Q: Changed brake master cylinder, bled 10 times, and the pedal is soft The rear brakes are not locked but close. Truck now running rough.

asked by on

I changed my brake master cylinder on a newly purchased 1997 4runner due to a soft pedal (no leaks) and bled the brakes 10 times. I bench-bled the master cylinder and had no issues with the install. Saw a video on YouTube that said to run the vehicle to speed and jam on the brakes, thus pushing any air down so it could be bled. Did this in drive and reverse. Brakes made a strange noise when jamming on the brakes in reverse. Now the brakes aren't locked, but not free and the truck is running rough. No issue with the engine idle or rear brakes prior to replacement of MC. Bled the rears and they released. Drove to the store and after backing out they began to draqg in drive and truck is now running rough. HELP!

My car has 225000 miles.
My car has an automatic transmission.

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. Changed brake master cylinder, bled 10 times, and the pedal is soft The rear brakes are not locked but close. Truck now running rough.

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: my 4runner has no power pulling hills?

Hi Marsha. Has the timing belt been recently serviced? If so, did the concern start after this service? The timing belt may be incorrectly set. However, if the timing belt has not been recently serviced there are other possible reasons...

Q: How do I know when my wheel bearings are going out?

Your accessory and serpentine belts may squeak or chirp a bit in cold weather due to the fact that the belts become brittle and less pliable during the cold weather months. When they go from a cold stand still to...

Q: Is bleeding brakes needed after pads replacement?

It really depends on how you deal with the system. Some guys are worried about damaging the brake master cylinder. So they open the bleeder valve on the brakes and then squeeze the caliper back in when they change the...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...