I deliver mail in a rural area in a 1993 Ford Taurus. I have taken my car to my mechanic numerous times lately and we cannot figure out what is up with my brakes. Since the weather started turning cooler, my brakes “on some days” are hard when I get in it. After mashing them (hard) from mailbox to mailbox for about 5 minutes, it goes back to normal. It does not happen everyday, but it seems to be more often if it is real cold outside.
We have already changed out the brake booster, master cylinder, rear brakes and drums, and front brakes and rotors.
We can’t figure this out and the mechanic even consulted a guy over the Ford dealership garage. Aside from this occasional fluke, the car runs fine. Any suggestions?
Has the mechanic been able to experience the car when the brakes are acting up? When they ar acting up, it would be easier to determine the cause of the hard brakes, like bad booster or even binding linkage. If they are always behaving when the mechanic looks at them, then it is just a guessing game.
How cool? If the vacuum hose to the booster has moisture in it freezing temperatures will plug the check valve with ice.
On the tail end of Rod Knox’s thought I wonder if the vacuum hose to the booster and the check valve were changed when the booster was. Moisture in the vac line would be one thing, but maybe it is obstructed. If the check valve is stuck that would also result in the same thing. Basically it sounds like its taking a long time for the booster to take a vacuum.
There is a simple way to check if your booster is working. Withe the engine off, pump the pedal until it hardens. Then, while pushing on the pedal, start the engine. If the booster is working properly the pedal should drop a bit and become softer in feel.
Along with the other brake work, did your mechanic completely flush out the old fluid and put new fluid into the hydraulic system?