I have a 1989 Ford Tempo four cylinder. I am a student who can’t afford another car right now and need desperately to drive. I am completely puzzled. I have replaced the calipers on the front and put on a rebuilt master cylinder. The master cylinder has three wires that connect to it on the side. What do these wires do since the cylinder has no moving parts. But, my problem is my brake pedal goes directly to the floor when I push on it. It makes a whoosh noise like air is escaping somewhere. I pump it and pump it and their is absolutely no pressue what so ever. I then get out and look at the fluid level and no fluid has ever left the reservoir. I used a sucton pump on it before I took the master cylinder off and was able to draw fluid to the caliper on the right front and rear sides. I figured that the other two lines where clogged because no fluid came through them when I used the vacuum pump. So, I replaced the left front line yesterday. I got in the car and pumped the brakes again and still the same thing, the pedal goes straight to the floor and the fluid doesn’t move at all. Shouldn’t I be getting some presure somewhere to the calipers. The brake fluid will not flow?
The wires are connected to a low fluid sensor.
Does the car have ABS brakes? Did you bleed all 4 brakes?
Not sure on this car. There is a pin/rod that connects the brake peddle to the cylinder. Perhaps it fell out when you installed the cylinder, you know the extra parts left over thing.
Is there a bleed valve at the master cylinder?
I not sure if you tried this: your car has a dual reservoir. It is separated in two sections: (it is a diagonal split system) right front and left rear uses one of them and left front and right rear uses the other. You should try to bleed it this way: get a couple of large brake fluid can at a parts store, ask a friend to help you to bleed the brakes, use a can half filled with clean brake fluid and a hose connected to the bleed screw. You will have to remove the wheels and jack the car, be careful so it will not fall on you - believe me it is not funny. Loose the bleed screw, ask him/her to push down and hold, close the bleed screw and ask him/her to let it go. Do it until all air is out. You should do it in this order: right rear brake, left front brake, left rear brake and then right front brake. See if this will help you. Those wires comes from a pressure switch that turns on a idiot light if a fault in one of the diagonal system happens. Post your results.
Did you bench bleed the master cylinder before installing it in the car? If not you need to do this before you go any further.