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Cat 277b Aux hylraulics running slow

63 caveman ยท 2018-09-13 11:54

Hello all, I'm tring to figure out a slow aux. hyro problem, serial # MDH00903 with standard pump (no high flow). I have 7.9 vdc between pins 1 and 2 on right joystick 12 pin connector and have 53.3% in neutral on pin 3 going smoothly between 56.9% to 43.0% with thumb wheel. All other hydro function work at normal speed. Are the % readings in normal range? DO you think I may have a leaking (bypassing internal) Aux. spool valve?

Replies2
  1. #1Mark2502018-09-13 16:36

    no the duty cycle is way to low The voltage to the controller is 8 VDC so that is ok Mark

  2. #263 caveman2018-09-13 17:11

    Thanks Mark, I checked another machine and it went from 20% to 80% just like the graph you posted. $400 USD later for new switch and it is working right. It would have been easy for me if it was just dead. Thanks Again