Multiquip 521139 Wrist Pin

The Multiquip 521139 Wrist Pin is a genuine OEM component designed for LS300P, LS300G, LS600P, and LS300GK hydraulic-driven concrete pumps. As a factory-sourced replacement, it is manufactured to the exact tolerances required to maintain proper piston-to-connecting-rod alignment within the pump's hydraulic drive system. This wrist pin is a direct-fit replacement for Multiquip LS-series concrete pumps, ensuring a straightforward installation without improvisation or modification to surrounding components.

Key Features

• Precision-Toleranced OEM Construction — Manufactured to Multiquip's exact dimensional specifications, ensuring correct bearing surface contact and load distribution within the piston assembly.
• Direct-Fit Replacement — Engineered to drop into the existing piston bore and connecting rod on LS-series pumps, aligning with factory pin bore dimensions for a clean, secure installation.
• Confirmed Fitment for LS-Series Concrete Pumps — Compatible with LS300P, LS300G, LS600P, and LS300GK models, covering a range of hydraulic-driven Multiquip concrete pump configurations.
• Maintains Pumping Stroke Integrity — A correctly fitted wrist pin keeps the piston and rod in precise alignment through every pumping cycle, sustaining consistent concrete output pressure and volume.
• Critical Wear Component — Wrist pin wear or failure leads to slop in the piston assembly, causing uneven stroke, accelerated cylinder wear, and loss of output pressure — replacing it proactively protects the surrounding drivetrain components.

The wrist pin — also called a piston pin — connects the piston to the small end of the connecting rod inside the pump's hydraulic drive cylinder. It serves as the pivot point through which force is transferred from the rod to the piston on each pumping stroke. When a wrist pin wears, becomes loose, or seizes, it creates play or binding in the piston assembly, which disrupts the pumping stroke, reduces output consistency, and can cause rapid secondary damage to the cylinder bore and connecting rod bearings. Replacing a worn wrist pin with a genuine OEM part like the Multiquip 521139 restores the tight, controlled movement the pump depends on for steady, reliable concrete delivery.

Part Details

Compatibility & Fitment

Verify Before You Order

Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.

Why Buy From DHS Equipment

Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.

Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.