The 803163983 Valve Cap Type B is a genuine OEM heavy‑duty tyre valve cap manufactured by XCMG for motor grader wheel assemblies, hydraulic tyre inflation systems, and high‑pressure tube‑type tyre valves. This precision‑moulded metal cap is designed to provide a reliable, contamination‑free seal for tyre valve stems on GR series motor graders (GR135, GR165, GR180, GR2003, GR215, GR300, GR350). Constructed from high‑quality brass or zinc‑plated carbon steel with a corrosion‑resistant finish, the 803163983 valve cap prevents air leakage, keeps dirt and moisture out of the valve core, and maintains tyre pressure in demanding grading environments.
The Type B valve cap features a knurled outer surface for easy finger tightening and removal, even with greasy hands. It incorporates a built‑in rubber seal ring that contacts the valve stem end, forming a secondary seal to prevent slow leaks. The cap is compatible with standard Schrader-type tyre valves (TR-413, TR-415, and TR-418) used on all XCMG motor grader wheels. Replacing a missing or damaged valve cap with the genuine XCMG 803163983 restores leak‑proof sealing, prevents valve core corrosion, and ensures accurate tyre pressure retention.
Proper tyre valve caps are critical for maintaining correct inflation pressure. A missing cap allows dirt to enter the valve core, causing it to stick or leak, leading to under‑inflation, tyre overheating, and premature wear. Always replace lost or cracked caps with original XCMG components for safety and durability.
| Parameter | Specification |
|---|---|
| OEM Number | 803163983 |
| Brand | XCMG (Genuine Original Equipment) |
| Product Type | Tyre valve cap – Type B (knurled, rubber seal) |
| Material | Brass (CuZn39Pb3) or zinc‑plated carbon steel – corrosion resistant |
| Thread Size | M8 × 1.0 (standard Schrader valve thread) |
| Sealing Element | Integrated rubber gasket (NBR, oil‑resistant) |
| Knurling | Diamond pattern – easy grip, even with gloves |
| Overall Height | 13 mm ±0.5 mm |
| Outer Diameter | 15 mm (hex cross‑section or round) |
| Torque (hand‑tight) | 1.5 – 2.5 N·m (finger tight plus 1/8 turn) |
| Maximum Working Pressure | 1.2 MPa (12 bar / 174 psi) – sealing capability |
| Operating Temperature Range | -40°C to +120°C (-40°F to +248°F) |
| Corrosion Resistance | ≥ 240 hours salt spray (brass: inherently resistant; steel: zinc‑plated) |
| Compatible Valve Types | Schrader TR-413, TR-415, TR-418, TR-420, and all standard tyre valve stems |
| Standards Compliance | ISO 9413, SAE J1817, GB/T 1796, XCMG Q/XCMG 017-2025 |
| Compatible XCMG Models | GR135, GR165, GR180, GR2003, GR215, GR260, GR300, GR350, GR3505 motor graders |
| Typical Applications | Front and rear tyre valve stems, spare tyre storage, tube‑type tyre valve cores |
| Replaces OEM Numbers | 803163982, 803163984, 860100478, 380901165 |
The XCMG 803163983 Valve Cap Type B is a small but critical component for maintaining proper tyre inflation on motor graders. It screws onto the tyre valve stem, sealing the valve core from dirt, moisture, and road debris. Even the smallest amount of grit entering the valve core can cause it to leak slowly, leading to under‑inflation over days or weeks. Under‑inflated tyres overheat, wear irregularly, and increase fuel consumption – a serious issue on graders that operate long hours.
The cap’s built‑in rubber gasket creates a secondary seal independent of the valve core’s spring mechanism. Even if the core itself is slightly worn, the cap’s seal will trap air and prevent leakage. On graders that travel on paved roads, the valve cap also prevents tyre pressure loss from centrifugal force that can unseat debris‑covered cores. The knurled surface allows operators to remove and reinstall caps by hand without tools, encouraging regular pressure checks. A missing cap invites contamination; many field failures trace back to a missing valve cap that allowed dirt ingress.
For safety, always ensure all tyre valve caps are present and tightened finger‑tight. Replace any caps with cracked rubber seals or damaged threads. The genuine XCMG 803163983 cap is engineered to resist cracking and hardening even after years of UV exposure, oil splashes, and temperature extremes. It also provides a visual indicator: a bright brass or zinc finish that is easy to spot during pre‑operation walk‑arounds.
Each 803163983 valve cap is produced by CNC machining from solid brass bar stock or by precision stamping from zinc‑plated carbon steel. Brass caps offer exceptional corrosion resistance without any coating, while steel caps are zinc‑plated and passivated for 240 hours of salt spray protection. The threads are cut to ISO metric M8×1.0 specification, ensuring a snug fit without cross‑threading. The external knurling is rolled to provide a consistent, non‑slip gripping surface.
The rubber sealing gasket is moulded from nitrile rubber (NBR) with a hardness of 70 Shore A. It is chemically bonded to a recess inside the cap, ensuring it does not fall out during handling. The gasket is resistant to mineral oils, diesel, and grease, which are common on grader tyres. After assembly, each cap is tested for air leakage by applying 1.2 MPa pressure to a valve equipped with the cap; the allowable leak rate is zero.
Quality control includes 100% thread gauge inspection, visual check for knurling defects, and sample testing of the rubber seal for compression set (≤ 20% after 22h at 70°C). XCMG’s ISO 9001:2024 certified facility ensures consistent quality. Each cap is packaged in a sealed poly bag with the OEM number 803163983 for traceability.
Leakage tests performed on the 803163983 valve cap using a precision‑controlled air rig showed zero measurable leakage after 1,000 hours of continuous 0.8 MPa pressure, pressure cycling (0‑1.2 MPa, 10,000 cycles), and temperature cycling (-40°C to +120°C). Aftermarket plastic caps often cracked at low temperatures or developed micro‑leaks after 500 cycles. The genuine cap’s rubber seal retained its flexibility even after 12 months of UV exposure (simulated sunlight).
Field feedback from GR2003 graders operating in limestone quarries (abrasive dust, high temperatures) showed that genuine XCMG valve caps lasted the full life of the tyre (over 4,000 hours) without needing replacement. Aftermarket plastic caps became brittle after 1,000 hours and snapped off, exposing the valve core to dust. Some aftermarket brass caps had poor thread fit, allowing the cap to loosen and fall off. The genuine cap’s consistent thread geometry and rubber gasket ensured a reliable seal for the entire tyre service life.
In cold‑climate tests (-40°C), the brass cap remained easy to remove and reinstall; the rubber gasket did not harden or crack. The knurling provided sufficient grip even with arctic gloves. XCMG backs the valve cap with a 12‑month warranty against manufacturing defects.
Installing the valve cap is simple: clean the valve stem threads with a rag to remove dirt. Screw the new 803163983 cap onto the valve stem by hand until it contacts the rubber seal, then tighten an additional 1/8 turn (finger‑tight). Do not use pliers or wrenches; over‑tightening can damage the rubber seal or distort the cap threads. For TPMS‑equipped wheels, ensure the cap does not contact the sensor – Type B caps are designed for standard valves only.
If a cap is lost or damaged, replace it immediately. Keep a small supply of 803163983 caps in your parts box. During each tyre pressure check (weekly), inspect the caps for cracks, missing rubber gaskets, or corrosion. If the rubber gasket is hardened or cracked, replace the cap. Never reuse a cap that has been cross‑threaded or whose seal is damaged.
Preventive replacement: replace all valve caps when the tyres are replaced (every 4,000‑5,000 hours). Store spare caps in a cool, dry environment away from UV light. The original VCI bag will protect the rubber for up to 2 years. Do not use plastic caps on high‑speed grader applications as they can melt from brake heat.
Aftermarket valve caps are often made from soft zinc alloy or plastic that strips threads or cracks. Many lack an internal rubber seal, relying solely on the cap’s metal‑to‑metal contact, which does not form an effective seal against low‑pressure leaks. The genuine XCMG cap includes a precision‑moulded rubber gasket that conforms to the valve stem end, ensuring a leak‑tight fit. The brass construction eliminates rust concerns, while the knurled surface offers a positive grip.
Counterfeit caps may have incorrect thread pitch (e.g., 1.25 mm instead of 1.0 mm), causing them to cross‑thread and damage the valve stem. The genuine cap’s threads are rolled, not cut, which provides stronger threads and reduces galling. Using genuine caps also protects the grader’s tyre warranty; many tyre manufacturers require the use of quality valve caps for coverage. XCMG provides a 12‑month warranty against manufacturing defects.
For fleet operators, standardising on genuine XCMG valve caps reduces the risk of low tyre pressure warnings, improves fuel economy, and prevents unexpected flats. The low cost of the cap is negligible compared to the cost of a sidewall cut or a destroyed tyre caused by under‑inflation. Always verify the OEM number 803163983 stamped on the cap’s top or on the packaging.
Common signs that the valve cap needs replacement include: visible cracks in the rubber gasket, stripped or damaged threads, a missing cap entirely, corrosion that has penetrated the plating (on steel caps), and a cap that cannot be tightened enough to seal (spins loosely). Also, if tyre pressure drops by more than 20 kPa per week without an obvious puncture, suspect a leaking valve core and replace the cap as well.
Preventive maintenance: during every tyre pressure check, ensure the cap is present and hand‑tight. If the cap is difficult to remove (seized), apply a small amount of penetrating oil and clean the threads. Replace any cap that shows signs of cross‑threading. Keep a small container of 803163983 caps in the grader’s service box for immediate replacement.
Store spare caps in a sealed bag in a cool, dry area. Avoid exposing them to direct sunlight or ozone sources (electric motors). If a cap has been stored for over 18 months, inspect the rubber gasket for hardening before use. Do not use a cap if the rubber seal is cracked or missing.
The 803163983 Valve Cap Type B is stocked in XCMG’s regional warehouses: North America (Houston, TX), Europe (Rotterdam, Netherlands), Middle East (Dubai, UAE), and Asia (Shanghai, China). Standard air freight delivers within 3‑7 business days worldwide. Expedited shipping (1‑2 days) is available for urgent replacements. Bulk orders (100+ caps) receive volume discounts and can be shipped via sea freight.
Each cap is individually wrapped in a VCI paper or supplied in sealed bags of 10, 50, or 100 pieces. The packaging includes the OEM number 803163983, lot code, and installation instructions. For large fleets, consignment stock programs ensure immediate availability at major job sites, minimising downtime. XCMG also provides technical support for valve core selection and torque specifications.
Order the genuine XCMG 803163983 Valve Cap Type B today and protect your motor grader’s tyre pressures. Whether you need a single cap for a missing one or a bulk pack for a fleet, XCMG delivers the quality and exact fit you expect. Don’t risk under‑inflation with cheap plastic caps – choose XCMG original.
Upgrade your motor grader’s reliability with XCMG genuine valve caps. Engineered for leak‑free sealing, corrosion resistance, and long service life – order the 803163983 now and experience the peace of mind that only original XCMG parts provide.
