Repair & Modernization: Hydraulic Power Units (HPUs)
Repair & Modernization: Hydraulic Power Units (HPUs)
We overhaul and recondition hydraulic power units of all configurations: from standardized assemblies to unique engineered systems. Diagnostics, repair, modernization, and performance testing on proprietary test rigs.
Hydraulic Power Units We Service
Scope of Application / Specifics
- Industrial Hydraulic Power Units
For stamping and forging presses, rolling mills and conveyor transfer lines
- Mobile Hydraulic Power Packs
For mobile machinery, transportable equipment and testing stations
- Oil Stations & Centralized Lubrication Units
For centralized industrial lubrication, fluid cooling and off-line filtration systems
- Special-Purpose Hydraulic Stations
Explosion-proof (ATEX), low-temperature execution and units engineered to custom technical specifications
What Does HPU Repair Include?
01
Diagnostics and Defect Analysis
- Visual inspection and surface cleaning of the power unit
- Fluid level verification and condition/cleanliness analysis of the hydraulic fluid
- Measurement of operating pressure, pump delivery (flow rate), and fluid temperature at designated test ports
- Comprehensive diagnostics of hydraulic pumps, valves, and filtration elements
- Identification of external/internal leakages, cavitation noises, and excessive vibration
- Preparation of an inspection report (defect schedule) complete with remanufacturing recommendations
02
Teardown and Decontamination
- Partial or complete teardown of the hydraulic power unit
- Removal of contaminants, sludge, and oxidation products from the reservoir, piping circuits, and filter housings
- Chemical flushing of internal fluid galleries with dedicated industrial flushing media
- Full fluid change when required
03
Pump Assembly Overhaul
- Detailed on the Hydraulic Pump Repair page →
- Reconditioning of drive shafts and pump casings; replacement of rolling bearings and radial shaft seals
- Mandatory dynamic load testing of reconditioned pumps on test benches
04
Hydraulic Control Apparatus Repair
- Detailed on the Hydraulic Manifold and Valve Repair page →
- Repair of directional spool valves, pressure control valves (relief/reducing), and flow control regulators (throttles)
- Precision lapping of spools and valve poppet seats; coordinate boring operations up to Ø 250 mm and depths up to 750 mm
- Replacement of dynamic/static seals, calibrated springs, and solenoid actuator coils
05
Filtration Unit Servicing
- Flushing or replacement of filter elements (Donaldson, HY-PRO, Tempo Filtre)
- Reconditioning of filter bowls/housings and replacement of sealing interfaces
- Inspection and recalibration of differential pressure clogging indicators (visual/electrical)
06
Hydraulic Cylinder Repair (if integrated into the station)
- Detailed on the Hydraulic Cylinder Repair page →
07
Piping, Hardlines, and Fluid Line Connections
- Replacement of worn high-pressure hydraulic hose assemblies (HPH)
- Repair, flaring, or replacement of rigid seamless metal tubing circuits
- Restoration of thread connections and renewal of pipe adapters and fittings
- Custom on-site fabrication or pre-bending of new piping lines according to isometric schematics
08
Machining and Component Reconditioning
- Drive shaft restoration for pumps and hydraulic motors: automated weld overlay (cladding) of worn journals (diameters up to Ø 400 mm, lengths up to 2,000 mm), followed by finish CNC turning (up to Ø 1,000 mm, lengths up to 5,000 mm) and cylindrical grinding
- Fabrication of bushings, connection flanges, and union adapters on CNC turning and milling centers
- Precision line boring of bearing seats and housing bores
- If heavy fabrication is required, in-house machining and custom manufacturing resources are utilized
09
Assembly and Bench Testing
- Mechanical reassembly of the power unit upon completion of all component repairs
- Charging the reservoir with conditioned hydraulic fluid (mineral oils, synthetic fluids, or water-glycol fire-resistant mixtures / HFC)
- Dynamic proof testing on the factory test rig under variable load
- Verification of rated operating pressure and pump flow delivery; checking functional switching of directional and pressure control valves; leak-tightness inspection; acoustic noise and temperature monitoring; issuance of an official equipment technical passport recording actual test performance
10
Modernization (Optional Upgrades)
- Replacement of obsolete fixed-displacement units with energy-efficient variable-displacement pumps (e.g., Bosch Rexroth)
- Installation of high-efficiency multi-stage filtration packages (HY-PRO, Tempo Filtre)
- Integration of programmable automated control systems (PLC/SCADA)
- Detailed on the Hydraulic Equipment Modernization page →
Advantages of Repair at Promgidropryvod
01
Comprehensive Single-Source Approach
We repair all power unit assemblies under one roof: pumps, valves, cylinders, manifolds, and piping lines. No need to coordinate multiple third-party contractors.
02
In-House Component Reconditioning Fleet
Equipped with CNC lathes, milling centers, coordinate boring mills, cylindrical/surface grinding machines, and an automated weld cladding section. We restore worn critical components rather than automatically replacing them, significantly reducing total repair lead times and capital expenditure.
03
Dedicated Full-Load Test Benches
Every overhauled power unit undergoes full dynamic load testing. We issue a certified equipment technical passport detailing actual verified hydraulic parameters.
04
Engineering Modernization Capability
During overhaul, we offer targeted modernization packages: retrofitting obsolete components with modern equivalents to increase overall machine cycle speeds, process precision, and energy efficiency.
The Repair Workflow at Promgidropryvod
01
Receiving & Preliminary Diagnostics
Delivery to the workshop, recording baseline parameters, and taking laboratory oil samples.
02
Defect Schedule & Quotation
Defining the scope of damaged or worn components; agreeing on repair timelines, operations, and commercial costs with the client.
03
Teardown & Fluid Draining
Removal of pumps, valve manifolds, and external hardlines; degreasing and cleaning the reservoir.
04
Division-Specific Component Repair
- Hydraulic pumps and motors are routed to the rotary machine service division.
- Valves, manifolds, and cartridges are routed to the control valving department.
- Hydraulic cylinders are routed to the linear actuator overhaul division.
05
Component Machining & Reconditioning
Line boring, automated cladding, precision grinding, and CNC turning of custom bushings and adapters.
06
Final Assembly & Fluid Replenishment
Mounting reconditioned components back onto the structural skid frame, reconnecting hydraulic lines, and filling with conditioned oil through offline filtration carts.
07
Dynamic Test Bench Validation
Full-load hydraulic performance testing, parameter logging, and signing off the technical passport.
Case Studies: Reconditioned Hydraulic Power Units
Frequently Asked Questions
How quickly do you repair hydraulic power units?
Turnaround times depend on the failure profile and work scope. Standard industrial power units take from 5 business days. Complex multi-circuit installations requiring extensive machining and line boring can take from 1 to 2 months.
What if the power unit is severely worn and requires replacement of most components?
Turnaround times depend on the failure profile and work scope. Standard industrial power units take from 5 business days. Complex multi-circuit installations requiring extensive machining and line boring can take from 1 to 2 months.
Do you carry out on-site diagnostics and field service?
Turnaround times depend on the failure profile and work scope. Standard industrial power units take from 5 business days. Complex multi-circuit installations requiring extensive machining and line boring can take from 1 to 2 months.
Is a full oil replacement mandatory during an overhaul?
Turnaround times depend on the failure profile and work scope. Standard industrial power units take from 5 business days. Complex multi-circuit installations requiring extensive machining and line boring can take from 1 to 2 months.
What warranty coverage is provided on repaired hydraulic power units?
Turnaround times depend on the failure profile and work scope. Standard industrial power units take from 5 business days. Complex multi-circuit installations requiring extensive machining and line boring can take from 1 to 2 months.
Do you machine custom spare parts in-house for repairs?
Turnaround times depend on the failure profile and work scope. Standard industrial power units take from 5 business days. Complex multi-circuit installations requiring extensive machining and line boring can take from 1 to 2 months.
Request HPU Repair Now
Attach photos of the power unit, an image of the equipment nameplate (data plate) or describe the technical issue. Our fluid power engineer will contact you promptly to clarify specifications.