Rear brake system needs to be constantly bled; no fluid loss

anual Bleeding
The primary and secondary (front and rear) hydraulic brake systems are individual systems and are bled separately. Bleed the longest line first on the individual system being serviced. During the complete bleeding operation, DO NOT allow the brake master cylinder reservoir (2K478) to run dry. Keep the master cylinder reservoirs filled with High Performance DOT-3 Brake Fluid C6AZ-19542-AA or DOT-3 equivalent meeting Ford specification ESA-M6C25-A. Never reuse brake fluid that has been drained from the hydraulic system or has been allowed to stand in an open container for an extended period of time.
NOTE: Non-ABS vehicles have the brake master cylinder (2140) mounted at an angle to the horizontal, bleeding may be better performed if the vehicle is positioned so that the brake master cylinder is horizontal.

1. To bleed the brake system, position a suitable box wrench on the bleeder fitting on the brake wheel cylinder. Attach a rubber drain tube to the bleeder fitting. The end of the tube should fit snugly around the bleeder fitting.

1. Submerge the free end of the tube in a container partially filled with clean brake fluid, and loosen the bleeder fitting approximately three-quarters of a turn.

1. Have an assistant push the brake pedal (2455) down slowly through its full travel. Close the bleeder fitting, then return the brake pedal to full-release position. Repeat this operation until air bubbles cease to appear at the submerged end of the bleeder tube.

1. When the fluid is completely free of air bubbles, secure the bleeder fitting and remove the bleeder tube.

1. Repeat this procedure at the brake wheel cylinder on the opposite side. Refill the brake master cylinder reservoir after each wheel cylinder is bled, and install the master cylinder cap and gasket. Ensure the diaphragm-type gasket is properly positioned in the master cylinder cap. When the bleeding operation is completed, the fluid level should be at the MAX line to 4.0 mm (0.16 inch) below.

1. If the primary (front brake) system is to be bled, repeat Steps 2 through 5 at the right front brake caliper and ending at the left front brake caliper. Bleed the brake master cylinder at the bleed screw after all calipers are bled.

1. After disc brake service, ensure that the disc brake pistons are returned to their normal positions and the shoe and lining assemblies are properly seated. This is accomplished by depressing the brake pedal several times until normal pedal travel is established.

1. Check pedal feel. If brake pedal feels "spongy" repeat bleed procedure, or use the Vacuum method as outlined in Section 06-09, but bleed both rear calipers first.

You can also pressure bleed it. If the abs module needs to be bleed, that requires a special tool. If you have already tried the procedure posted and it didn't work, I'm not sure what next?

If the master cylinder is replaced, care must be taken to prime the new master cylinder by removing all of the air and completely filling it with brake fluid. The spongy feeling is air that is still in the circuits. You will need to bleed the back brakes as well as the front ones again. The order that you bled them seems correct, but perhaps there remained some air in the main trunk lines.

For the best results 2 people are needed. Start at the further distance wheel cylinder and bleed at least three (3) master cylinder reservoir volumes of fluid (back brakes). Bleed the fluid with use of a piece of tubing attached to the bleed port that is long enough to reach almost to the bottom of a long neck or tall clear jar (clear drink bottle works well). When the bleeding begins, after one or two brake pedal pushes, make sure that the end of the tubing is below the surface of the fluid and keep it under. It best to have a clear bleed line (to observe air). Keep pumping the brake pedal while being careful to not completely empty the master cylinder reservoir (leave 1/4 full always). Repeat the same technique for each wheel cylinder with at least two (2) reservoirs full for front brakes. Partially close the bleed ports when almost finished (at least 5 pedal strokes without exit of any air). Completely close the ports during the down stroke of the brake pedal, with the tubing still attached. Be sure each bleed port is closed snuggly.
Most of the brake fluid can be reused, but not the darker portion at the bottom of the jar.

PRESSURE BLEEDING

MANUAL BLEEDING

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For vehicles equipped with an Anti-lock Brake System (ABS), please refer to the ABS bleeding procedure at the end of this section.
The purpose of bleeding the brakes is to expel air trapped in the hydraulic system. The system must be bled whenever the pedal feels spongy, indicating that compressible air has entered the system. It must also be bled whenever the system has been opened or repaired. If you are not using a pressure bleeder, you will need a helper for this job.

WARNING Never reuse brake fluid which has been bled from the brake system.

MASTER CYLINDER

See Figure 1
If the master cylinder is off the vehicle, it can be bench bled.

1. Secure the master cylinder in a bench vise.
2. Connect 2 short pieces of brake line to the outlet fittings, bend them until the free end is below the fluid level in the master cylinder reservoirs.
3. Fill the reservoir with fresh DOT 3 type brake fluid.
4. Using a wooden dowel, or equivalent, pump the piston slowly several times until no more air bubbles appear in the reservoirs.

Fig. Fig. 1: Attach bleeding tubes to the master cylinder and position them as shown

1. Disconnect the 2 short lines, refill the master cylinder and securely install the cylinder cap.
2. If the master cylinder is on the vehicle, it can still be bled, using a flare nut wrench.
3. Open the brake lines slightly with the flare nut wrench, while pressure is applied to the brake pedal by a helper inside the vehicle.
4. Be sure to tighten the line before the brake pedal is released.
5. Repeat the process with both lines until no air bubbles come out.
6. Bleed the complete brake system, if necessary.

If the master cylinder has been thoroughly bled and filled to the proper level upon installation into the vehicle, it is not necessary to bleed the entire hydraulic system.

PRESSURE BLEEDING

When bleeding the brakes, air may be trapped in the brake lines or valves far upstream, as much as 10 feet from the bleeder screw. Therefore, it is very important to have a fast flow of a large volume of brake fluid when bleeding the brakes, to make sure all of the air is expelled from the system.
On Cirrus, Stratus, Sebring convertible and Breeze models, the following wheel sequence should be used to ensure that all the air is removed from the system:


Left rear wheel Right front wheel Right rear wheel Left front wheel
On Sebring coupe and Avenger models, the following wheel sequence should be used to ensure that all the air is removed from the system:


Right rear wheel Left front wheel Left rear wheel Right front wheel

1. You should use bleeder tank tool C-3496-B or equivalent, with the required adapter for the master cylinder reservoir to pressurize the hydraulic system for bleeding. Make sure to follow the manufacturer's directions for using a pressure bleeder.
2. Attach a clear plastic hose to the bleeder screw located at the right rear wheel, then place the hose into a clean jar that has enough fresh brake fluid to submerge the end of the hose.
3. Open the bleeder screw at least one full turn or more to get a steady stream of fluid.
4. After about 4-8 oz. of fluid has been bled through the brake system and an air-free flow is maintained in the hose and jar, close the bleeder screw.
5. Repeat the procedure at all the other remaining bleeder screws. Then, check the pedal for travel. If pedal travel is excessive or has not improved, enough fluid has not passed through the system to expel all of the trapped air. Be sure to monitor the fluid level in the pressure bleeder. It must stay at the proper level so air will not be allowed to re-enter the brake system through the master cylinder reservoir.
6. Once the bleeding procedure is complete, remove the pressure bleeding equipment from the master cylinder.

MANUAL BLEEDING

See Figure 2
Proper manual bleeding of the hydraulic brake system will require the use of an assistant.
On Cirrus, Stratus, Sebring convertible and Breeze models, the following wheel sequence should be used to ensure that all the air is removed from the system:


Left rear wheel Right front wheel Right rear wheel Left front wheel
On Sebring coupe and Avenger models, the following wheel sequence should be used to ensure that all the air is removed from the system:


Right rear wheel Left front wheel Left rear wheel Right front wheel

Fig. Fig. 2: With a clear plastic hose in a container of clean brake fluid, open the bleeder screw at least one full turn

1. Attach a clear plastic hose to the bleeder screw located at the right rear wheel, then place the hose into a clean jar that has enough fresh brake fluid to submerge the end of the hose.
2. Have an assistant pump the brake pedal 3-4 times, and hold it down before the bleeder screw is opened.
3. Open the bleeder screw at least one full turn. When the bleeder screw opens, the brake pedal will drop.
4. Close the bleeder screw. Release the brake pedal only AFTER the bleeder screw is closed.
5. Repeat the procedure 4 or 5 times at each bleeder screw, then check the pedal for travel. If the pedal travel is not excessive, or has not been improved, enough fluid has not passed through the system to expel all of the trapped air. Make sure to watch the fluid level in the master cylinder reservoir. It must stay at the proper level so air will not re-enter the brake system.
6. Test drive the vehicle to be sure the brakes are operating correctly and that the pedal is solid.

In this case, you will need to leak the for wheels, never leak only one or two wheels when adjusting the breaks. If the leaking continues you need to check the conduit for potential damages. If pedal stay soft after checking everything else, check the break fluid unit. The unit has a piston if I'm not wrong. The piston has some parts that are of rubber material which can wear out or get damaged.

Hi, bleeding your rear brakes with engine running, you should get enough pressure out of the lines to squirt 3-4 feet. In other words, good pressure. If all you get is a trickle, you probably have a bad master cylinder. Just because its full of fluid, does not mean the seals arent shot. If you have bled them in order, left rear,right rear,left front,right fornt and have bled them enough to get fresh fluid out of each one without achieving good solid pressure at all wheels, replace your master cylinder. There is a proportioning valve, but usually it will affect only one wheel when going out, usually the left rear.
Brake pedal height comes from the rear brakes, so if you have bad pressure there, you will never get a good pedal. Eventually with a bad master, your brakes will go completly out..Mike

You may need to further bleed the brakes. Something pumping to bleed the brakes can **** in air at the brake fluid reservoir. Try using a vacuum pump to **** out brake fluid from the release screw at the brake side. Make sure you always have enough fluid at the reservoir.

Bench Bleed the M/C first, then do not let it run dry during system bleeding. Parts stores sell a kit that helps installed m/c bleeding.

Bleeding the Brakes
EXCEPT HYDRO-BOOST OR ABS(see Figures 1, 2, 3 and 4)
To bleed the brakes on a vehicle equipped with ABS, please refer to the ABS bleeding procedure in this section.
The brake system must be bled when any brake line is disconnected or there is air in the system.
Never bleed a wheel cylinder when a drum is removed.

1. Clean the master cylinder of excess dirt and remove the cylinder cover and the diaphragm.
2. Fill the master cylinder to the proper level. Check the fluid level periodically during the bleeding process and replenish it as necessary. Do not allow the master cylinder to run dry, or you will have to start over.
3. Before opening any of the bleeder screws, you may want to give each one a shot of penetrating solvent. This reduces the possibility of breakage when they are unscrewed.

Fig. 1: Connect one end of a clear plastic tube to the bleeder screw and submerge the other end in clean brake fluid



Fig. 2: Have an assistant pump, then hold in the brake pedal, while you bleed each wheel



Fig. 3: Using the combination valve depressor-R/V Series



Fig. 4: Using the combination valve depressor-C/K Series

1. Attach a length of vinyl hose to the bleeder screw of the brake to be bled. Insert the other end of the hose into a clear jar half full of clean brake fluid, so that the end of the hose is beneath the level of fluid. The correct sequence for bleeding is to work from the brake farthest from the master cylinder to the one closest; right rear, left rear, right front, left front.
2. The combination valve must be held open during the bleeding process. A clip, tape, or other similar tool (or an assistant) will hold the metering pin in.
3. Depress and release the brake pedal three or four times to exhaust any residual vacuum.
4. Have an assistant push down on the brake pedal and hold it down. Open the bleeder valve slightly. As the pedal reaches the end of its travel, close the bleeder screw and release the brake pedal. Repeat this process until no air bubbles are visible in the expelled fluid.

Make sure your assistant presses the brake pedal to the floor slowly. Pressing too fast will cause air bubbles to form in the fluid.

1. Repeat this procedure at each of the brakes. Remember to check the master cylinder level occasionally. Use only fresh fluid to refill the master cylinder, not the stuff bled from the system.
2. When the bleeding process is complete, refill the master cylinder, install its cover and diaphragm, and discard the fluid bled from the brake system.

HYDRO-BOOSTThe system should be bled whenever the booster is removed and installed.

1. Fill the power steering pump until the fluid level is at the base of the pump reservoir neck. Disconnect the battery lead from the distributor.
   

Remove the electrical lead to the fuel solenoid terminal on the injection pump before cranking the engine.

1. Jack up the front of the car, turn the wheels all the way to the left, and crank the engine for a few seconds.
2. Check steering pump fluid level. If necessary, add fluid to the "ADD" mark on the dipstick.
3. Lower the car, connect the battery lead, and start the engine. Check fluid level and add fluid to the "ADD" mark, as necessary. With the engine running, turn the wheels from side to side to bleed air from the system. Make sure that the fluid level stays above the internal pump casting.
4. The Hydro-Boost system should now be fully bled. If the fluid is foaming after bleeding, stop the engine, let the system set for one hour, then repeat the second part of Step 4.
   

The preceding procedures should be effective in removing the excess air from the system, however sometimes air may still remain trapped. When this happens the booster may make a gulping noise when the brake is applied. Lightly pumping the brake pedal with the engine running should cause this noise to disappear. After the noise stops, check the pump fluid level and add as necessary.


Hope helps with this (remember comment and rated this).

You'll need to start bleeding the brake system at the Master cylinder to determine where the problem lies.

The lines coming out of the master cylinder will need to be loosened & bled there, initially you can just do the back ones to identify the problem, but once fixed, the system will have to be bled from the Master cylinder first, then the farthest wheel from it, then next farthest, then next, until you do the drivers wheel last.

This method of bleeding the brakes prevents air from crossing from one line to another, causing air to be left in the system.

Back to bleeding the rear brakes first: As someone pumps up the brake pressure, making sure the resivoir stays full, with the cap on between bleeding, and have the person pressing the pedal to do these thngs.
1. Always move the pedal slowly, pressing and releasing.
2. Never release the pressure on the pedal after bleeding a brake, until the line is tightened, then release slowly to prevent air from getting into the fluid.

You should of course get fluid at the master cylinder when you bleed it (or just replace it), then you'll need to bleed the line at the right rear wheel (first) a few times to get fluid if it's been leaking, then the left rear wheel. If you get pressure but no fluid to the rear and the master cyliinder did have pressure released when you bled it, there is either a restriction in the line itself, or the porportioning valve could be damaged. (unusual for the valve to go bad actually, inspect lines for damage such as being pinched if you're getting pressure but no fluid.

Final test if it hasn't been resolved-remove lines at porportioning valve & make sure fluid is leaving/entering there as it should. If you find it defective, a good replacement can come from a salvage yard, or you can buy them new.

Brake fluid on the floorboard under the dash near the brake pedal=bad Master Cylinder.

good luck

you still air in system or a bad master cylinder or brake booster.