A leak of fluid somewhere. Check all lines and hoses for a leak and fix until the pedal is firm and does not loose pressure
Usually, a loss of pressure in your brake system means that there is a hole somewhere in the system. A leaking brake line or a punctured reservoir could cause a loss of pressure. A bad master cylinder could also cause a loss of pressure in the back brakes.
A cause for high oil pressure could be related to the type of oil that is being used in the vehicle. Thicker based oils such as 10w40 and higher could cause high oil pressure.
Start by checking the fuel pressure.
leaking wheel cylinder
Your car could be losing brake pressure because you have a bad ABS control module. It also could be a bad brake booster.
there could be a brake light switch located around the brake pedal, this commonly wears out on a Chevy truck The brake sockets are no good There was a campaign for updated brake sockets. Has it been done by a Saturn dealer? If not get it done and you should be fine
Yes, a bad master cylinder can cause one brake to lock up. If the master cylinder is malfunctioning, it may lead to uneven pressure distribution in the brake system, causing one brake caliper to receive too much pressure. This can result in that brake clamping down and not releasing properly, leading to a lock-up. Regular maintenance and inspection are crucial to prevent such issues.
Air in the brake lines
That is normal as there is a parking "gear" and that has to hold the vehicle in place when on a hill. There is a lot of pressure on that gear - you are releasing the pressure therefore the large "cluck" when on a hill. Best way to not cause this is put the emergency brake on when parking - release the brake to set the e-brake and then place the van in park to not put the pressure on the transmission.
There are a lot of different things that could be wrong. But initially what it means is that your brakes are going out or are out You should start by checking your brake fluid if that is low it would cause you to loose pressure. If your brake fluid is low and you fill it things should get better if you don't have a hole in your brake line. If the fluid is full check your brake pads
Could be a wheel bearing, brake pads worn,
A brake fluid leak in the brake system, LOW BRAKE FLUID.