No truck works without a functional braking system, and the dash brake valve is one of the most important pieces in the puzzle. This valve controls the air supply for the parking and trailer brakes, so when it starts acting up, you'll notice difficulty in applying or releasing the brakes. You can’t ignore this and you are probably here because you need some help, and we’re coming in ‘clutch’ to save the day (pun intended).
Tools and Parts You’ll Need:
- New dash brake valve
- Socket set
- Line wrenches
- Screwdrivers
- Torque wrench
- Air hose plug
1. Prepare the truck
Before you get started, make sure the truck is parked and secured. It sounds trivial but it’s important. Also, it would be much safer if you disconnect the battery to avoid any power surges.
2. Locate the dash brake valve
The dash brake valve is typically located behind the dashboard, near the center console. Remove the dashboard panel to access it using a screwdriver.
3. Drain the air tanks
Pump the brakes until the air pressure gauges go to 0psi or by opening the drain valves on your air tanks located under the driver-side steps.
4. Disconnect the air lines
Now, disconnect the air lines attached to the valve using your line wrench. You may have to deal with five or six air connections. If there's an "exhaust" air hose, you may not need it for newer replacements, so you can safely discard it.
5. Remove the old valve
After you disconnect the air lines, use your socket set to remove the bolts that hold the valve in place. Be careful when handling the old unit, as air can sometimes still be trapped inside.
6. Install the new dash brake valve
Put the new dash brake valve in the same location, bolt it down with your socket set, and make sure you torque the bolts well to avoid any leaks or issues later.
7. Reconnect the air lines
Reconnect the air lines to the new valve and tighten them securely. Replace any worn-out fittings if necessary and double-check that the lines are properly seated to avoid air leaks.
8. Test the brakes
Make sure you reconnect the battery. Test the parking and trailer brakes by engaging and releasing them a few times. You should hear the familiar hissing sound of air movement, and the brakes should feel responsive. If the system seems sluggish or you hear any unusual sounds, recheck the air lines and fittings.
Conclusion
Doing a dash brake valve replacement by yourself is not supposed to be difficult, but at the same time, it is crucial that you dedicate your full focus. As we said in the beginning, a faulty braking system can turn really bad quickly. Now your Volvo VNL should feel brand new. Congrats and keep hauling!
