Background
A major manufacturer experienced a critical failure on their 400-ton compression moulding press, with output capacity reduced to only 250 tons. This significant loss of power created production downtime and risked costly delays. Hydraulic Distributors was engaged to diagnose the root cause, implement repairs, and establish preventive measures to avoid recurrence.
Challenge
The machine’s power loss was complex, involving multiple system areas:
- Electrical signal interruptions to hydraulic components
- Pressure loss from leaks and defective hoses
- Flow restrictions and pump inefficiency
- Potential mechanical misalignment and contamination concerns
The goal was to restore full operating pressure, eliminate failure points, and implement an annual preventive maintenance framework for long-term reliability.
Diagnosis & Fault Isolation
1. Electrical / Control Issues
- DIN Plugs (C-Top 3 valve): Defective plugs and poor-quality replacements were preventing solenoid valves from actuating correctly.
- Valve Spool Movement: C-Top 3 valve was sticking, leading to unreliable control response.
- Electrical Collaboration: Worked in conjunction with electrical specialists to isolate hydraulic vs. electrical faults.
Action: Replaced all C-Top 3 valve DIN plugs, tested valve response post-installation, and replaced proportional valves (x4).
2. Hydraulic Leaks & Pressure Loss
- Leaky Hose: Pressure drop on retraction traced to poor-quality hoses.
- Valve Bank Stack: Required new O-rings due to internal bypass leakage.
- Cylinder Damage: Ram seal failure contributed to bypass loss.
Action: Installed new hoses, rebuilt leaking valve stack with fresh seals, and repaired damaged cylinder ram.
3. Flow Restrictions & Blockages
- Pump & Filter: Old pressure-compensated pump underperforming, with clogged filters restricting supply flow.
- Non-Standard Parts: The pump’s mounting flange and shaft were non-standard for Australia, requiring an overseas supplier.
- Contamination Risks: Dirty filters and reservoir required cleaning.
Action: Replaced pump and filter with OEM-specified units, flushed system, cleaned reservoir, and installed new tube assembly seals and O-rings.
4. Circuit Element Faults (Retract-Side Specific)
- Flow Controls / Orifices: Blockages in the retract leg limited return flow.
- Return Line Restrictions: Blocked return filter caused back pressure.
- Relief Valve: Pressure setting was too low, causing premature cracking and trapping pressure.
Action: Flow controls cleaned, return filter replaced, relief valve pressure reset.
5. Supply-Side & Fluid Condition
- Oil Viscosity & Condition: Sample sent for analysis; results confirmed correct viscosity and no contamination.
- Reservoir Hygiene: Reservoir and tanks cleaned to prevent varnish buildup and cavitation risk.
6. Mechanical & Alignment
- Mechanical inspection confirmed no misalignment, dragging, or jamming of the press structure.
Implemented Solutions
- Hydraulic Overhaul
- Replaced defective DIN plugs (C-Top 3 valve)
- Installed new proportional valves and pressure switch/transmitter
- Rebuilt valve bank stack with O-rings
- Repaired damaged ram seals
- Replaced hoses, pump, and filters
- Cleaned and resealed tube assemblies & 4-bolt flanges
- System Optimisation
- Relief valve pressure recalibrated
- Flow restrictions removed from orifices and return lines
- Reservoir hygiene & system flush
- Gauges connected for live pressure monitoring
- Validation & Testing
- Function acceptance testing under load confirmed 400T capacity restored
- Joint sign-off with electrical specialist
Results
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Preventive Measures
To prevent recurrence, Hydraulic Distributors recommended an annual maintenance schedule based on the duty cycle of the press:
- Scheduled filter replacements and oil analysis
- Routine reservoir hygiene checks
- Annual inspection of valves (sandwich, counterbalance, sub-base mounted, and flow controls)
- Proactive replacement of wear-prone seals and O-rings
- Ongoing electrical-hydraulic diagnostic collaboration
What sets us apart?
- Expertise across hydraulics and controls: Our engineers and technicians bring over 160 years of combined hands-on experience in fault diagnosis and repair.
- Global sourcing ability: We specialise in sourcing hard-to-find, non-standard OEM components from international suppliers.
- End-to-end service: From electrical diagnostics to hydraulic repairs and rebuilds, we ensure seamless integration on every job.
- Long-term reliability: Our team provides more than repairs, we deliver a complete preventive maintenance framework tailored to your system.
Issues with your industrial press? Our engineers can diagnose retraction stalls, signal issues, and supply restrictions, then implement a lasting fix — fast!
Call us to book an assessment on 02 8608 2144 or ENQUIRE ONLINE
