Weather-resistant Clutch Master Cylinder for Toyota XUI3551L

CM246

Product Specifications: The following are the key parameters of this product confirmed through actual testing, used for procurement verification and technical matching:

Specifications Item	Value / Description
Part No.	XUI3545A
Internal Model	CM246
Piston Diameter	15.87 mm
Mounting Size	Φ26.7 / 60 / 90° / 2-Φ8.9 (Two Φ8.9 through holes, bolted)
Connecting Size	M10 × 1.0
Compatible System	Hydraulic Clutch System
Product Certification	ISO 9001 / TS16949

This is an aftermarket replacement part, fully compliant with Toyota original factory specifications, covering three Toyota OE reference numbers and the US DORMAN reference number CM350009, suitable for many classic Toyota pickup trucks and off-road vehicles. A problem with the master cylinder usually presents with several obvious symptoms: the pedal feels soft and yielding, like pressing cotton; the pedal lacks rebound; shifting gears is jerky or impossible. In such cases, the master cylinder must be replaced; otherwise, the vehicle will not function properly.

Vehicle Application:
XUI3551L is compatible across various vehicle models. The following are verified compatibility ranges, covering 5 classic Toyota models from 1983 to 2006:
Toyota Hilux V Pickup (Fifth Generation Hilux, Code: _N_ / KZN1_ / VZN1_)
Years: 1988 – 1999
Vehicle Characteristics: One of the world's best-selling pickup trucks, this generation of Hilux covered multiple gasoline and diesel powertrains.
Main Markets: Middle East, Africa, Southeast Asia, Australia, Latin America
Chassis Code Explanation: _N_ Universal chassis, KZN1_ Diesel version (1KZ-TE engine), VZN1_ V6 gasoline version
Toyota Hilux VI Pickup (Sixth Generation Hilux, Code: _N1_)
Years: 1994 – 2006
Vehicle Characteristics: Continuing the Hilux series Traditional pickup truck design, enhanced off-road and load-bearing performance; overlaps with the fifth generation in some markets.
Main Markets: Widely sold globally, including the Middle East, Africa, Latin America, and Southeast Asia.
Note: This product is compatible with the manual transmission version of this generation; automatic transmission versions are not applicable.
Toyota Tacoma II Pickup (Codes: RN6_ / RN5_ / LN6_ / YN6_ / YN5_ / LN5_)
Years: 1983 – 2005 (spanning a 22-year production cycle)
Vehicle Characteristics: The Tacoma is the best-selling mid-size pickup truck in the North American market, with numerous chassis codes covering multiple gasoline and diesel engine displacements.
Chassis Description: The RN series is for gasoline versions (e.g., 22R engines), the LN series is for diesel versions, and the YN series is for the 22Y gasoline version.
Main Markets: USA (including the used car aftermarket), Canada, Latin America. DORMAN CM350009 is the North American market-specific code.

Toyota 4Runner (1990-1995 models)
Vehicle characteristics: A mid-size SUV built on the Hilux platform, equipped with a manual transmission, balancing urban commuting and off-road performance.
Main markets: Primarily North America (USA and Canada), with some exports to the Middle East and Australia.
A considerable number of 4Runners from this era remain in the North American used car market, with consistently strong demand for repair parts.

Toyota Pickup (1990-1995 models)
Vehicle characteristics: The predecessor to the Tacoma, sold in the North American market as the Toyota Pickup, renamed Tacoma after 1995.
Main market: The US used car aftermarket; older vehicles but owners are enthusiastic about keeping them, resulting in stable demand for repair parts.
Core Function: The clutch master cylinder is the starting point of the manual transmission's hydraulic system; its reliability directly determines the smoothness of gear shifting and driving safety.
Hydraulic Drive: Precisely converts pedal force into hydraulic pressure, driving the entire clutch hydraulic circuit.
Sealed and Stable Pressure: Built-in precision sealing components ensure no system leakage, stable hydraulic pressure, and consistent pedal feel.
Precise Control: The 15.87mm diameter piston is precision-machined to maintain the same hydraulic ratio as the original, without affecting pedal travel or feel.
Quick Return: Spring-loaded return design allows the pedal to quickly spring back after release, adapting to the high-frequency shifting conditions of pickup trucks and engineering vehicles
Weather Resistance: The sealing material is resistant to high and low temperatures, suitable for different climates from the high temperatures of the Middle Eastern desert to the frigid conditions of North America.

Installation Notes:
The mounting holes are two Φ9 through holes (through type), with a fixing angle of 45°, perfectly matching the original installation position of the Toyota Hilux/Tacoma series.
Hydraulic Connection M10×1.0, during installation, ensure the pipe fittings and thread specifications match; avoid using fittings with different pitches.
After replacement, air must be purged from the system (bleed operation), otherwise the pedal feel will still be soft.

What problems can this product solve for overseas customers?
Toyota Hilux / Tacoma / 4Runner are among the most demanding pickup trucks and off-road vehicles globally, and also among the most competitive models in the aftermarket. Buyers typically face the following challenges when procuring these parts:
Discontinued or hard-to-find original parts for older models: Hilux V (1988-1999) and early Tacoma (1983-1995) vehicles are 25-40 years old, and Toyota OE parts are largely unavailable in some markets, creating a pressing need for repair shops to source stable replacements.
High prices for American brands like DORMAN: DORMAN CM350009 is the mainstream purchase reference in the North American market, but its price is significantly higher than direct supply from China, drastically reducing the profit margins of import distributors.
Multiple chassis versions cause confusion for buyers: The Tacoma series has as many as six chassis codes (RN6_/RN5_/LN6_, etc.), making it easy for buyers to choose the wrong one; this product is compatible with all versions, simplifying the selection process.
High verification threshold in the North American market: Entering the US aftermarket requires a DORMAN part number and credible quality assurance; this product already has DORMAN CM350009. Correspondingly, buyers can directly access North American sales channels.
High complaint rate for counterfeit and substandard parts: Pickup trucks operate under heavy loads, and low-quality clutch pumps are prone to premature oil leaks and failures, leading to constant after-sales complaints from distributors and damaging their reputation.

Q: This product has a DORMAN reference number, what does that mean?
A: DORMAN CM350009 is a commonly used parts reference number in the US auto parts market. Many US auto parts retailers and wholesalers use DORMAN numbers as a standard for procurement and inquiry. Holding this corresponding number means that buyers can directly connect with North American channels, lowering the barrier to entry into the US aftermarket.

Q: With so many chassis codes covered (RN6_/LN6_, etc.), will there be any discrepancies in installation?
A: All chassis codes marked (Tacoma's RN6_, RN5_, LN6_, YN6_, YN5_, LN5_) have been verified and share the same clutch master cylinder specifications (DIA 15.87mm, M10 interface, Φ9 through-hole mounting). Installation consistency has been confirmed. If you have any questions about a specific chassis, please provide the VIN and contact us for verification.

Q: Are the mounting holes threaded or through holes? How are they different from the previous two models?
A: This product has two Φ9 through holes (for through-hole bolt fixing), with a mounting angle of 45° and a hole spacing of 72mm. This differs from the XUI3544L-1 (M8 threaded hole / 45°) and XUI3545A (Φ8.9 through hole / 90°) in the same series. Please pay attention to the distinction when purchasing and do not mix them up.