A leaking cylinder or a seized valve doesn't mean a new power unit. If the spool, gland, or piston is obsolete, it can be machined again — pressure-rated and sealed — from your worn original.
Hydraulic systems are built to last decades, but the precision wear parts inside them — valve spools, cylinder glands, piston assemblies — are revised or dropped from the catalogue long before the machine retires. When a press, lift, or excavator goes down for a part nobody stocks anymore, the choice isn't "buy new equipment." It's reproduce the part.
Unlike a simple bracket, a hydraulic part has to seal under pressure, so accuracy and surface finish matter more than usual. That's exactly what machining controls well — often better than the worn original ever did.
| Part | Why it fails | Typical material |
|---|---|---|
| Valve spool & body | Scoring, sticking, internal leakage | Hardened 1045 / 4140, ground |
| Cylinder gland / head | Seal groove wear, corrosion | 4140 steel, ductile iron |
| Piston & rod | Scoring under the seal, pitting | 17-4 PH or hard-chrome rod |
| Manifold block | Cracked ports, stripped threads | Ductile iron, aluminum, steel |
| Port adapter / fitting | Thread & o-ring face wear | Steel, stainless |
We don't remake the elastomer seals — those are standard items we help you cross-reference to a current supplier. We make the precision metal parts the seals run against.
A hydraulic part leaks for one of two reasons: wrong dimensions or wrong surface finish. Dynamic sealing surfaces need a controlled Ra 0.2–0.4 µm finish — too rough and the seal wears fast, too smooth and it can't hold a lubricating film. We grind and finish sealing surfaces to spec and verify bore and rod tolerances on a CMM. See our tolerance & inspection capability.
Worth a quick search of obsolete-parts dealers — but truly discontinued spools and glands are often unobtainable.
If only the seals failed, a reseal kit may fix it. If the metal is scored or out of tolerance, no seal will hold — the part itself needs remaking.
Send the worn part; we reconstruct the geometry, finish the sealing surfaces correctly, and machine a compatible replacement. See reverse engineering.
Mail the worn part where possible — measuring a sealing bore by hand is unreliable. Include the system pressure and the fluid. No drawing? Start with no-CAD ordering; we confirm every critical dimension before cutting. The approach is the same one we use to replace discontinued pump parts — the difference is that hydraulics live or die on the seal-surface finish.
Upgrade while you're at it. A rod that kept pitting can come back hard-chrome plated; a manifold that cracked can be re-cut in a tougher alloy. A discontinued part is a chance to fix the original weakness.
Yes. Sealing comes from dimensional accuracy and surface finish — we machine bores and rods to the right tolerance and Ra (typically 0.2–0.4 µm on dynamic surfaces) and pressure-test critical assemblies.
Valve spools and bodies, cylinder glands and heads, pistons and rods, manifold blocks, port adapters and fittings, and seal housings. Seals themselves are standard items we help you source.
No. Send the worn part or clear photos with key dimensions and the system pressure. We reconstruct and confirm critical sizes before machining.
Commonly 1045/4140 steel for bodies and pistons, 17-4 PH or hard-chrome rod for sealing surfaces, ductile iron or aluminum for manifolds — matched or upgraded to your pressure and fluid.
Send the worn part or photos + system pressure. Engineers reply within 24 hours.
No drawing needed · Files kept confidential