Clutch master cylinder with double bolt mounting for Toyota Hilux XUI3554A

CM246

OE Number	Applicable Instructions
31410-12190	Toyota Original Standard Part Numbers, More Commonly Used Replacement Parts
31410-12191	Variation Part Numbers in the Same Series, Same Installation Dimensions
31410-12210	Later Version Replacement Part Numbers, Used in Some Markets
31410-16021	Part Number for Toyota Commercial Vehicles
31410-16022	Derivative Part Numbers in the Same Series
31410-16023	Applicable to Some Hilux and Corolla Models

Parameter Item	Specification Value	Remarks
Product Model	XUI3554A	Two Bolts Version
Inner Diameter (DIA)	15.87mm (5/8 inch)	Standard Toyota Hilux specification
Mounting Dimensions	Φ26.7 / 72 / 45° / 2-M8×1.25	Double bolt fixing, hole diameter Φ26.7mm, mounting angle 45°
Connecting Thread	M10 × 1.0	Standard hydraulic line connection specification
Piston Material	Aluminum alloy + rubber seals	Main cup + auxiliary cup double seal
Applicable Models	Toyota Hilux LN36/LN40 Pick Up (1983 and later)	—
Compatible Engines	L / 2L / 2L-T Diesel Series 2.0L–2.4L Naturally Aspirated/Turbocharged	—

This master cylinder with a two-bolt mounting structure is designed specifically for Toyota Hilux LN36 and LN40 pickup trucks manufactured in 1983 and later. It features a cast iron body and an inner diameter of 5/8 inches (15.87mm), and is the standard specification for Toyota's L-series diesel engine (2L/3L) models. Compared to single-bolt or boltless versions, the two-bolt structure offers greater installation stability under off-road and heavy-duty conditions, effectively resisting the risk of loosening caused by engine compartment vibrations.

Specific Applications
Compatible Models
Toyota Hilux LN36 Pick Up — 1981-1984 models, equipped with L-series 2.0L/2.2L diesel engines, standard configuration for the third-generation Hilux pickup truck.
Toyota Hilux LN40 Pick Up — 1980-1983 models, also equipped with L-series diesel engines, targeting the commercial transport and agricultural operation markets.
Toyota Hilux LN46 — A derivative model for some years, sharing the clutch hydraulic system architecture with the LN36/LN40.
Toyota Corolla AE92/EE90/CE90 — Some market versions use the same clutch master cylinder with OE number 31410-12190.
Toyota Dyna — Some years' versions of light commercial trucks.
Engine Matching
L-series diesel engines: 2.0L, 2.2L, 2.4L 2L-T (Naturally Aspirated and Turbocharged Versions)
Applicable Scenarios: Agricultural Transportation, Mining Operations, Construction Sites, Off-Road Modification, Classic Car Restoration

Core Functions: The clutch master cylinder is the starting control unit of the hydraulic clutch system in manual transmission vehicles. The core functions of the XUI3554A include:
Hydraulic Pressure Generation: Converts the mechanical force of the driver's pedal into hydraulic oil pressure, which is then transmitted to the clutch slave cylinders through the pipeline.
Precise Stroke Control: A standard 15.87mm inner diameter design ensures a linear correspondence between pedal travel and clutch disengagement travel.
Sealing and Pressure Maintenance: Built-in double sealing structure with main and auxiliary piston cups prevents hydraulic oil leakage and maintains system pressure stability.
Double Bolt Vibration-Resistant Fixing: M8×1.25 double bolt installation method ensures firm positioning under pickup truck off-road and heavy-duty conditions.
Buffer Seat Design: Note whether the connector is equipped with a buffer seat, as this design directly affects installation compatibility and pipeline connection sealing.

Important Note: When purchasing, please confirm whether the connector includes a buffer seat. Different OE parts may have different buffer seat designs, directly affecting installation compatibility. It is recommended to check the actual vehicle used part or provide the VIN code for confirmation before ordering.

Customer Pain Points Solved
Original parts discontinued or with lead times of 3-6 months: In-stock/near-in-stock supply, delivery time 45-50 days, safety stock plan supported.
Aftermarket parts quality varies greatly, with frequent sealing leaks: ISO9001/TS16949 quality system control, 100% sealing test before shipment.
Single-bolt version loosens and leaks oil under off-road conditions: Double-bolt M8×1.25 structure, improved vibration resistance, reduced after-sales claims.
Different OE numbers correspond to different buffer seats, high return rate for incorrect purchases: Detailed number conversion table and buffer seat confirmation guide provided, custom samples supported.

Q1: How do I determine if my vehicle needs the version with or without a buffer seat?
A: The buffer seat is located at the hydraulic line connection end, used to absorb line vibration and enhance sealing. Please remove the old part and take photos to confirm whether the plug end has a rubber/plastic buffer pad structure, or provide the vehicle VIN code and the old part's OE number, and we will assist in verification.

Q2: Is this master cylinder compatible with right-hand drive (RHD) and left-hand drive (LHD) vehicles?
A: The clutch master cylinder is a universal component of the hydraulic system and is not differentiated by left or right steering wheel. It can be installed as long as the vehicle model and OE part number match. Both RHD and LHD versions of the Hilux LN36/LN40 are compatible.