Description DRAIN VALVE W/CABLE Part Number: F12105C Direct replacement (cross ref) for 12105. Product Overview The F12105C drain valve with cable is a replacement air tank drain assembly used on heavy-duty trucks to remove moisture and contaminants from the air system. Moisture buildup in air tanks is a normal part of operating an air brake system, especially in humid environments or during temperature swings. This valve provides a simple way to release collected water without having to crawl directly under the truck. This unit includes a remote pull cable, allowing the driver or technician to open the drain valve from an accessible location. What the Part Does Air brake systems compress outside air and store it in tanks for braking and other air-powered components. Along with that air comes moisture, and over time that water settles at the bottom of the tank. The drain valve allows moisture to be released before it causes problems inside the system. The pull cable design makes the process quicker and safer. Instead of reaching the valve directly on the tank, the operator simply pulls the cable to open the valve and release the buildup. Common Problems This Part Solves Drain valves live in a rough environment under the truck, so failures are fairly common over time. Road debris, rust, and constant exposure to moisture eventually take their toll. Typical issues include: Valve stuck closed, preventing tanks from draining properly Valve stuck open, causing a constant air leak Broken or seized pull cable Corrosion inside the valve body Air leaks at the drain port Why Replacement Matters Ignoring a faulty drain valve can lead to bigger problems down the road. Moisture left inside air tanks can contaminate valves, damage air dryers, and cause internal rust. In winter, trapped water can freeze and block air lines, which may affect braking performance. Compatibility and Fitment This unit is designed as a direct replacement for OEM part number 12105. The F12105C drain valve with cable is used on a variety of heavy-duty trucks equipped with manual air tank drain systems. As always, verifying the replacement number before ordering is recommended. Installation and Service Notes The old valve is removed from the tank port and replaced with the new assembly. Thread sealing compound or tape is used to prevent air leaks at the fitting. When installing the cable, make sure it is routed cleanly without sharp bends or pinch points. The cable should move freely so the valve opens fully when pulled. After installation, the air system should be pressurized and checked for leaks before putting the truck back into service. Use Case This part is commonly replaced during routine air system maintenance, especially on older trucks where corrosion has started to affect the valve. Fleets that operate in wet climates or run year-round in winter conditions tend to replace these more often. Drivers who regularly drain their tanks will also notice right away if the pull cable stops working, making this a quick and practical repair that keeps maintenance simple. 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: How often should air tanks be drained? A: Most trucks should have their air tanks drained regularly, especially if they are not equipped with a fully automatic moisture removal system. Q2: Can the pull cable wear out over time? A: The cable is exposed to road conditions, dirt, and moisture, so it can eventually rust, stretch, or seize. Q3: Is this something a shop has to install? A: Many mechanics can install a drain valve fairly quickly, but experienced drivers who do their own basic maintenance may also replace them. Q4: Do all trucks use this type of drain valve? A: Not all. Some newer systems use automatic drain valves or air dryers that handle moisture differently.
