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Recent content by Weekend_Warrior

  1. W

    Cat 277C Parking Brake Won't Disengage

    Nige, As I was reading the diagnostic guide you provided, I realized that the parking brake solenoid and pilot hydraulic pressure solenoid shared a common wire, the H807 yellow wire that I cut and spliced in. So at some point in the wiring harness the two yellow wires from both solenoids merge...
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    Cat 277C Parking Brake Won't Disengage

    Thank you for the troubleshooting guide, Nige. Looks straight forward like the one for the parking brake valve. I'll try to troubleshoot this week, but for sure during the week. The parts manual shows it to be component #2 below. I couldn't find a better picture showing the location of the...
  3. W

    Cat 277C Parking Brake Won't Disengage

    I don't think I did as I only worked on the plugs for the parking brake solenoid and speed sensors. I didn't disconnect any other small plugs, but I did disconnect all of the large square plugs (the ones with 20+ wires) that I could identify to check for corrosion, but re-installed them...
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    Cat 277C Parking Brake Won't Disengage

    Your intuition is correct. I am embarrassed to post this as the issue really was an open circuit in the wiring. When I performed the continuity test a few weeks back I thought the meter was measuring "micro" Ohms, but in fact it was showing "MEGA" Ohms so the circuit was wide open. As Zewnten...
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    Cat 277C Parking Brake Won't Disengage

    Thanks for the additional details, Nige. Fought a lot of fires this week so I wasn't able to test the old parking brake solenoid. I also left it at the work office after a show and tell with the Lads, so I won't get to test it this weekend either. Today I checked the speed sensor wires and...
  6. W

    Cat 277C Parking Brake Won't Disengage

    That's actually very possible and a good thought to check. I was on a mission and sprayed a heck of a lot of water all around.
  7. W

    Cat 277C Parking Brake Won't Disengage

    Thanks, Nige. I don't think it's the speed sensors since I did not disturb that area. And for both sides to be out simultaneously that would be too much of a coincidence. I think I smell what you are stepping on now. You're wanting me to function test the old valve to verify if it was even...
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    Cat 277C Parking Brake Won't Disengage

    I like your sense of humor, Nige. I didn't test the old solenoid as I didn't see the point since the new valve came with a new solenoid. What's strange is that after sitting for a few days the parking brake will disengage momentarily and then lock up again and stay locked up. Over the past 2...
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    Cat 277C Parking Brake Won't Disengage

    I thought I discovered the issue but got kicked down again. I pulled the parking brake valve and discovered that the snap ring and screen on the end was missing. Figured that was my issue since the valve was clearly not operating anymore. Whatever components inside the valve are no longer in...
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    Cat 277C Parking Brake Won't Disengage

    Here is an interesting post I found with somebody dealing with the same issue on a Cat 262C: https://www.justanswer.com/construction-and-road-equipment/89825-262-one-side-will-not-release-park-brake.html The technician brought up the possibility of the metal nut on the solenoid being an issue...
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    Cat 277C Parking Brake Won't Disengage

    I was in service Active Service Mode 1. Knowing that the drain ports on the bottom of the machine have been plugged ever since I owned it, I am starting to agree with you that there may be a condensation, corrosion problem. But isn't it strange that this problem occurred immediately after I...
  12. W

    Cat 277C Parking Brake Won't Disengage

    Thank you for the feedback. I unplugged the solenoid, jumped the two contacts, and then checked codes. Code did not change. I did not check wire end to wire end, but that's a good suggestion and I will give that a try. I did check white to yellow and there was continuity. I did tug on the...
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    Cat 277C Parking Brake Won't Disengage

    Thanks, Nige. I found the solenoid and performed the tests from the procedure you sent. Unplugging from the solenoid and jumping the A958-WH(White) to H807-YL(Yellow) wires did not change the diagnostic code from 681-05 to 681-06. This means my solenoid is still good. Unplugging the J2...
  14. W

    Cat 277C Parking Brake Won't Disengage

    Thanks for the tip. Are there supposed to be more than 4 pages in the file that you sent? Asking because I cannot find any hyperlinks. I see the schematic for the parking brake switch, but not the solenoid. If I am viewing the file incorrectly then please let me know.
  15. W

    Cat 277C Parking Brake Won't Disengage

    Thank you for the troubleshooting procedure, Nige. I looked through the parts manual and cannot locate the parking brake solenoid. I'm not sure where it is, but some google searches led me to think it's this component circled in red below. Is this accurate?
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