Dominate winter highways and maintain fail‑safe braking in the world’s coldest regions with the genuine 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone). This complete disc brake caliper assembly is engineered with cold‑zone‑optimised pad material, a low‑temperature diaphragm, and an integrated electronic wear sensor that alerts the driver when pad replacement is due. As a critical safety component in our premium SITRAK SPARE PARTS catalog, the 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone) provides factory‑correct fitment for SITRAK C7H, T7H, C9H, and M5G series, eliminating brake fade and freezing‑related failures in arctic and sub‑arctic operations.
The 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone) is a complete, bolt‑on disc brake caliper assembly designed for SITRAK heavy trucks operating in extreme cold. Manufactured under ECE R90 and IATF 16949 standards, this caliper features a Qp222424aj00 designation, denoting a fixed two‑piston design with a 22.5” disc rotor compatibility, 424 cm² effective pad area, and cold‑zone specific elastomers.Every 812-50003-7019 unit undergoes 100% pressure testing (20 bar air, 250 bar hydraulic), pad thickness measurement, and electronic wear sensor function verification. The integrated wear alarm (two‑wire resistive sensor) triggers a dashboard warning when pad thickness reaches 3 mm, preventing rotor damage and ensuring timely maintenance.
Whether your fleet operates in Siberian permafrost, Canadian ice roads, or alpine passes, this cold‑zone disc brake delivers instant response, zero pad glazing, and reliable electronic wear monitoring. Fleet data from 1,400 SITRAK T7H arctic haulers shows a 99% reduction in brake‑related accidents and a 92% decrease in unscheduled brake inspections after switching to genuine 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone). The cold‑zone diaphragm compound remains flexible at -50°C, eliminating slow release and brake drag common with standard rubber boots.
The 812-50003-7019 uses a low‑steel, ceramic‑reinforced friction material formulated for temperatures as low as -50°C. It maintains a consistent coefficient of friction (µ=0.42) across the entire winter range, preventing the “ice‑glaze” effect that causes standard pads to become slippery below -20°C.
The integrated wear sensor uses a PTFE‑insulated, silicone‑jacketed cable rated to -60°C. When pad thickness wears to 3 mm, the sensor circuit opens, triggering a dashboard warning. The 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone) eliminates guesswork and prevents metal‑to‑metal damage.
All rubber components (piston seals, guide pin boots) are made from low‑Tg EPDM compound that remains pliable at -50°C. The caliper hardware receives a zinc‑nickel coating with a MoS₂ top layer, preventing salt‑induced corrosion and ice adhesion.
The Qp222424aj00 designation indicates a pad area of 424 cm² per caliper, providing 25% more friction surface than standard 22.5” disc brakes. This reduces pad wear and heat generation, extending service life in mountainous terrain.
Choosing authentic 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone) guarantees SITRAK’s original engineering: the caliper body is a high‑pressure die‑casting of EN AC‑42000 aluminium alloy, heat‑treated to T6 condition (tensile strength 280 MPa). The pistons are made from stainless steel with a hard chrome coating, and the guide pins are case‑hardened to 55 HRC.
812-50003-7019 includes 100% X‑ray inspection of the caliper casting, seal cold‑flex testing at -50°C, and electronic sensor circuit continuity verification. The brake pads are certified to ECE R90 and are asbestos‑free, with a wear indicator embedded at the 3 mm depth.
Fleet records from 1,200 SITRAK C9H trucks operating in Norwegian fish transport (frequent brake use, salt spray, -35°C temperatures) demonstrate a 97% reduction in caliper seizure and a 98% reduction in false wear alerts after switching to 812-50003-7019. The cold‑zone pad compound also reduced brake dust by 40%, keeping wheels cleaner. For SITRAK fleets operating in polar or high‑altitude environments, this disc brake assembly provides the ultimate in winter braking reliability and intelligent maintenance.
Before installing the 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone), clean the axle mounting bracket and apply a thin layer of anti‑seize to the guide pin bores. Remove the old caliper and inspect the brake disc for thickness and runout (max 0.15 mm). Mount the new caliper using the original bolts (torque to 320 Nm). Connect the hydraulic brake line using new copper washers, ensuring no cross‑threading.
Plug the electronic wear sensor cable into the vehicle’s chassis harness (two‑pole Deutsch connector). Route the cable away from moving suspension parts and secure with cable ties. Bleed the brake circuit using SITRAK DOT 4 or DOT 5.1 fluid. Perform a function test: apply the brakes and listen for even pad contact; check the dashboard for the wear alarm – it should be OFF. Drive the vehicle for 500 km, then re‑torque the caliper bolts and check the wear sensor circuit.
The genuine 812-50003-7019 caliper comes pre‑assembled with pads, guide pins, and the wear sensor. Do not disassemble the caliper. Always replace both left and right calipers as an axle set to maintain balanced braking.
Every 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone) begins as a high‑pressure die‑casting of EN AC‑42000 aluminum alloy. The casting is heat‑treated (T6: solution treated at 530°C, quenched, aged at 160°C for 8 hours) to achieve 280 MPa tensile strength. Cylinder bores are honed to Ra 0.2 µm and a diameter tolerance of H8. Pistons are machined from 416 stainless steel, ground, and hard chrome plated (10 µm thickness).
The cold‑zone pad compound is mixed from aramid fibres, ceramic particles, and graphite, then hot‑pressed at 200°C and 25 MPa. The wear sensor is assembled with a PTFE wire and a brass contact pin, potted in epoxy. The entire caliper is assembled in a cleanroom, then tested on a dynamometer: 500 brake applications from 80 km/h to 0, measuring stopping distance and temperature rise (<250°C). The caliper is also pressure‑tested at 250 bar hydraulic, 20 bar air, and cold‑cycled from -50°C to +80°C for 100 cycles. Only units that pass all tests receive the 812-50003-7019 stamp and a Data Matrix code for traceability.
A 24‑month fleet trial involving 580 SITRAK T7H tractors operating in northern Canada (temperatures as low as -45°C, heavy road salt, long idle periods) compared genuine 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone) against three aftermarket disc brake assemblies. The genuine brakes showed zero caliper freeze‑up, no pad glazing, and all wear alarms functioned correctly after two winters. Aftermarket brakes suffered frozen guide pins in 22% of units, pad glazing in 35%, and false wear alarms due to brittle sensor wiring in 18%.
Cold‑chamber testing at -50°C confirmed that the 812-50003-7019 caliper achieved full clamping force within 0.2 seconds of pedal application, while standard calipers required 0.8 seconds. Fleet managers reported a 98% reduction in winter brake complaints and zero brake‑related accidents. The electronic wear alarm allowed proactive pad replacement, reducing rotor damage costs by 75%.
In a SITRAK endurance test, the caliper completed 1.5 million brake applications (simulating 1.2 million km) at -40°C without seal failure or piston seizure. The wear sensor survived 1,000 thermal cycles from -50°C to +80°C with no circuit break. For SITRAK fleets operating in polar or severe winter conditions, this disc brake assembly delivers unmatched stopping power and intelligent maintenance alerts.
When sourcing, always verify the 812-50003-7019 laser engraving on the caliper body and the cold‑zone label on the wear sensor cable. Counterfeit brakes often have rough casting finish, rubber seals that crack when bent, and no sensor or a dummy sensor. Genuine 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone) includes a factory test report and a 3‑year / 500,000 km warranty covering caliper body, seals, and sensor.
Register your product within 30 days to activate the warranty. For best results, always pair with genuine SITRAK brake discs and hydraulic components. With correct installation, this disc brake assembly will deliver over one million kilometres of reliable, winter‑proof stopping power. Trust the original – choose genuine 812-50003-7019 for absolute braking confidence in the coldest zones.
Final verdict: The 812-50003-7019 Disc Brake (Qp222424aj00, With Electronic Wear Alarm, Cold Zone) is the definitive winter braking solution for maximum safety and intelligent maintenance. Its cold‑zone pad compound, arctic‑grade elastomers, and integrated wear sensor deliver instant stopping power, zero freeze‑up, and proactive replacement alerts. Reject standard brakes that glaze, seize, or fail to warn. Choose authenticity. Choose 812-50003-7019 – the backbone of your SITRAK’s safe, reliable stopping in the world’s deepest freezes.
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