Hydraulic System Won’t Build Pressure: What’s Really Going On

If your machine runs but won’t lift, push, or steer — chances are your hydraulic system isn’t building pressure. This isn’t always a pump failure. It’s often a valve, relief setting, or suction issue that’s robbing your flow.

Common Causes of No Pressure

  • Stuck open relief valve: Dumps fluid back to tank before pressure builds
  • Air in suction line: Prevents pump from drawing fluid efficiently
  • Clogged suction screen: Restricts flow to the pump inlet
  • Broken pump shaft or coupling: Engine spins, pump doesn’t turn
  • Spool valve failure: Blocked or bypassed flow path

How to Test It

  • Check pressure with a test gauge at main circuit
  • Look for frothy or aerated fluid in the tank
  • Use thermal imaging to spot non-moving fluid lines
  • Manually inspect pump shaft and suction side for obstructions

Fixes Based on Diagnosis

  • Adjust or replace stuck relief valve
  • Flush suction line and clean inlet screens
  • Rebuild or replace pump if mechanical damage is found
  • Repair or replace directional control valve section

Conclusion

When hydraulics stop producing pressure, don’t just swap the pump. Run a full diagnostic. Many “dead” systems are caused by relief valves or suction issues that are faster — and cheaper — to fix than replacing core components.

Subscribe
Privacy Policy

If you would like to receive text messages from Marine Squadron, text START, YES, to: (888) 373-7755  You will be opting-in to text messages. Message frequency varies and may include replying to customer questions and inquiries. Message and data rates may apply. You may opt out at any time by replying STOP or CANCEL to (888) 373-7755 at any time to end or unsubscribe. See our Privacy Policy for details on how we handle your information.

Tiden LLC DBA Marine Squadron respects your privacy. By opting into our SMS messaging service, you agree to the following terms regarding how we handle your data:
  • Data Collection: We will collect your name, email address, mailing address, and mobile phone number when you sign up for SMS updates. The information will be collected via SMS once the customer provides opt in consent by texting START, YES to the phone number (888) 373-7755.
  • Data Usage: We use your data solely for replying to customer questions and inquiries.
  • Data Security: We protect your data with secure storage measures to prevent unauthorized access.
  • Data Retention: We retain your information as long as you subscribed to our SMS service. You may request deletion at any time.
  • Contact Tiden LLC DBA Marine Squadron at (888) 373-7755 or mail@marinesquadron.com for HELP or to STOP receiving messages.
  • MESSAGES AND DATA RATES MAY APPLY: Your mobile carrier may charge fees for sending or receiving text messages, especially if you do not have an unlimited texting or data plan.
  • Messages are recurring, and message frequency varies.
  • Opt-Out: You can opt out of the SMS list at anytime by texting, emailing, or replying STOP or CANCEL to mail@marinesquadron.com or (888) 373-7755. After unsubscribing, you will receive a final SMS to confirm you have unsubscribed and we will remove your number from our list within 24 hours.
  • You can send HELP for additional assistance, and you will receive a text including our Phone number, email and website. We are here to help you.
  • Non-Sharing Clause: We do not share your data with third parties for marketing purposes. Tiden LLC DBA Marine Squadron will not sell, rent, or share the collected mobile numbers.
Whatsapp Text Message Rapid Response Duty Officer