AIR CONTROL VALVE GROUP 4Y0400 - Caterpillar

(1) Lower the scraper bowl to the ground and put stands under the front of the tractor and under the scraper draft frame as shown. Remove steering cylinders (1) and steering links (2). Remove kingpins (3) and make a separation of the tractor from the scraper; see the Service Manual. (2) Put punch marks on each side of the draft frame. Measure the distance from the punch marks to the center of the pin bores at the top and bottom of housing (4). Make an accurate record of those dimensions; they will be needed to put the new housing in position for welding. If the housing is badly damaged, these measurements will not be used. (3) Remove the tubes, clips, clamps and other hardware from each side of housing (4). Use a cutting torch to make straight through (90°) cuts in the center of the welds across the top and along each side (A) of the housing. Use an Arcair torch or similar tool to remove the welds along the bottom and along the outside at (B). Use the cutting torch to cut away the front part of housing (4) to get access to the weld along the inside of the housing at (B). Fasten a hoist to housing (4) [approximate weight is 585 kg (1300 lbs.)]. Use the Arcair torch to remove the inside welds and remove the housing. Remove all back up material and welds. Grind smooth all the torch cuts and remove all weld slag and weld material. (4) Put 4T7694 Kingbolt Housing (5) [approximate weight 585 kg (1300 lbs.)] in position on the draft frame with the top of the housing under the top plate at (C). Lift the housing until it makes contact with the top plate. Put the bottom of the housing against the bottom plate at (D). If necessary, trim (cut away) the housing to get less than 3.0 (.12") between the housing and the bottom plate. Measure the distance from each side of the draft frame to the bearing bore at the bottom. Put the lower pin bore in position an equal distance from each side of the draft frame. Check the dimensions shown to be sure they are correct. Tack weld the housing in position. Install the steering cylinders, steering links and pins. This will help make sure that the housing is in the correct position. If the housing is in correct position, disconnect the steering cylinders and move them to get access for welding. (5) The size and description of the welds around the housing are: *Flush J-groove**Fillet***Bevel groove(6) When the housing is in the correct position, make the first weld pass in the bottom of the grooves at (Y) and (Z). Start at the outside and weld toward the center. Make the first weld pass along sides (W) and (X) from the bottom to the top. Use the welding procedure that follows to make the welds as shown above. a) Make weld