What Aspects Should Be Noted When Disassembling The Old Master Pump

safety precautions, component protection and appropriate operating procedures are required when removing the old brake master cylinder. Specific caveats and points are as follows:
I. Safety Precautions and Preparation
* Vehicle security and protection
* Park the vehicle on a smooth, solid surface. Start the handbrake. When lifting a vehicle with a jack, make sure to use a safety bracket,such as a a trestle, to support the body to prevent the jack from failing and causing the vehicle to tip over.
* Wear protective gloves and goggles to prevent brake fluid from coming into contact with your skin or eyes (brake fluid is toxic and corrosive; if spilled, rinse immediately).
* Tools and Materials Preparation
* Prepare suitable wrenches (such as hose nut wrenches, socket wrenches), screwdrivers, syringes, brake fluid containers, hoses, markers, etc.
* Make sure the tool is clean and free of impurities to avoid scratching components during operation.
ii. Discharge and collection of Brake Fluid Draining
• Drains Brake Fluid
* Method 1: Use a syringe or hose connected to a brake clamp bleed valve. Slowly release the valve, then press the brake pedal, releasing the brake fluid into the container.
Method 2: Loosen the nut connecting the master cylinder to the brake hose to allow brake fluid to flow naturally (collect it in a container beforehand).
Note: Drain slowly to avoid splashing brake fluid; brake brake fluid from different wheels may mix, so it should be collected and disposed of properly.
Marking and sorting: Marks discharge brake fluid (e.g. "front wheel left", "back wheel right") for subsequent inspection or recovery (if not contaminated).
Waste brake fluid must be disposed of in accordance with environmental protection requirements and not dumped at will.
III. Removal Related Components
Disconnect electrical connection: If master cylinder has an integrated brake fluid level switch or sensor, disconnect its harness connector first to avoid straining the wire.
Tip: Give the connector clip a gentle squeeze and pull it out; avoid excessive force that could damage the connector.
Disconnect Brake Hose: Use hose nut wrench to loosen nut connecting master cylinder to brake hose. Make sure nut and hose rotate in sync to avoid stripping the thread.
KEY OPERATIONS: Before removal, mark the connection between the brake hoses and the master cylinder to facilitate calibration during installation.
After loosening the nut, wrap a soft cloth around the hose openings to prevent impurities from entering.
Remove fastening bolts
Remove the retaining bolt (usually 2-3 bolts) of the brake master cylinder using a socket wrench. Note the loosening sequence (e.g. diagonal relaxation) to avoid stress concentration.
NOTE: If bolts are rusty, spray with a loosening agent (e.g. WD-40) and remove later.
IV. INTRODUCTION Component Protection and inspection
Protect the Brake Hose
Remove the main cylinder and wrap the brake hose in a soft cloth or plastic bag to prevent dust or impurities from entering.
If the hose needs to be temporarily removed, secure it to the unmoving part of the body with cable ties or tape to prevent impact.
Check Related Components
Check that brake booster (such as vacuum booster) interface is well sealed. Replace damaged components.
Check the brake main cylinder mounting bracket for deformation or wear. Repair or replace if necessary.
V. Special precautions for selected models of vehicles
* ** Type with ABS:** Before removing, turn off the power to the ABS pump (for example, removing the fuse) to avoid triggering ABS fault codes during use.
**Some types of ABS pumps are combined with the main cylinder; removal must be carried out step by step in accordance with instruction manual to avoid damage to electronic components.
* ** Model electronic parking brake:** If master cylinder is connected to the electronic parking brake module, the parking brake cable must be released using a diagnostic tool before removing the master cylinder.
**Refer to the vehicle's repair manual for specific steps prior to operation.
VI. INTRODUCTION Operational Prohibitions and common Mistakess
* * _Do not forcibly remove: _ ** Avoid hitting the main cylinder or brake lines with a hammer to prevent components from deforming or breaking.
**If the nut is rusty, don't open it too hard, deal with the rust first or seek professional assistance.
**Avoid Mixing Brake Fluid:** If you need to add brake fluid during removal, use the same type of fluid as the original (e.g., DOT3, DOT4) and do not mix different types of brake fluid.
** Preventing air from entering:** When disconnecting brake lines, minimize exposure time and prevent air from entering the braking system (re-bloodletting is afterward required).