I’m restoring a Caterpillar D6 Serial No. 9U29409 I rebuilt the hydraulic steering control unit, right side still doesn’t work. My service manual doesn’t show anything on the dowels on each side, parts book shows 3 dowels 1 1/2” long and 1 dowel 2 1/8” long. I have 3 dowels on left side and 1 dowel on the right. Can’t get them out and don’t know if there in the right place or not and can’t find any information on it. Any information would be well appreciated
Why are you wanting to remove the dowels? The only thing that may need changing is the inner seal unless you want to dismantle the spool valve.
Thank you for responding. I don’t necessarily need to remove the dowels, I just can’t find any information on them, the parts books shows 2 different sizes 3 are 1 1/2” and 1 is 2 1/8” long. On left side I have 3 dowel holes and a dowel in each hole, the right side I have 2 holes with 1 dowel and 1 empty hole. I don’t have any pressure on the right side, I’m trying to figure out if the dowels have anything to do with pressure or why I don’t have any pressure on the right side, the left side works good. If you have any idea of why I don’t have pressure on the right side please let me know. I would appreciate any help. Thanks, Robert
Thank you for responding. I don’t necessarily need to remove the dowels, I just can’t find any information on them, the parts books shows 2 different sizes 3 are 1 1/2” and 1 is 2 1/8” long. On left side I have 3 dowel holes and a dowel in each hole, the right side I have 2 holes with 1 dowel and 1 empty hole. I don’t have any pressure on the right side, I’m trying to figure out if the dowels have anything to do with pressure or why I don’t have any pressure on the right side, the left side works good. If you have any idea of why I don’t have pressure on the right side please let me know. I would appreciate any help. Thanks, Robert
The dowels are most likely for blocking ports. If all are accounted for it's probably correct. I have a complete steering unit here that I can take a look tomorrow at the right side and see if there is an open port.
Yes, there is an open port on the RH side. Have you dismantled the plunger/valve on that side, may be stuck.
Thank you for responding. Mine looks just like that, I completely disassembled this whole valve body, had to make a tool to get the small seals out, removed pistons and valves, they were in good condition so I cleaned them up and reassembled it. Took it back off the machine today, this is my second time going into it, I’m going to disassemble the right side and make sure the valve is not stuck. I’m sending a picture of what mine looks like. Do you know of anything else would cause it to not have pressure on the right side. Do you know of any place I can get a rebuilt valve body or do you know of anyone that rebuilds them. Thank you so much. Robert
If one side is getting flow and pressure then there is nothing wrong with the porting. You need to look into the valve & spool. I don't offhand know of a source for parts but this unit was common to the D6, D7, D8 so parts, new and used should be around. Even Cat may have them. Do you have the Servicemen's Reference for the D6? It has a pretty good description of how it works and the fluid flow. Nobody specializes in rebuilding that I'm aware of but complete used units should be readily available as they seldom have a problem.
Do you mean this one.? I know it's not an OEM one but it appears to be a bretty good reproduction of the original if the photos are anything to go by. Service Manual Set For Caterpillar D6 Crawler Tractors 4R 5R 8U 9U Repair Shop | eBay Serials starting with 4R, 5R, 8U and 9U. Model D6 Crawler Tractors. This manual set will help you Operate. Tractor Service / Repair Manual. Engine Service / Repair Manual. Complete Table of Contents for Each. www.ebay.com
I was referring to this one. An original will have the best quality illustrations. Service Men’s Reference Book Caterpillar D6 Tractor G1 | eBay The book covers all aspects of the tractor, from the engine and transmission to the brakes and hydraulics. With clear diagrams and step-by-step instructions, it's easy to follow along and complete any necessary repairs or maintenance. www.ebay.com