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Cat 320 Boom droping

JRsEquipment · 2022-07-26 22:04

cat 320 Next gen S# HEX. Has a shear that weighs 5400 Lbs, about 25% of the time when you boom down it suddenly drops as if its going to free fall to the ground, 75% of the time it feathers down as it should.

Replies9
  1. #1uffex2022-07-27 03:50

    Good day Have you noticed if how far outreached you are with shear, it maybe that you are opening the shock valves. Kind regards Uffex

  2. #2JRsEquipment2022-07-27 09:22

    Not far out, stick is about 90 degrees

  3. #3uffex2022-07-27 11:21

    Good day I suggest you measure how much pressure you have to hold that shear from the ground in your boom cylinder circuit. Kind regards Uffex

  4. #4JRsEquipment2022-07-27 11:25

    When holding the boom up stationary it's about 2500 PSI on boom up pressure

  5. #5uffex2022-07-27 11:37

    Good day I suggest you monitor the pressure when the equipment begins to drop/sink it may just be a shock valve opening early. The working pressure of those machines will be around, 4900 p.s.i. and shock valves are normally set to a higher level. Across carriage with this shear will the machine remain stable as you reach out, that can give a good indication if the shear is too heavy for the host machine. Kind regards Uffex

  6. #6Ollie2022-07-27 13:29

    Have a couple nex gen cat hoes. The stick out would do it’s own thing u stop and would just shake around dangerous for the guys hooking up pipe etc. there are coils 4 each for lift cylinders and bucket two for stick cylinder took ten min to swap out on the 330 and an hour and a half to recalibrate work like new that was at 1800hr. Just got a 349 300hr same thing couldn’t cut grade really jumpy switched coil out working like new. Cat need to test these things a little better. Have a brand new 336 leaking engine oil

  7. #7John C.2022-07-27 20:49

    Is the shear mounted to the boom or to the stick. I'm not familiar with the next gen machines. Are they pilot controlled or electronically controlled? You should be able to watch the operation of the controls on the monitor panel.

  8. #8Ollie2022-07-27 21:15

    There full eclectic. When we call cat bout are 330 the cat mechanic new right away, they had a customer we’re the boom would dam near free fall and then catch. it’s so easy to be smooth on them if there jumpy somethings wrong

  9. #9Ollie2024-11-10 20:58

    What came of your boom free falling. Did cat come take a look at it?