Every maintenance engineer eventually faces the same moment: a critical hydraulic component fails, you call the OEM, and the answer is either "discontinued," "16-week lead time," or a price that makes you question whether the equipment is worth keeping. At that point, you have a decision to make.
This guide walks through the five scenarios where reverse engineering is clearly the right call, the three scenarios where you should still order OEM, and what the reverse engineering process actually looks like when done properly with SolidWorks professional CAD software.
WHAT IS REVERSE ENGINEERING FOR HYDRAULIC PARTS?
Reverse engineering means taking a physical part — worn, broken, or intact — measuring every critical dimension, and creating a new engineering model from those measurements. In a proper reverse engineering workflow, that model is built in parametric 3D CAD software (we use SolidWorks), validated against the original, and then used to produce a new part on CNC machining equipment.
The result is not a "copy" in the counterfeit sense — it is an engineered replacement that meets or exceeds the original specification. In many cases, the reverse-engineered part is actually better than the original because the engineer can address known failure modes in the redesign.
A SolidWorks exploded assembly model of a hydraulic cylinder — the starting point for any reverse engineering project at Mercury Hydraulics.
5 SCENARIOS WHERE REVERSE ENGINEERING IS THE RIGHT CALL
The Part Is Discontinued
This is the most common scenario. Equipment outlives its OEM support. Manufacturers discontinue part numbers, get acquired, go out of business, or simply stop stocking slow-moving components. If the OEM says it's discontinued and no aftermarket supplier carries it, reverse engineering is often the only option short of replacing the entire machine.
Lead Time Is Unacceptable
A 12–16 week OEM lead time on a part that's keeping a vessel docked, a production line stopped, or a piece of defense equipment grounded is not a viable option. Reverse engineering from an existing sample can often produce a replacement part in days to a few weeks — especially when CAD modeling and machining are done under the same roof.
The OEM Price Is Unreasonable
When OEM pricing reaches 3–5x the cost of a reverse-engineered equivalent, the economics shift decisively. This is especially common with proprietary components on older equipment where the OEM knows they have a captive market. A properly reverse-engineered part at 30–40% of OEM cost, with equivalent or better quality, is a straightforward business decision.
The Part Has a Known Failure Mode
If you've replaced the same component three times in two years, the OEM design has a weakness. Reverse engineering gives you the opportunity to redesign that weakness out — upgrade the material specification, change the seal groove geometry, add a wear surface, or modify the load path. You're not just replacing the part; you're solving the problem.
The Equipment Is One-of-a-Kind
Custom-built machinery, prototype defense systems, legacy aerospace equipment, and one-off marine vessels often have components that were never commercially available in the first place. The only way to get a replacement is to make one. This is where reverse engineering isn't just a cost decision — it's the only path forward.
3 SCENARIOS WHERE YOU SHOULD STILL ORDER OEM
Reverse engineering is not always the answer. There are situations where ordering from the OEM is still the correct choice:
The Part Is Under Warranty
If the equipment is still under OEM warranty, using a reverse-engineered replacement may void it. Unless the warranty is already expired or the OEM has failed to provide timely support, ordering original parts protects your warranty coverage.
Regulatory Certification Is Required
Certain aerospace, nuclear, and medical applications require parts with specific OEM traceability documentation, material certifications, and test records that cannot be replicated through reverse engineering. In these cases, the regulatory requirement overrides the economic argument.
The OEM Price and Lead Time Are Reasonable
If the OEM part is available, priced fairly, and can be delivered within your operational window, there is no compelling reason to reverse engineer it. The goal is to solve the problem efficiently — not to reverse engineer for its own sake.
WHAT THE REVERSE ENGINEERING PROCESS LOOKS LIKE
When a customer brings us a part for reverse engineering, here is exactly what happens:
Physical Inspection
We examine the part for wear patterns, failure modes, material characteristics, and surface finish requirements. This tells us not just what the part is, but why it failed — which informs the redesign.
Dimensional Survey
Every critical dimension is measured using precision instruments — digital calipers, micrometers, bore gauges, and where needed, CMM (coordinate measuring machine) measurement. We document tolerances based on function, not just nominal dimensions.
SolidWorks Modeling
The part is modeled in SolidWorks as a fully parametric 3D model. This means every dimension is driven by a parameter — if a tolerance needs to change, one number updates the entire model. The model is checked against the physical part before any machining begins.
Engineering Drawing
An ASME Y14.5 compliant engineering drawing is produced with full GD&T callouts, material specification, surface finish requirements, and any special notes. This drawing becomes the permanent record for the part — used for the first production run and every repeat order after.
First Article Inspection
The first machined part is inspected against the drawing before delivery. Dimensions are verified, surface finish is checked, and where required, the part is pressure tested or functionally tested in a representative assembly.
WHAT YOU NEED TO BRING US
The minimum requirement for a reverse engineering project is the physical part itself — or, if the part is destroyed, a description of its function and any dimensions you can measure. The more information you can provide, the faster and more accurate the result:
NEED A PART REVERSE ENGINEERED?
We've reverse engineered hydraulic components for the Department of Defense, commercial marine operators, aerospace contractors, and RV owners who couldn't find what they needed anywhere else. If you have a part that needs to be replicated — or a design that needs to be improved — call us.