Q: Brakes lose pressure sometimes

asked by on

Sometimes when hitting the breaks the pedal will go to the floor. I pump them and the pressure back up. Sometimes its hard, sometimes squishy. When the pressure is there the pedal does not sink.

Your brake issues can be singular or possible twofold. When the brake pedal goes too low, or to the floor, but firms up if pumped, that indicates that the primary seal in the master cylinder has failed. Pumping the brakes allows the secondary seal to produce some pressure. By that alone, I suggest replacing the brake master cylinder.

A ’hard" brake pedal can indicate a vacuum issue with the power brake booster. The booster itself may be failing - possible if brake fluid is leaking from the master cylinder into the booster and will not be a visible leak until the master cylinder is removed from the booster. Also, the booster may not be receiving the proper amount of vacuum from the engine. This can be due to the vacuum hose being partially collapsed internally, or the vacuum check valve not functioning properly.

I would recommend the master cylinder replacement - which would include bleeding the entire brake system. If the pedal continues to feel "hard" after replacement, a certified technician can further inspect the system to determine why the brake pedal is hard.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Brakes lose pressure sometimes

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: How do I know if the fuel pump is bad?

Hi, thanks for writing in. You will need to check the fuel pressure on the fuel pressure port on the engine fuel rail. The pump should be producing at least 56 to 62 psi for SFI engine. If pressure is...

Q: Q: Air conditioner

You need to take it to a different mechanic to have a diagnosis. You either leaked out the refrigerant or the system was overcharged. Have the pressures checked. The sealer will not seal a leak in an evaporator or a...

Q: I Had a diagnostic test for Ford escort. What can I do about the Mass Air Flow sensor?

Hi there. You can remove and clean the Mass Air Flow sensor with an electrical cleaner that is non chlorinated. If the sensor is cleaned out and the light is still on, check the intake hoses from the sensor to...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.