How to find a leak in the brake system - 1999 Jeep Cherokee

Try bleeding out the fluid. How to Bleed Your Brakes dummies

Check the fluid in the master cylinder. If there is a leak in the brake system, one side of the master cylinder will lose its fluid. The is a proportioning valve that is part of the brake system that will shift under uneven pressure to shut off the leaking side. When this occurs it will light the brake lamp. If your master cylinder reservoir is low on one side, have the brake system checked for leaks immediately and repaired.

Might be a leak somewhere in brake lines. Or some gasket gone bad in brakes (then there is probably a leak as well). If no leak then I assume there is some air in the brake system, sounds like in lines which lead to back brakes so I suggest you bleed back brakes (preferably bleed the whole brake system). In my car (not bolero though) there is some kind of braking power balancing system with extra bleeding screw at the back and this could have air in too. You can find further information how to bleed braking system from your car manual or generally from the Internet. Usual drill is to bleed the furthest brake first then continue until closest brake to your car brake fluid reservoir.
PS: If your brake pedal feels soft and get harder by each push then there is definitely air in the system. If it stays soft you might have a leak.

Check the fluid level. Low brake fluid level can cause the brake light to come on warning you of low fluid. It will be off when the car is level, but as you hit bumps and hit your brakes, the fluid that is in there will slosh around indicatind low fluid. Don't overfill and only use DoT 3 brake fluid. Do not substitute anything else.

Hi, the likely cause is a leak that has used all the fluid in the reservoir and drawn air into the system. You will need to find the leak, repair it, and then bleed the whole system of air. Likely places for the leak are at the back of the master cylinder or at any of the 4 wheels. It is possible to draw air without a leak if your front brakes are extremely worn. If this is the case, replace the front brake pads and bleed only the front wheels. Please let me know if you have questions or need instructions, and thanks for using FixYa.

possible leak in brake system. if not then you have a bad master cylinder. have to replace it.

System has a fault and needs troubleshooting.

power booster or master cylinder .

First, re-fill the master, pump the brake and check everything for leaks. Smaller side serves the rear brakes. If you find no leaks, replace the master cylinder and bleed the system and again check for leaks. You have a split system. When one half goes out, the other half does not. That is why you still have partial braking (better than old single systems on 1950's cars that once compromised, you had nothing to stop with.)

If the brake warning light comes on when you apply the brakes, or is on continuously, it means that hydraulic pressure has been lost in one side of the brake system or that the fluid level in the master cylinder is dangerously low (due to a leak somewhere in the brake system). In either case, the fluid level in the master cylinder should be checked. Adding brake fluid to the master cylinder reservoir may temporarily solve the problem. But if there's a leak, the new fluid will soon be lost and the warning light will come back on.
Brake fluid leaks are serious because they may cause the brakes to fail! So avoid driving the vehicle until the system can be inspected to determine what's wrong. Leaks can occur in brake hoses, brake lines, disc brake calipers, drum brake wheel cylinders or the master cylinder itself. Wet spots at hose or line connections would indicate a leak that needs to be fixed.
Leaking brake fluid can also contaminate the brake linings, causing them to slip or grab. The uneven braking action that results may cause the vehicle to veer to one side when the brakes are applied. Brake shoes or pads that have been contaminated with brake fluid cannot be dried out and must be replaced.