Kenworth W900B/W900L Brake Parts & Acc.

Frequently Asked Questions About Kenworth W900B/W900L Brake Parts & Acc.

What's the difference between brake parts for W900B and W900L models, and are they interchangeable?

While many brake components are shared between the W900B and W900L models, there are some key differences. The W900B (built 1987-2009) and W900L (1987-present) have different wheelbases and frame configurations that can affect brake line routing and lengths. Most brake chambers, shoes, drums, and rotors are interchangeable between models of the same year range, but always verify your specific VIN and build date when ordering brake lines, ABS sensors, or mounting brackets. Pre-2001 models use different ABS systems than 2001+ trucks, which affects sensor compatibility.

What brake chamber sizes fit my W900, and how do I identify what I currently have?

Standard W900B/L trucks typically use Type 30 brake chambers on the front axle and Type 30 or Type 36 on the rear, depending on your GVWR and configuration. To identify your current chambers, look for stamped numbers on the chamber housing - "30" indicates a Type 30, "3030" indicates a Type 30/30 piggyback. Heavy-spec trucks may have Type 36 chambers all around. The mounting bolt pattern is standardized, but stroke length varies - 2.5" for Type 30 and 3" for Type 36. Always match your existing stroke length to maintain proper brake adjustment.

Are aftermarket brake drums and rotors as good as OEM, and what brands do you recommend?

Quality aftermarket brake drums and rotors from established manufacturers like Gunite, Webb, and Accuride meet or exceed OEM specifications and often cost 30-50% less than Kenworth genuine parts. These brands use the same casting specifications and heat treatment processes as OEM suppliers. Look for drums with wear indicators and proper cooling fin design. Avoid economy imports that may have inconsistent metallurgy. For severe-duty applications or maximum brake life, consider upgrading to centrifuse drums or composite rotors.

What's involved in converting from drum to disc brakes on my W900?

Converting to disc brakes requires a complete hub assembly replacement, new wheels with disc brake compatible bolt patterns, air disc brake calipers, rotors, and updated brake chambers. The conversion typically costs $1,200-1,800 per axle in parts alone. You'll need to verify your axle manufacturer (Dana, Meritor, etc.) and model to get the correct conversion kit. Most 2000+ W900s are pre-drilled for disc brake mounting, but earlier models may require drilling and tapping new mounting holes. Professional installation is recommended as brake balance and ABS calibration adjustments are required.

How often should I replace brake components, and what are the warning signs of wear?

Brake shoe linings should be inspected every 3 months and typically last 150,000-250,000 miles depending on application. Replace when lining thickness reaches 1/4" at the thinnest point. Drums should be measured for diameter - replace when they exceed maximum stamped diameter (typically after 2-3 brake jobs). Watch for heat checking, cracks longer than 1.5", or blue discoloration from overheating. Brake chambers should be replaced if they're leaking air, have damaged pushrods, or show corrosion on the housing. S-cam bushings typically need replacement every 300,000-500,000 miles or when shaft play exceeds 0.030".