Toyota Brake Master Cylinder
Toyota Master Brake Cylinder The brake master cylinder provides hydraulic pressure to activate the brakes when you push on the brake pedal.
It can fail in a number of ways. If it is losing the ability to generate and hold hydraulic pressure, the brake pedal may either intermittently or consistently go much lower to the floor than is normal while at the same time you experience a significant loss of stopping ability.
This can happen even though the brake fluid reservoir is full of brake fluid.
It can also fail by means of leaking the hydraulic fluid out externally. Usually when this happens, the brakes continue to operate normally until enough fluid is lost that the hydraulic system gets air in it, at which time the brake pedal gets soft and spongy feeling, and again, you experience significant loss of stopping ability.
If someone were to misadjust it with insufficient freeplay, the brake master cylinder wouldn’t be able to properly release the brakes. In this case, the pedal gets harder and harder, and as the brakes get hot and heat up the brake fluid, it expands and the brakes begin to self-activate even more till the vehicle eventually can’t move any further. Incorrect fluid substituted for brake hydraulic fluid can swell the inner seals and result in the same effect.
The brake master cylinder is critical to your safety. If it should fail completely, you would have no brakes whatsoever.
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