Skip the auto shop - Our mechanics make house calls

Q: Replaced master cylinder and brakes still going to the floor and not working. Bed both master cylinders and each wheel.

asked by on

Replaced master cylinder and brakes still going to the floor and not working. Bed both master cylinders and each wheel.

My car has an automatic transmission.

A: Hi, thanks for writing in. At first it soun...

Hi, thanks for writing in. At first it sounds like you may still have air in the system. The other option is that you may have a leak somewhere. Try to bleed the master cylinder and the lines again. The new master cylinder must be bench bled off of the vehicle exactly as the instructions say. The other problem could be a leak on the system. You should check for drips, puddles forming, or other signs of leaking brake fluid. Worst case scenario, the replacement master cylinder may have come to you faulty in the first place. This is rare but can happen, especially when it comes to remanufactured master cylinders. New ones typically don't have issues. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Truck with P0707 code - 2011 Isuzu NQR

Hello - if you are still getting the P0707 code after replacing the range sensor switch, either the new sensor switch is out of adjustment still, or the wiring/connection to that sensor is malfunctioning. I would recommend a transmission selector...

Q: Headlight Issue

Hello. The daytime running lights are not supposed to function at the same time as the headlights. The daytime running lights are only supposed to come on during the day, to provide additional visibility for daytime driving, independently of the...

Q: Brakes will not decelerate and steering wheel seized

This issue that would need to be inspected firsthand. In the case of such a catastrophic event, I would guess some Diagnostic Trouble Codes (DTCs) would be stored. Retrieving these codes is the first step in the diagnostic process. It...

Related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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.