Brake fluid pressure

Bad master cylinder . What are you using a scan tool for ? No need Unless your Installing a new Electro-Hydraulic Control Unit (EHCU) or new Brake Pressure Modulator Valve (BPMV).
Hydraulic Brake System Bleeding (Manual)
Caution: Refer to Brake Fluid Irritant Caution in the Preface section.
Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in the Preface section.
Place a clean shop cloth beneath the brake master cylinder to prevent brake fluid spills.
With the ignition OFF and the brakes cool, apply the brakes 3-5 times, or until the brake pedal effort increases significantly, in order to deplete the brake booster power reserve.
If you have performed a brake master cylinder bench bleeding on this vehicle, or if you disconnected the brake pipes from the master cylinder, you must perform the following steps:
3.1. Ensure that the brake master cylinder reservoir is full to the maximum-fill level. If necessary add GM approved brake fluid from a clean, sealed brake fluid container. Refer to Fluid and Lubricant Recommendations.
If removal of the reservoir cap and diaphragm is necessary, clean the outside of the reservoir on and around the cap prior to removal.
3.2. With the rear brake pipe installed securely to the master cylinder, loosen and separate the front brake pipe from the front port of the brake master cylinder.
3.3. Allow a small amount of brake fluid to gravity bleed from the open port of the master cylinder.
3.4. Reconnect the brake pipe to the master cylinder port and tighten securely.
3.5. Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal.
3.6. Loosen the same brake pipe to purge air from the open port of the master cylinder.
3.7. Tighten the brake pipe, then have the assistant slowly release the brake pedal.
3.8. Wait 15 seconds, then repeat steps 3.3-3.7 until all air is purged from the same port of the master cylinder.
3.9. With the front brake pipe installed securely to the master cylinder, after all air has been purged from the front port of the master cylinder, loosen and separate the rear brake pipe from the master cylinder, then repeat steps 3.3-3.8.
3.10. After completing the final master cylinder port bleeding procedure, ensure that both of the brake pipe-to-master cylinder fittings are properly tightened.
Fill the brake master cylinder reservoir with GM approved brake fluid from a clean, sealed brake fluid container. Ensure that the brake master cylinder reservoir remains at least half-full during this bleeding procedure. Add fluid as needed to maintain the proper level.
Clean the outside of the reservoir on and around the reservoir cap prior to removing the cap and diaphragm.
Install a proper box-end wrench onto the RIGHT REAR wheel hydraulic circuit bleeder valve.
Install a transparent hose over the end of the bleeder valve.
Submerge the open end of the transparent hose into a transparent container partially filled with GM approved brake fluid from a clean, sealed brake fluid container.
Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal.
Loosen the bleeder valve to purge air from the wheel hydraulic circuit.
Tighten the bleeder valve, then have the assistant slowly release the brake pedal.
Wait 15 seconds, then repeat steps 8-10 until all air is purged from the same wheel hydraulic circuit.
With the right rear wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the right rear hydraulic circuit install a proper box-end wrench onto the LEFT REAR wheel hydraulic circuit bleeder valve.
Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
With the left rear wheel hydraulic circuit bleeder valve tightened securely, after all air purged from the left rear hydraulic circuit, install a proper box-end wrench onto the RIGHT FRONT wheel hydraulic circuit bleeder valve.
Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
With the right front wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the right front hydraulic circuit, install a proper box-end wrench onto the LEFT FRONT wheel hydraulic circuit bleeder valve.
Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
After completing the final wheel hydraulic circuit bleeding procedure, ensure that each of the 4 wheel hydraulic circuit bleeder valves are properly tightened.
Fill the brake master cylinder reservoir to the maximum-fill level with GM approved brake fluid from a clean, sealed brake fluid container.
Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
If the brake pedal feels spongy, repeat the bleeding procedure again. If the brake pedal still feels spongy after repeating the bleeding procedure, perform the following steps:
21.1. Inspect the brake system for external leaks. Refer to Brake System External Leak Inspection.
21.2. Pressure bleed the hydraulic brake system in order to purge any air that may still be trapped in the system.
Turn the ignition key ON, with the engine OFF. Check to see if the brake system warning lamp remains illuminated.
Important: If the brake system warning lamp remains illuminated, DO NOT allow the vehicle to be driven until it is diagnosed and repaired.
If the brake system warning lamp remains illuminated, refer to Symptoms - Hydraulic Brakes

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.

1. Check the fluid level in the reservoir after bleeding each wheel. Add DOT3 fluid, if necessary.
2. If the master cylinder was disassembled or if the reservoir becomes empty, bleed the air from the master cylinder as follows:
   1. Disconnect the brake lines from the master cylinder.
   2. Slowly depress the brake pedal and hold it.
   3. Block off the outlet plug with your finger, and release the brake pedal.
   4. Repeat 3 or 4 times.
   
   
3. Bleed the brake starting with the one furthest from the reservoir and then the next furthest, etc.
   
4. Depress the brake pedal several times, then loosen the bleeder plug with the pedal held down.
5. At the point when fluid stops coming out, tighten the bleeder plug to 11 Nm (8 ft. lbs.), then release the brake pedal.
6. Repeat until all the air in the fluid has been bled out.
7. Repeat the procedure to bleed the air out of brake line for each wheel.
8. Check the fluid level and add DOT3 fluid if necessary.

on the brake calipers ther is a bleeder screw. It looks like a grease fitting.1) fill brake fluid 2) have a helper pump the brake pedal ( vehicle not running ) 6 - 8 times to the floor and release then press pedal to the floor and hold with foot pressure pressing down. 3) at this time loosen the bleeder valve and the pressure and air will release,( do not allow brake pedal to release or come up, continue to hold to the floor ! ) after pressure and any noticeable air bubbles and no more fluid comes out then this is the time to tighten or (close ) the bleeder screw. 4) continue this process untill no visable air bubbles are present, IT IS VERY IMPORTANT THAT YOU CHECK THE BRAKE FLUID RESERVOIR AFTER TWO BLEEDINGS AND FILL AS NECESSARY ! 5) Continue the procedure on the opposite side. Do the two front wheels and the rear wheels as a pair as the brake system is a two part system, FRONT & REAR

start from the fartherest place from brake master cylinder, that will be the rear passenger side wheel. it takes two people to bleed brakes. you will find the bleeder valve screws at the top of inside of the rear drums on both rear wheels, have someone pump the brakes up, will take at least 4 pumps of brake pedal, at 4th pump keep pressure on pedal while you break loose the bleeder valve on the rear wheel, fluid will come out and brake pedal will go down to floor, keep pressure on brake pedal until you've tightened the bleeder screw back [note] you'll only have to back the bleeder valve out about a half turn until you see the fluid come out. after you've done the rear brakes add brake fluid to the master cylinder as it will be low. then go to the front passeger side and you will find the bleeder screw on the brake caliper. repeat the same proceedure as back. remember that pressure on the pedal is a must until you've tightened those bleeder valve screws back or else it will **** air into the brake system. suggest that you bleed all 4 wheels not just the back. after you've bled the front make sure you add more brake fluid back to the master cylinder, it will be low again. hope this helps and thank you for choosing fixya.com

Bleeding brakes can be very frustrating.There are two ways you can do them 1 gravity feed;this means that you undo the bleeder screw on the caliper or the wheel cylinder and let the brake fluid flow until all air is removed from the system or 2 suction bleed; this involves going to your auto supply store and buying a small hand held pump that creates a suction which in turn,once connected over the bleeder screw,allows you to pull brake fluid and the air out of the system.If you have a friend to help you have them depress the brake pedal until it reaches the floor while you loosen the bleeder screw and discharge the air/fluid.Tighten the screw before the brake pedal is released,release the pedal and repeat.Keep checking the master cylinder and do not let the fluid run low.Don't pump the pedal repeatedly,brake fluid is hydroscopic,which means it can absorb air directly into itself.Slowly and firmly does it until you have purged all the air.You will know when it is all gone because hard pedal will come back.Good Luck

usually an indicator of either a loss of pressure due to low fluid and/or air in the system (brake fluid leak) or extremely worn rear brakes (if drum brakes in rear). possible causes include master cylinder (internal fluid pressure leak), external fluid leaks (calipers, lines, wheel cylinders), rear drum brakes extremely worn down or severely out of adjustment. normally worn disc brakes may reduce pedal height SOME, but seldom "to floor". but the "mushy" quote combined with the "floor" quote suggests a hydrolic fluid pressure problem.

BRAKE SYSTEM BLEEDING Diagonal Split System MASTER CYLINDER

1. Refill the master cylinder reservoir.
2. Push the plunger several times to force fluid into the piston.
3. Continue pumping the plunger until the fluid is free of the air bubbles.
4. Plug the outlet ports and install the master cylinder.

COMPLETE SYSTEM

1. Fill the master cylinder with fresh brake fluid. Check the level often during the procedure.
2. Starting with the right rear wheel, remove the protective cap from the bleeder, if equipped, and place where it will not be lost. Clean the bleed screw. When bleeding the brakes, keep face away from the brake area. Spewing fluid may cause facial and/or visual damage. Do not allow brake fluid to spill on the vehicle's finish; it will remove the paint.
3. If the system is empty, the most efficient way to get fluid down to the wheel is to loosen the bleeder about 1?2 - 3?4 turn, place a finger firmly over the bleeder and have a helper pump the brakes slowly until fluid comes out the bleeder. Once fluid is at the bleeder, close it before the pedal is released inside the vehicle. NOTE: If the pedal is pumped rapidly, the fluid will churn and create small air bubbles, which are difficult to remove from the system. These air bubbles will eventually congregate resulting in a spongy pedal.
   
4. Once fluid has been pumped to the caliper or wheel cylinder, open the bleed screw again, have the helper press the brake pedal to the floor, lock the bleeder and have the helper slowly release the pedal. Wait 15 seconds and repeat the procedure (including the 15 second wait) until no more air comes out of the bleeder upon application of the brake pedal. Remember to close the bleeder before the pedal is released inside the vehicle each time the bleeder is opened. If not, air will be induced into the system.
5. If a helper is not available, connect a small hose to the bleeder, place the end in a container of brake fluid and proceed to pump the pedal from inside the vehicle until no more air comes out the bleeder. The hose will prevent air from entering the system.
6. Repeat the procedure on remaining wheel cylinders in order:
   1. Step 1: Left front
   2. Step 2: Left rear
   3. Step 3: Right front
7. Hydraulic brake systems must be totally flushed if the fluid becomes contaminated with water, dirt or other corrosive chemicals. To flush, bleed the entire system until all fluid has been replaced with the correct type of new fluid.
8. Install the bleeder cap(s) on the bleeder to keep dirt out. Always road test the vehicle after brake work of any kind is done.

Teves® Anti-lock Brake System FRONT BRAKES

1. Turn the ignition switch OFF throughout this procedure.
2. Using at least 50 lbs. pressure on the brake pedal, depress the pedal at least 25 times; a noticeable change in pedal pressure will be noticed when the accumulator is discharged.
3. Remove the reservoir cap. Check and/or refill the master cylinder reservoir.
4. Using the bleeder adapter tool, install it onto the fluid reservoir.
5. Attach a diaphragm type pressure bleeder to the adapter and charge the bleeder to 20 psi.
6. Using a transparent vinyl tube, connect it to either front wheel caliper and insert the other end in a beaker 1?2 full of clean brake fluid.
7. Open the bleeder valve 1?2 - 3?4 turn and purge the caliper until bubble free fluid flows from the hose.
8. Tighten the bleeder screw and remove the bleeder equipment.
9. Turn the ignition switch ON and allow the pump to charge the accumulator.
10. After bleeding, inspect the pedal for sponginess and the brake warning light for unbalanced pressure; if either of the conditions exist, repeat the bleeding procedure.

REAR BRAKES

1. Turn the ignition switch OFF.
2. Using at least 50 lbs. pressure on the brake pedal, depress the pedal at least 25 times; a noticeable change in pedal pressure will be noticed when the accumulator is discharged.
3. Check and/or refill the master cylinder reservoir.
4. Turn the ignition switch ON and allow the system to charge. NOTE: The pump will turn OFF when the system is charged.
   
5. Using a transparent vinyl tube, connect it to a rear wheel bleeder valve and insert the other end in a beaker 1?2 full of clean brake fluid.
6. Open the bleeder valve 1?2 - 3?4 turn and slightly depress the brake pedal for at least 10 seconds or until air is removed from the brake system. Close the bleeder valve. NOTE: It is a good idea to check the fluid level several times during the bleeding operation. Remember, depressurize the system before checking the reservoir fluid.
   
7. Repeat the bleeding procedure for the other rear wheel.
8. After bleeding, inspect the pedal for sponginess and the brake warning light for unbalanced pressure; if either of the conditions exist, repeat the bleeding procedure.

Bosch® III Anti-lock Brake System

1. Turn the ignition switch OFF.
2. Using at least 50 lbs. pressure on the brake pedal, depress the pedal at least 25 times; a noticeable change in pedal pressure will be noticed when the accumulator is discharged.
3. Check and/or refill the reservoir to the full mark.
4. Using a transparent vinyl hose, connect it to a pump bleeder screw and insert the other end in a beaker 1?2 full of clean brake fluid.
5. Loosen the bleeder screw 1?2 - 3?4 turn. Turn the ignition switch ON; the pump should run forcing fluid from the hose. When the fluid becomes bubble-free, turn the ignition switch OFF, tighten the bleeder screw.
6. Move the transparent vinyl hose to the hydraulic unit bleeder screw. Loosen the bleeder screw 1?2 - 3?4 turn. Turn the ignition switch ON; the pump should run forcing fluid from the hose. When the fluid becomes bubble-free, turn the ignition switch OFF, tighten the bleeder screw.
7. Disconnect the bleeder hose.
8. Turn the ignition switch ON and allow the hydraulic unit to charge; the pump should turn OFF after 30 seconds.

Bosch® 2U Anti-lock Brake System

1. Turn the ignition switch OFF.
2. Using at least 50 lbs. pressure on the brake pedal, depress the pedal at least 25 times; a noticeable change in pedal pressure will be noticed when the accumulator is discharged.
3. Check and/or refill the reservoir to the full mark.
4. Using a transparent vinyl hose, connect it to a pump bleeder screw and insert the other end in a beaker 1?2 full of clean brake fluid.
5. Loosen the bleeder screw 1?2 - 3?4 turn. Turn the ignition switch ON; the pump should run forcing fluid from the hose. When the fluid becomes bubble-free, turn the ignition switch OFF, tighten the bleeder screw.
6. Move the transparent vinyl hose to the hydraulic unit bleeder screw. Loosen the bleeder screw 1?2 - 3?4 turn. Turn the ignition switch ON; the pump should run forcing fluid from the hose. When the fluid becomes bubble-free, turn the ignition switch OFF, tighten the bleeder screw.
7. Disconnect the bleeder hose.
8. Turn the ignition switch ON and allow the hydraulic unit to charge; the pump should turn OFF after 30 seconds.

Here is the procedure from the service manual. I would add just one thing. Do each wheel in this order

1. right rear wheel
2. left rear wheel
3. right front wheel
4. left front wheel

BLEEDING

HINT: If any work is done on the brake system or if air in the brake lines is suspected, bleed the air from the system.

NOTICE: Do not let brake fluid remain on a painted surface. Wash it off immediately.


a)FILL BRAKE RESERVOIR WITH BRAKE FLUID Fluid:SAE J1703 or FMVSS No. 116 DOT3

b)BLEED MASTER CYLINDER HINT: If the master cylinder has been disassembled or if the reservoir becomes empty, bleed the air from the master cylinder.

c)Disconnect the brake lines from the master cylinder. SST 09023-00100 Slowly depress the brake pedal and hold it.

Block off the outlet plug with your finger and release the brake pedal.
Repeat (b) and (c) 3 or 4 times.


BLEED BRAKE LINE

1. Connect the vinyl tube to the caliper or wheel cylinder bleeder plug.
2. Depress the brake pedal several times, then loosen the bleeder plug with the pedal held down.
3. At the point when fluid stops coming out, tighten the bleeder plug, then release the brake pedal. Torque: (Bleeder plug) Front brake caliper
: 8.3 Nm (85 kgf-cm, 74 inch lbs.) Rear wheel cylinder: 8.5 Nm (87 kgf-cm, 75 inch lbs.)
4. Repeat (b) and (c) until all the air in the fluid has been bled out.
5. Repeat the above procedure to bleed the air out of the brake line for each wheel.

CHECK FLUID LEVEL IN RESERVOIR Check the fluid level and add fluid if necessary. Fluid: SAE J1703 or FMVSS No. 116 DOT3

1. Place a clean shop cloth beneath the brake master cylinder to prevent brake fluid spills.
2. With the ignition OFF and the brakes cool, apply the brakes 3-5 times, or until the brake pedal effort increases significantly, in order to deplete the brake booster power reserve.

Fill the brake master cylinder reservoir with DOT-3 brake fluid from a clean, sealed brake fluid container. Ensure that the brake master cylinder reservoir remains at least half-full during this bleeding procedure. Add fluid as needed to maintain the proper level. Clean the outside of the reservoir on and around the reservoir cap prior to removing the cap and diaphragm.

1. Install a proper box-end wrench onto the RIGHT REAR wheel hydraulic circuit bleeder valve.
2. Install a transparent hose over the end of the bleeder valve.
3. Submerge the open end of the transparent hose into a transparent container partially filled DOT-3 brake fluid from a clean, sealed brake fluid container.
4. Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal.
5. Loosen the bleeder valve to purge air from the wheel hydraulic circuit.
6. Tighten the bleeder valve, then have the assistant slowly release the brake pedal.
7. Wait 15 seconds, then repeat these steps until all air is purged from the same wheel hydraulic circuit.
8. Repeat this procedure with the LEFT FRONT, then LEFT REAR and finally the RIGHT FRONT.
9. Fill the brake master cylinder reservoir to the maximum-fill level with DOT-3 brake fluid from a clean, sealed brake fluid container.
10. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.