Description LEVELING VALVE W/DUMP Part Number: FHV9990C Direct replacement (cross ref) for HV9990. Product Overview This leveling valve controls ride height by adjusting air pressure in the suspension. The “with dump” feature allows you to release air when needed, usually for loading and unloading, as well as lowering the truck. This unit replaces OEM part HV9990 and is commonly used in air ride suspension setups. What the Part Does The valve monitors the position of the suspension and adds or releases air to keep the truck sitting at the correct height. When the load changes, the valve reacts and adjusts pressure to bring things back to level. The dump function gives you manual or system-controlled ability to lower the suspension when needed. Common Problems This Part Solves When a leveling valve starts to fail, it usually shows up as: Truck sitting too high or too low Uneven ride height side to side Slow response to load changes Air leaks around the valve In some cases, the dump feature may stop working altogether. Why Replacement Matters If the truck isn’t sitting level, everything else is affected: ride quality, handling, tire wear, even driveline angles. A bad valve can also cause the system to constantly adjust, putting extra load on the air system. Replacing it restores proper ride height control and keeps the suspension working the way it should. Compatibility and Fitment This valve replaces the OEM part HV9990. Always confirm mounting style and linkage setup to ensure proper operation. Installation and Service Notes You need to mount the valve, connecting air lines, and set the linkage to the correct height position. Adjustment is key, because if it’s set wrong, the truck won’t sit correctly. Check air lines, air bags and fittings while you’re there. Leaks elsewhere can look like a valve problem. Use Case Used in suspension repairs, ride height issues, or when trucks aren’t sitting level under load. The use is varied and according to need. About Us We’re a family-owned group of Peterbilt dealerships dedicated to getting you the parts you need quickly and affordably. Whether you’re looking for Paccar OEM parts, reliable aftermarket replacements, or popular upgrades like seats and filters, we make it easy to keep your truck running and on the road. If you don’t see what you need online, just give us a call or send an email — chances are we can get it. We pride ourselves on fast service, fair prices, and being a partner you can depend on when downtime isn’t an option. FAQs Q1: What happens if the leveling valve fails? A: The truck may sit too high or too low, or not adjust properly when the load changes. That affects handling and tire wear pretty quickly. Q2: What is the dump function used for? A: It allows the suspension to be lowered, usually for loading docks or maintenance situations where height needs to be changed. Q3: Can I adjust it myself? A: You can, but it needs to be done carefully. Incorrect adjustment can throw off ride height and cause other issues. Q4: How do I know it’s the valve and not an air leak? A: Check for leaks first. If air lines and bags are good but height control is still off, the valve is likely the issue.
