How can I reset the brake warning light on my 95 Ram 2500. The caiper were off and the fluid was low causing the pressure switch to turn on the warning light. Fluid is good now, no leaks. Thanks.

Some Chrysler ,Jeep and Dodge vehicles have ttye pressure sensors calibrated to the vevicle,so therefore if you change the
tyres to a different type you will need to take your vehicle to a C.J.D.
service department to have the computer of your car re-programmed to accept the new tyres

Usually the warning light involves the low fluid switch on the master cylinder, the switch on the equalizer valve if equipped, and the switch on the parking brake. One of those switches may not be working.

Please also note that the low fluid level sensor in your brake master cylinder will also make this light come on. If the brake fluid is low in the master cylinder, you need to find out WHY! There is either an hydraulic leak in the system or the disc brake pads are worn VERY thin. Then again, the low fluid level sensor could be faulty.

There is also a difference in brake systems available in your vehicle. If you do not have a fluid level switch in you master cylinder, there will be a pressure differential switch mounted between the fluid lines just below the antilock brake module. If this switch is causing the brake light to come on, it is usually because of a fluid leak somewhere in the system. If the hydraulic pressure on one dide of the switch or the other drops for some reason, it will cause the piston in the switch to shift to the side and turn the switch on. Again, you vehicle may be equipped with one or the other - you simply have to look.

To find out if it is the low fluid level switch, the pressure differential switch` or the parking brake switch, just unplug each of the switches to see if the light goes out.

If it actually is the parking brake switch, it is usually because the parking brake lever assembly is malfunctioning or you may have a stuck forward cable that is not allowing the pedal to return to the full UP position. Parking brake lever/pedal assembly failures are pretty common. I have changed quite a few of them.

replace the brake pressure switch, this switch is located on the master i think, code 78 is brake foundation, the computer sees brake pressure switch feedback voltage low, this can be caused by a leak , so the pedal would sit low or sink or a bad connection to switch or switch itself, also make sure brake fluid is full. good day

Hi, there are 3 things that can cause the light to stay on.
One is the parking brake switch, which may have shorted internally or to chassis ground. The switch is above the parking brake pedal. If the connector is still on the switch remove it. If the light goes out, replace the switch.

The second is the fluid level in the master cylinder reservoir. Check fluid level. If good, check the sensor by taking the cable off. If that puts the light out, replace the sensor.

The third is the pressure differential warning switch. The switch turns on when there is a brake failure. You would probably know if this happened. If not, check all wheels for brake fluid leaks. If you have a leak and need help with repair procedures, please get back to me. If you have completed repairs, please read the procedures below from autozone.com to reset the warning switch.

Please let me know if you have any questions and thanks for using FixYa.


From autozone.com:
A pressure differential warning valve is incorporated in the hydraulic system. The signal from this valve consists of a warning light on the dashboard activated by a differential pressure switch located below the master cylinder. The signal indicates a hydraulic pressure differential between the front and rear brakes of 80-150 psi, and should warn the driver that a hydraulic failure has occurred.
After repairing and bleeding any part of the hydraulic system the warning light may remain on due to the pressure differential valve remaining in the off-center position. To centralize the valve a pressure difference must be created in the opposite branch of the hydraulic system that was repaired or bled last.
Front wheel balancing of cars equipped with disc brakes may also cause a pressure differential in the front branch of the system.

VALVE CENTERING PROCEDURE

1. Turn the ignition to either the ACC or ON position.
2. Check the fluid level in the master cylinder reservoirs. Fill to within 1 / 4 in. (6mm) of the top if necessary.
3. Depress the brake pedal firmly. The valve will centralize itself causing the brake warning light to go out.
4. Turn the ignition off.
5. Prior to driving the vehicle, check the operation of the brakes and obtain a firm pedal.

If the valve lifters are quiet you most likely have oil pressure even with gauge showing "0".Sounds like the oil pressure switch going bad.I would try that first.

The brake fliud resorvoir may have a sensor on it that is at fault. Also if the brake pads are getting very tin the light will stay on for the brake fluid is low if not filled. Fill the fluid up and see if the light goes off. The sensor if equipt will have two wires for a conection

you need to find out why they are spongy? fluid low? brake fluid leak? master cylinder problem? ck the fluid level, if its real low, you need to find out where it went.

You Must determine that Master Cylinder is NOT LEAKING into the Brake BOOSTER this is a Leak that CANNOT be Detected Easyly, If not Rear Brake SHOES Worn OUT Can CAUSE LOW Brake Pedal Problem

Are you refering to the brake light on the dash? If so check the brake fluid level in the master cylinder. If the fluid is low it will cause the brake light to stay on.