.Aggregate improperlygraded;change aggregate.Pump stalls on dischargestroke.Pump runs but does notdischarge.Piston will not reversedirectionPump strokes unevenlyor too slowly.Grout material hasexcessive Coefficient ofinternal friction.Pump discharge or hoseplugged with grout.Grout not entering pumpChamber.Directional valve spool“stuck”Misadjusted shuttle valve.Some premixed groutmaterials are not pumpable.See section on grout mixrecommendations.Disconnect discharge hose,check pump, clean out hose.Grout too "thick" orobstruction in hopper.Shift spool manually withsmall diameter object, suchas a nail or awl.Readjust shuttle valveadjusting screws (13); turnout to increase speed and into decrease speed.®