Brake pedal goes to to floor

  • 4.0L
  • 6 CYL
  • 4WD
  • 134,000 MILES
Okay, it all started with a broken line. Replaced the line and bled all the lines. The pedal still went to the floor. So replaced master cylinder and abs pump. Bench bled master before installing. Bled system several times making sure fluid did not. Get low in reservoir. All brakes hubs and rotors are good. But pedal still goes to floor. Can pump up and hold pressure but after a few seconds of not holding the brake there is no pressure and it goes to the floor.
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have the same problem?
Tuesday, March 26th, 2019 AT 1:09 PM

1 Reply

Good afternoon,

You still have air in the system.

You need a pressure bleeder to force the fluid through the line. You can rent one at a parts store.


NOTE: Bleeding can be performed either manually or with pressure equipment. However, if pressure equipment is used, it will be necessary to hold the front brake metering valve open in order to bleed the front brakes. The valve can be held open with a tension clip tool or by hand. The front brake metering valve is located in the forward end of the combination valve. The valve stem is accessible from the same end of the valve. The stem must be either pressed inward, or held outward slightly in order to bleed the front brakes.

NOTE: It will also be necessary that a suitable size pressure tank hose adapter be available for use on the master cylinder reservoir caps.

1. Fill bleeder tank if necessary.
2. Purge air from bleeder tank and lines before proceeding.
3. Clean master cylinder reservoir and filler caps thoroughly.
4. Remove master cylinder filler caps and install pressure hose adapter in place of caps. A suitable adapter will usually be available from tank manufacturer.
5. Connect bleeder tank pressure hose to adapter.
6. Bleed master cylinder first. Bleed rear antilock valve second and front antilock valve third.
7. Bleed rear wheel brake units as described in manual bleeding procedure.
8. Bleed front wheel brake units as described in manual bleeding procedure. Have helper hold metering valve open by pressing valve stem inward slightly. Amount of valve stem movement needed to hold valve open is quite modest. Do not use excessive force.
9. Remove pressure bleeding equipment and top off master cylinder reservoir.
10. Verify firm brake pedal before moving vehicle.
11. Repeat bleeding procedure if system warning lights come on, remain on, or if pedal is still spongy.
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Tuesday, March 26th, 2019 AT 1:50 PM

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