This month’s Pop Quiz takes a look at master cylinders and braking systems.
Chose True or False to the following statements.
If False, write in why the statement is not accurate.
1) The modern master cylinder evolved from the single-piston types popularly introduced in the 1930s, to the modern quad-piston, dual braking system cylinders in use today.
True or False
2) Master cylinders intended for drum brake use contain one or more residual pressure check valves that maintain a slight pressure in the system.
True or False
3) The residual pressure applies tension to the wheel cylinder linkage in the drum brakes and in order to keep the wheel cylinder piston cups away from the cylinder bores.
True or False
4) The cylinder also incorporates a “depletion” port that is located immediately ahead of the lip of each primary and secondary piston seal or cup. The depletion port is designed to bleed air bubbles from the cylinder bore into the cylinder reservoir.
True or False
5 ) During the 1980s, a quick take-up device was incorporated in some master cylinders to quickly take up the wide brake pad-to-brake rotor clearances existing on some braking systems.
True or False
6) Because some modern anti-lock braking systems might require a bi-directional scan tool to bleed the systems, it’s always best to inject air into the system by bench-bleeding the master cylinder before installation.
True or False
7 ) The master cylinder bore incorporates a “breather” port located behind the piston cup, which allows brake fluid to flow into the cylinder as the brake pedal is depressed.
True or False
8) Dual master cylinders are configured to operate two separate braking systems. The brake booster push rod engages the primary piston first. The secondary piston is normally engaged by hydraulic pressure generated by the primary piston.
True or False
9) A hydraulic pressure failure-warning switch monitors the primary and secondary systems for loss of air pressure.
True or False
10) Most modern cylinders incorporate a semi-transparent fluid reservoir that allows fluid level to be inspected without exposing the brake fluid to moisture and dirt by removing the sealed filler cap.
True or False
Solution below…
ANSWER KEY:
1) The modern master cylinder evolved from the single-piston types popularly introduced in the 1930s, to the modern quad-piston, dual braking system cylinders in use today.
False: Today’s system is a dual-piston, not quad-piston system.
2) Master cylinders intended for drum brake use contain one or more residual pressure check valves that maintain a slight pressure in the system.
True
3) The residual pressure applies tension to the wheel cylinder linkage in the drum brakes in order to keep the wheel cylinder piston cups away from the cylinder bores.
False: This residual pressure applies tension to the wheel cylinder linkage in the drum brakes and keeps the wheel cylinder piston cups expanded against the cylinder bores.
4) The cylinder also incorporates a “depletion” port that is located immediately ahead of the lip of each primary and secondary piston seal or cup. The depletion port is designed to bleed air bubbles from the cylinder bore into the cylinder reservoir.
False: The port is called a compensation or compensating port, not depletion.
5) During the 1980s, a quick take-up device was incorporated in some master cylinders to quickly take up the wide brake pad-to-brake rotor clearances existing on some braking systems.
True
6) Because some modern anti-lock braking systems might require a bi-directional scan tool to bleed the systems, it’s always best to inject air into the system by bench-bleeding the master cylinder before installation.
False: you should avoid injecting air into these systems.
7) The master cylinder bore incorporates a “breather” port located behind the piston cup, which allows brake fluid to flow into the cylinder as the brake pedal is depressed.
True
8) Dual master cylinders are configured to operate two separate braking systems. The brake booster push rod engages the primary piston first. The secondary piston is normally engaged by hydraulic pressure generated by the primary piston.
True
9) A hydraulic pressure failure-warning switch monitors the primary and secondary systems for loss of air pressure.
False: it monitors loss of hydraulic pressure
10) Most modern cylinders incorporate a semi-transparent fluid reservoir that allows fluid level to be inspected without exposing the brake fluid to moisture and dirt by removing the sealed filler cap.
True
