On the driver side of the firewall. there is a reservoir. Depending on the year it could have one yellow cap or two black caps.
check your brake fluid it is probably low
Common causes are low brake fluid levels in the master cylinder reservoir, or air bubbles or leaks have been detected in the brake lines.
Brake fluid is added to the brake master cylinder reservoir, under the hood on the driver side.
In the master cylinder.
Fuse or brake light switch are most likely.
Go to your local library and find the manual
You have to go to the dealer. The dipstick is a special tool only available to them.
Empty it holds almost 9 quarts.
Master cylinder. Located on the firewall, driver's side, in front of the brake booster.
Go to a Dodge dealer and buy a new neck, will come with a new seal.
The reservoir is located on the driver's side rear of the engine compartment below the wiper boat assembly. Be sure to clean the cap before removing it and use the correct type of brake fluid as indicated on the cap. Normally, as the brake linings wear the fluid level in the reservoir drops. The level should not go so low as to affect functioning of the brakes or turn on a warning indicator lamp. When the linings are replaced, unless fluid is removed from the system, the fluid will rise to its previous level. If additional fluid had been added to the reservoir, it may overflow and spill brake fluid out. If not immediately cleaned off, brake fluid can damage paint, metal, plastic, and wiring. Keep in mind that if you have a low brake fluid level you should check for worn brake linings or fluid leaks. Excessively worn linings or leaking brake fluid can lead to brake failure if not corrected.
2004 dodge grand caravan 4.0sxt cuts up when apply brake in gear and rpm go up and down.