Your brake booster is malfunctioning
How to change the brake switch on a 2004 Jeep grand Cherokee Laredo
brake hose's are about $20 each , steel lines can be replaced in sections for about $5 a section
If equipped, it is above the liftgate glass.
Either is OK
A 2005 Jeep Grand Cherokee uses DOT 3 fluid.
it is hissing because there is a vacume leak in the brake booster it will require a new brake booster
Hissing from the brake pedals being push indicates that there is air in the brake system. It also indicates that the brake pads may be wore down and are not able to grab to stop the car.
air coming out of the brake lines... that is if its a truck. if you aply the parking brake.
Faulty Vacuum Brake Booster.
By the hissing noise it sounds like you need a new brake booster
The power brake booster may be going bad.
How to change the brake switch on a 2004 Jeep grand Cherokee Laredo
The emergency or parking brake on 2003 Jeep Grand Cherokee operates a set of brake shoes inside a hub on the rear axles, this is incorporated into the disc brake setup.
bad master cylinder
The brake light switch is behind the brake pedal.
I have the same problem, hissing until touching the brake. I just read on another site that is the brake booster leaking, and since it's a vacuum leak it could trigger engine light to go on. I need to look further to discover whether it's a necessary repairsusan
Sounds like the power brake booster is bad. Get it checked out.