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Cat 301.8 bypass 2 speed travel pilot line.

hmcs01 · 2025-09-27 10:36

Hi all, Need some help figuring out how to bypass the 2 speed system on my 2001 cat 301.8 sn# BFA01712, this is a new to me machine and was a little short on maintenance by previous owner Issue is the top hose on the right side travel motor has developed a significant leak at the end of the hose due to corrosion and when machine sits for a couple days it drains the hydraulic tank. It looks like I may need to replace the complete travel motor to fix it properly as it was packed with mud/clay and is now pretty badly corroded. I am hoping I can just block off the 2 speed system and run like that until I can get the necessary parts collected to repair it properly

Replies6
  1. #1Nige2025-09-27 11:02

    Here is the travel lines breakdown from the parts manual if it is any help.

  2. #2hmcs012025-09-27 12:05

    Thanks Nige! Do you happen to have a diagram that shows which port on the swivel thing is the one that sends the 2 speed travel pilot signal down into the undercarriage? I am thinking that if I pull the pilot line off the swivel in the house and cap both ends that should get me by for now. Also do you happen to know what size ORB fittings they are so I can get a plug and cap Thanks again!!!

  3. #3Nige2025-09-27 16:08

    Here's the lines above the swivel. Generally speaking there is an easy way to identify the travel lines by diameter going from the largest to the smallest. The two identical size hoses are the motor FWD & REV drive. The next smaller hose below those two is for the parking brake release. The smallest hose of the four is the 2-speed.

  4. #4hmcs012025-09-27 21:13

    Thanks Nige! I blocked off the smallest hose which connects to top port on the swivel marked as D in that diagram but I am still getting a slow leak, the amount of oil seems more than what would have been residual in the lines. So not sure if that was the correct line

  5. #5hmcs012025-09-28 18:01

    Can anyone confirm the ports on the travel motor, all the lines appear to be the same size so I can’t determine which is the 2 speed pilot line by size alone. I am trying to figure out what the line is that comes out the top of the travel motor. Even when I block off the pilot line up in the house I still get a slow leak of fluid from that line. So I am wondering if that top line is the case drain from the motor.

  6. #6Nige2025-09-29 04:18

    I have to hold my hands up here. I forgot this model is so small that it doesn't have a separate pilot line to release the parking brake. The small line from the top of the motor is the case drain. On the hydraulic schematic it is marked "T" (tank)