My brakes are still going straight to the floor

GUS GUS

MEMBER
2005 CHRYSLER TOWN AND COUNTRY
3.3L
6 CYL
2WD
AUTOMATIC
140,000 MILES

I am having issues with the brakes on my van. I have a leak somewhere. The lines are not leaking, nor is it leaking at the brake pads. So I went and replaced the master cylinder and my brakes are still going straight to the floor. Now when the car is off I can pump the brakes and make the firm, but so soon as I turn the car on the brake pedal goes straight to the floor.

1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning,

You have air in the system.

I would suggest pressure bleeding the system. The vacuum and 2 person bleeding does not get enough air out of the system.

In order to bleed it correctly, you will need a scan tool to bleed the ABS module. Air gets trapped in there and a scan tool is the only thing you can use to get rid of the air.

Roy

STANDARD PROCEDURE - ANTILOCK BRAKE SYSTEM BLEEDING
The base brake's hydraulic system must be bled anytime air enters the hydraulic system. The ABS though, particularly the ICU (HCU), should only need to be bled when the HCU is replaced or removed from the vehicle. The ABS must always be bled anytime it is suspected that the HCU has ingested air. Under most circumstances that require the bleeding of the brakes hydraulic system, only the base brake hydraulic system needs to be bled.

When bleeding the ABS system, the following bleeding sequence must be followed to insure complete and adequate bleeding.
1. Make sure all hydraulic fluid lines are installed and properly torqued.
2. Connect the scan tool to the Data Link Connector. The connector is located under the lower steering column cover to the left of the steering column.
3. Using the scan tool, check to make sure the CAB (MK20e) or ABM (Mk25e) does not have any fault codes stored. If it does, clear them using the scan tool.

Warning: when bleeding the brake system wear safety glasses. A clear bleed tube must be attached to the bleeder screws and submerged in a clear container filled part way with clean brake fluid. Direct the flow of brake fluid away from yourself and the painted surfaces of the vehicle. Brake fluid at high pressure may come out of the bleeder screws when opened.

4. Bleed the base brake system using the standard pressure or manual bleeding procedure.
5. Using the scan tool, select ANTILOCK BRAKES, followed by MISCELLANEOUS, then BLEED BRAKES. Follow the instructions displayed. When the scan tool displays TEST COMPLETED, disconnect the scan tool and proceed.
6. Bleed the base brake system a second time. Check brake fluid level in the reservoir periodically to prevent emptying, causing air to enter the hydraulic system.
7. Fill the master cylinder reservoir to the full level.
8. Test drive the vehicle to be sure the brakes are operating correctly and that the brake pedal does not feel spongy.