We’ve been having a lot of issues with the brakes on a 2000 Dodge Caravan. Within the last year it has been taken into several mechanics for the brakes not working properly. A new master cylinder and a new brake caliper have been put in along with multiple bleeding of the brakes. When I looked at the car I very quickly found that there was air in the lines as the peddle went to the floor. I put it on jack stands and had another person press the brakes as I checked to see if I could spin the tires. Two of the tires, the front driver and rear passenger would spin with the brake pressed. When the brake was pumped several times the brakes would apply for both tires and I couldn’t spin them.
I bled the front brake and now the all four tires stopped (brake would apply) with one press. All seemed good and the brakes seemed to work 100%. A week later and the brakes are back to having air in the lines like the way it was when I started. The brake fluid was actually higher then when I left it which was interesting. There is no signs of any leak or brake fluid on the ground (which why should there be the brake fluid was higher than I left it).
My best guess is, air is getting in the line somehow but fluid is not leaking out. What would cause this? Has anyone experienced this? The system does have ABS, not sure if this would play a role.
Please help, I’ve worked on brakes for mall my life but never experienced anything like this.