Description

Williams Controls WM526, WM528, WM540, WM531, WM534 Parts Catalog

If you’re a diesel tech or fleet manager, you know the headache of tracking down the right part number for a throttle assembly. Aftermarket catalogs slap generic numbers on a box and call it a day. Then the pedal doesn’t match the bracket, the sensor throws a code, and you’re burning billable hours chasing the wrong part. The Williams Controls WM526, WM528, WM540, WM531, WM534 Parts Catalog is the original factory document used by Williams Controls themselves. It’s 44 pages of OEM part breakdowns, application data, and ordering info. Part numbers are direct from the factory.

Electronic Foot Pedal Assemblies WM526, WM528, WM540

The first section, starting on page 1, lists the electronic foot pedal assemblies. The WM526 is a suspended pedal, common in Navistar and Volvo applications. The WM528 and WM540 are treadle-style pedals. Each entry includes the base part number and notes on sensor compatibility. If you need to replace a pedal on a Freightliner Century Class, you’ll want the WM528 with the correct sensor kit from page 3.

Remote Sensor Assemblies WM531, WM534, and WM526 Variants

Remote sensors mount away from the pedal, often on the firewall. The WM531 and WM534 are compact units used in space-constrained chassis. The WM526 also appears as a remote sensor variant. Having the OEM parts catalog means you can identify the exact bracket, sensor, and harness parts without relying on a cross-reference that might be wrong.

Pneumatic and Hydraulic Products: What You Get

This catalog doesn’t stop at electronic pedals. It covers pneumatic cylinders (WM386, WM642), transmission modulators (WM775B), pneumatic regulating valves (WM90, WM90DX), and multiple pedal variants (WM453, WM476). Hydraulic products include the WM512C cylinder and WM511C, WM515C pedals. All dimensions are in inches. Each assembly includes an exploded view with callouts for individual components like springs, seals, and mounting hardware. This lets you order exactly the broken piece, not the whole assembly.

Page 3: Application Data for Sensor Kits

The real money table is on page 3. It maps engine sensor kit part numbers to specific chassis and ECM combinations. For example, a Freightliner 1E Class 8 with Caterpillar uses kit 132484; with Cummins it’s 132034; with DDEC III it’s 132035. Treadle pin kit 130553 applies across most Freightliner models. You also get sensor part numbers for Peterbilt, Western Star, Navistar, Volvo, and others. This table alone saves you from ordering the wrong sensor and losing time restocking it.

Ordering Information and Part Number Verification

The catalog includes contact numbers for technical services (503-684-8623) and orders (800-547-1889). A disclaimer states Williams Controls reserves the right to modify products without notice. Having the factory document means you’re working with the original supersession data, not a third-party reprint that might be outdated. Cross-reference your existing part against this catalog before you place an order.

For torque specs and installation procedures, you’ll need the service manual for your specific model. This is purely a parts catalog. But if you’re building a parts order for a fleet of trucks, this 44-page document is your cheat sheet. Automotive Industry Overview provides broader context on throttle-by-wire systems, but for part numbers, stick to this.

Understanding how the ECM interprets pedal position helps for diagnostics. Internal Combustion Engine covers the basics of engine control.

Direct from the source. That’s what you get.

Frequently Asked Questions

Does this manual include torque specs for installation?

No.

Can I find wiring diagrams for the electronic pedals?

This is a parts catalog, not a service manual. It lists part numbers, application data, and exploded views. For wiring diagrams, you need the corresponding service manual from Williams Controls.

What engine ECMs are covered in the application table on page 3?

Page 3 lists sensor kit part numbers for Caterpillar 132484, Cummins 132034, DDEC III 132035, and many others across Freightliner, Peterbilt, Western Star, Navistar, Volvo, and more. It covers both electronic and treadle pin kits. This table alone saves you from guessing which sensor matches a 2003 Century Class with a Cummins ISX. You can reference it to verify compatibility before ordering.

Is this catalog still current for newer trucks?

Williams Controls reserves the right to modify products without notice, as stated in the catalog. This document covers the listed models; always verify supersessions directly with Williams Controls.

When you’re ready to stop chasing part numbers and start ordering the right components, access the factory manual. Massey-Harris-Ferguson FF 30 GS 1957 Parts Catalog | OEM Fastener Guide may help if you work on older equipment, and Futura Wear Technology Parts Catalog covers wear parts. For tractor-specific parts, see LANDTRAC TRACTOR Parts Manual Models 410-550 DTC – Section: Numerical Index. Keep this catalog in your digital library and reference it every time a throttle assembly comes into the bay.