Pickup Dump Works Off Power Steering Pump

Pickup Dump Works Off Power Steering Pump TRUCKS Modifications You can turn your pickup into a dump truck using power supplied by your truck s power steering pump Larry Richter director of the Mother Earth News Magazine s Eco-Village developed the idea and agreed to share it with FARM SHOW readers The project began a year ago when Richter bought a used 1975 Chevy 3/4-ton pickup that was no longer equipped with a bed He built his own heavy-duty dump box Critical to the success of Richter s dump-bed design is the rear hinge setup which is made from 3-in channel iron 1-in steel pipe and some cold-rolled rod Two 3 by 10-in channel iron posts boxed at the top end for extra strength are bolted and welded to the truck s chassis rails at the rear Two-inch lengths of schedule 40 pipe welded through the posts serve as bushings for the 1 by 40-in hinge pin which is locked to the bed through similar pipe mounts that are boxed and welded to the bed s main rails Once he had the home-made box hinges Richter had to figure out where to mount the hydraulic cylinders The 2 1/2-in dia cylinders with 24-in strokes have a straight load-lifting capacity of 11 780 lbs Since they re mounted at an angle however some of the capacity is lost The cylinders upper clevis eyes are locked with 3/4-in cold-rolled pins to brackets on a crossbar just forward of the bed s midway point He fastened the lower ends of the cylinders to angle iron attached to the truck chassis frame rails He chose an angle that gives him a truck tilt of about 32º although he says if he did it again 45º might be better To secure the hinged bed against any lateral shifting he made up two descent guides of 2 by 15-in channel iron sprayed one end of each slightly and faced the flanges with 3/16 by 2-in flat stock These guides fasten to the chassis about a foot behind the rear of the cab so that the bed s main rails settle snugly between the guides when lowered The most attractive feature of Richter s dump-bed conversion is the fact that it s relatively inexpensive due to the fact that it uses the power-steering pump for power In essence instead of supplying high-pressure fluid directly to the steering box the converted pump now delivers its load through a pressure guage and into a 4-way hydraulic control valve The only modification necessary was to replace the existing reverse-flared hose fitting with a standard pipe-thread coupling From there one of the valve s working ports is plumbed to a splitter ù simply a glorified T fitting - the two outlets of which are connected to the lower chambers of the hydraulic cylinders The upper chambers of the double-acting cylinders are likewise joined through a T-fitting and plumbed to the control valve s other working port To complete the fluid circuit the valve s outlet port is tied back into the steering box through a reverse-flared fitting and the box is plumbed to the pump return port in the standard fashion Of course as he would with any hydraulic circuit Richter was careful that all the lines and both sides of the cylinders were filled with fluid to assure that no air pockets were trapped in the system before he made the final connections Under normal driving conditions with the bed down the three-position 4-way valve s open-center designs allows pressurized fluid to bypass the working ports and travel directly to the steering box which is essentially what it did before Leroy s modifications But once the valve lever is pulled to activate the lifting cycle live fluid is directed to the cylinders lower chambers which lifts the bed but also simultaneously forces fluid in the upper chambers to exhaust past the unused working port through the open return circuit in the valve and into the steering box where it s returned to the pump reservoir Conversely when the control valve lever is pushed to lower the bed the cylinder s upper chambers are pressurized and the evacuated fluid on the piston s opposite sides is relievedthrough the valve as before To compensate for the additional fluid required by the cylinders fittings and extra hoses Ric

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