The Double H valve assembly is the intelligent command centre of your automated manual transmission, precisely directing pneumatic pressure to execute smooth, rapid gear changes. The AZ220325000007 Double H valve assembly from HOWO is engineered to deliver instantaneous response, exceptional reliability, and a perfect factory fit, ensuring that your AMT shifts with the precision and consistency that modern heavy-duty logistics demand. As a critical Howo/Sitrak truck parts component, this valve assembly is manufactured from high-grade aluminium with precision‑machined spools and O‑ring seals, providing outstanding resistance to pressure spikes, temperature extremes, and contamination. Whether you are troubleshooting a shifting fault or performing a preventive overhaul, the AZ220325000007 guarantees factory‑spec flow characteristics, leak‑free operation, and extended transmission life – making it the trusted choice for professional workshops and fleet operators worldwide.
The Double H valve assembly is the heart of the pneumatic shift system in HOWO automated manual transmissions (AMT), governing the selection and engagement of gears with millisecond precision. The AZ220325000007 is specifically designed to interface seamlessly with the transmission control unit (TCU), translating electrical signals into precise air pressure pulses that actuate the shift forks. A worn or sticking valve can cause delayed shifts, harsh engagement, and even complete loss of gear selection – a serious safety and productivity risk. HOWO has engineered this assembly with hardened steel spools, low‑friction O‑rings, and a corrosion‑resistant aluminium body that withstands the rigours of continuous duty. Its integrated solenoid valves are optimised for fast response, while the internal porting ensures minimal pressure drop, delivering crisp, reliable shifts every time. With the AZ220325000007, you restore the original shifting quality, reduce driver fatigue, and protect your transmission from unnecessary wear.
Instant Response
Millisecond Shifts
Leak‑Proof
Precision Seals
OEM Grade
Genuine HOWO
High Flow
Optimised Porting
Comprehensive engineering data is vital for correct selection and installation. The AZ220325000007 is manufactured to stringent OEM tolerances, guaranteeing a seamless replacement for your HOWO AMT system.
| Parameter | Specification | Detail |
|---|---|---|
| OEM Number | AZ220325000007 | Exact Match |
| Part Name | Double H valve assembly | HOWO Genuine |
| Brand | HOWO | Original Equipment |
| Application | HOWO T7H / A7 / AMT transmissions | HW19710 / HW25712 series |
| Supply Voltage | 24V DC | PWM controlled |
| Operating Pressure | 6–10 bar (87–145 psi) | Regulated air supply |
| Number of Solenoids | 2 (Double H configuration) | Integrated PCB |
| Connector Type | Deutsch 10‑pin | Waterproof IP67 |
| Response Time | ≤ 20 ms | Fast actuation |
| Weight | 1.2 kg | Compact |
| Warranty | 12 Months | Manufacturer Guarantee |
The AZ220325000007 is a masterpiece of pneumatic and electronic integration. Its housing is precision‑cast from lightweight, corrosion‑resistant aluminium alloy, with all internal passages machined to optimise airflow and minimise turbulence. The spools are manufactured from hardened stainless steel, ground to a mirror finish to reduce friction and wear, ensuring consistent valve operation over millions of cycles. Each solenoid is carefully matched to provide precise magnetic force, delivering reliable switching even under fluctuating voltage conditions. The integrated circuit board includes transient voltage suppression and diagnostic feedback, allowing the TCU to monitor valve health and detect faults early. O‑rings are made from high‑grade fluorocarbon rubber, compatible with all common transmission fluids and operating temperatures. Every assembly is function‑tested on dedicated test rigs, simulating real‑world shift patterns to guarantee flawless operation. This meticulous engineering translates into a valve assembly that provides thousands of trouble‑free shifts, enhancing driver satisfaction and reducing unscheduled maintenance.
The AZ220325000007 is specifically designed for HOWO automated manual transmissions (AMT), particularly the HW19710 and HW25712 series used in T7H, A7, and other heavy‑duty models. It mounts directly onto the transmission housing or on a dedicated bracket, connecting to the shift actuators via pneumatic lines. Its electrical connector and pin‑out match the original TCU wiring, allowing plug‑and‑play installation without adapter harnesses. This valve assembly is also compatible with many Sinotruk and other commercial vehicles that share the same AMT architecture. To confirm fitment, always cross‑reference the OEM number on your existing assembly with AZ220325000007. If they match, this component will integrate seamlessly. Keeping this valve in your inventory ensures rapid repairs when shift problems arise, minimising downtime and keeping your fleet on the move.
HOWO T7H
Primary Fitment
HOWO A7
Also Compatible
HW19710/25712 AMT
Direct Mount
Plug & Play
No Adapters
Replacing a sluggish or leaking valve assembly with the AZ220325000007 restores the shift quality of your AMT. The improved flow characteristics and fast solenoid response reduce shift times, resulting in smoother acceleration, less drivetrain shock, and improved fuel efficiency due to reduced torque interruption. The precise pressure control also reduces wear on synchronizers and shift forks, extending transmission life. Drivers will appreciate the consistent, predictable shifting, especially in stop‑and‑go traffic or during heavy‑loaded starts. For fleet managers, the reduced incidence of fault codes minimises diagnostic time and keeps trucks on the road. By investing in the AZ220325000007, you ensure that your HOWO AMT performs as intended, delivering the driving experience and reliability that modern logistics demand.
Installing the AZ220325000007 Double H valve assembly is a moderate‑complexity task. Begin by safely parking the vehicle, engaging the parking brake, and disconnecting the battery. Remove the old valve assembly by unplugging the electrical connector, disconnecting the pneumatic lines (marking their positions), and removing the mounting bolts. Clean the mounting surface and inspect the pneumatic fittings for debris or damage. Install the new assembly using new O‑rings or seals if supplied. Torque the mounting bolts to specification. Reconnect the pneumatic lines according to your markings, ensuring no cross‑connection. Plug in the electrical connector and secure it with the locking clip. Reconnect the battery and perform a diagnostic system check using the vehicle’s diagnostic tool to verify communication and valve function. If shifting is not smooth, check for air supply pressure and purge any moisture from the system. With proper installation, the AZ220325000007 will provide years of reliable service.
Pro Tip: Always replace the desiccant filter in the air supply system when replacing the valve assembly. Moisture and contaminants are the leading causes of valve sticking. The AZ220325000007 is designed for clean, dry air – a clean supply ensures optimal performance.
Genuine HOWO components are engineered to the highest standards, and the AZ220325000007 Double H valve assembly is no exception. Aftermarket valves often use substandard solenoids, inferior aluminium alloys, or inaccurate porting, leading to sluggish shifts, erratic behaviour, or premature failure. HOWO’s assembly is manufactured using the same materials and processes as the original equipment, guaranteeing a perfect fit and reliable performance. By choosing the AZ220325000007, you benefit from HOWO’s rigorous environmental testing, which includes thermal cycling, vibration, and salt spray tests. This ensures that the valve assembly can withstand the demanding conditions of over‑the‑road trucking. Moreover, genuine parts are backed by a comprehensive warranty and supported by HOWO’s global network of technical experts, giving you confidence in your purchase.
OEM Authentic
Factory Quality
Long Service
Extended Life
Global Standard
Trusted Worldwide
Q: Which transmissions use the AZ220325000007?
A: It is used in HOWO HW19710 and HW25712 automated manual transmissions (AMT) found in T7H, A7, and similar models.
Q: What are the symptoms of a failing Double H valve?
A: Delayed or harsh shifts, failure to select a gear, intermittent transmission fault warnings, and erratic up/down shifts are common indicators.
Q: Can I install this myself?
A: While possible for experienced technicians, it is recommended to have a certified mechanic perform the installation and subsequent TCU calibration to ensure proper adaptation.
Q: How do I confirm the correct part?
A: Check the OEM number on your existing valve assembly. If it matches AZ220325000007, this is the correct replacement. Consult your vehicle’s service bulletin for additional confirmation.
Order your AZ220325000007 Double H Valve Assembly today! Explore our full inventory of genuine HOWO and Sinotruk AMT components at Howo/Sitrak truck parts and ensure your transmission shifts with factory precision.
The AZ220325000007 Double H Valve Assembly from HOWO is a testament to advanced pneumatic control and rugged construction. By choosing this genuine component, you restore the intelligent shifting capabilities of your automated transmission, reducing driver workload and protecting your drivetrain from unnecessary stress. Whether you are a professional fleet manager or an independent mechanic, this valve assembly offers the precision and durability required for modern heavy‑duty trucking. Trust HOWO – the benchmark for excellence in heavy‑duty truck components – and experience the difference that genuine quality makes.
We are a heavy-duty truck parts store. Please leave your contact information and inquiries. We will respond within 12 hours.
