Discussion:
Hydraulic "hard knock" on motor start

My ERC040 Electric has started knocking when I start the hydraulics. By knocking I mean that when the hydraulic motor starts, it pops hard - like a whack with a hammer. As soon as the motor comes on - BANG - but if I operate the hydraulics quickly, there is no knock after the initial knock, provided I don't let the motor rest too long (let the pressure drop too much).
I suspect there is some kind of adjustment that softens the startup, such as an initial pressure relief on motor start. I think the motor is currently supplying 100% hydraulic pressure immediately on start. It used to start smooth and quiet. Has anyone adjusted this setting and can you tell me where it is if you have? Thanks in advance.
  • Posted 21 Nov 2023 03:52
  • By Tomisaburo
  • joined 21 Nov'23 - 3 messages
  • California, United States
One day I will be rich
Showing items 1 - 5 of 5 results.
oh boy, a military built lift.. that explains why i don't have that one.
gonna have to give me a bit to get that, i don't have access to that system till monday. i'll get back to you asap.
one thing i might need to know is what type of controller is in it, (it could be either AC drive or DC drive, and if you can put eyes on the pump motor is it enclosed or does it have vents on it? if you can see the tag on the motor maybe a part number? anything would be helpful. If not that's ok.
  • Posted 25 Nov 2023 09:27
  • By swoop223
  • joined 23 Mar'12 - 3,691 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
OK.. here it is
ERC040AHN36TE084
Ser# B814N01865C

I bought it from DECA at Edwards AFB after the battery leaked on the motor and locked the robot. It has been very handy here at my office

Jerry
  • Posted 25 Nov 2023 08:16
  • By Tomisaburo
  • joined 21 Nov'23 - 3 messages
  • California, United States
One day I will be rich
whats the whole model number? (and serial if you have that)
  • Posted 25 Nov 2023 07:19
  • By swoop223
  • joined 23 Mar'12 - 3,691 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
I think you might be right. It is only on start. Thanks for the response. I will see what it takes to remove that motor and replace the coupling. It is odd that it was so sudden. Usually a keyway takes time to come loose. Or maybe it is like a lovejoy and the rubber spider has failed. I wish I had a parts breakdown.
JB
  • Posted 25 Nov 2023 02:39
  • By Tomisaburo
  • joined 21 Nov'23 - 3 messages
  • California, United States
One day I will be rich
that knock is either the motor mount or maybe the coupler between the motor and the pump.
  • Posted 24 Nov 2023 14:00
  • By swoop223
  • joined 23 Mar'12 - 3,691 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com

Post your Reply

Forkliftaction accepts no responsibility for forum content and requires forum participants to adhere to our rules of conduct. Click here for more information.

If you are having trouble using the Discussion Forums, please contact us for help.

Global Industry News
edition #1238 - 10 July 2025
This week Forkliftaction News is celebrating its 25th anniversary! A wonderful achievement given we launched at a time when just 6% of the world’s population were internet users, according to Internet World Stats . Over the coming weeks, we will be sharing stories about our history and rolling out more celebrations, so keep an eye out... Continue reading
Hangcha CBD15
China
Used - Sale
USD1,600
SMV (Konecranes) 20-1200B
Balling, Denmark
Used - Sale
Upcoming industry events …
September 23-25, 2025 - SÃO PAULO, Brazil
October 15-16, 2025 - Las Vegas, United States
November 25-26, 2025 - Singapore, Singapore
Movers & Shakers
Laura Ness Owens Laura Ness Owens
Chief marketing officer, Bobcat Company
Chief commercial officer, Teradyne Robotics
CEO, MHEDA
President, European Rental Association (ERA)