How do I repair a brake booster motor

If the brake booster on your vehicle requires replacement and your vehicle is within the indicated time/mileage limitations, Lincoln Motor Company has authorized your dealer to replace the brake booster free of charge (parts and labor). This is a one-time repair program.

SERVICE BRAKE BOOSTER
Refer to Brake Warning System Description and Operation in Hydraulic Brakes

SERVICE BRAKE BOOSTER
The SERVICE BRAKE BOOSTER message will be displayed when the supplemental brake assist signal circuit is toggled at 1.0 Hz with a 50 percent duty cycle. This message is also displayed if the instrument panel cluster (IPC) does not see an alive and well signal at key on. When this message is displayed it indicates a problem with the SBA and should be serviced or replaced.

How do the power brakes work ? Good .?

Service Brake Booster Message Displayed
Step
Action
Yes
No
Schematic Reference: Brake Warning System Schematics
1
Did you review the Brake Warning System Description and Operation and the Brake Assist System Description and Operation and perform the necessary inspections?
YES - Go to Step 2
NO - Go to Symptoms - Hydraulic Brakes
2
Start the vehicle.
Is the REDUCED BRAKE POWER message displayed for 1 minute before the SERVICE BRAKE BOOSTER message is displayed?
YES - Go to Step 3
NO - Go to Step 4
3
Perform the Brake Assist System Diagnosis
Did you find and correct the condition?
YES - Go to Step 12
NO - Go to Step 11
4
Disconnect the Supplemental Brake Assist connector.
Test the ignition 1 circuit for an open or a short to ground.
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES - Go to Step 12
NO - Go to Step 5
5
Test both ground circuits for opens.
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES - Go to Step 12
NO - Go to Step 6
6
Test the engine on signal circuit for an open or a short to ground.
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES - Go to Step 12
NO - Go to Step 7
7
Test the vehicle speed signal circuit for an open.
Did you find and correct the condittion?
YES - Go to Step 12
NO - Go to Step 8
8
Test the supplemental brake assist signal circuit for an open or a short to voltage.
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES - Go to Step 12
NO - Go to Step 9
9
Connect the supplement brake assist connector.
Disconnect the instrument panel cluster connector.
Connect a DMM from battery positive voltage to the supplemental brake assist signal circuit.
Turn the ignition to the RUN position while observing the DMM.
Did the DMM flash battery voltage?
YES - Go to Step 11
NO - Go to Step 10
10
Replace the Supplemental Brake Assist pump motor assembly Refer to Power Brake Booster Auxiliary Pump Replacement .
Did you complete the replacement?
YES - Go to Step 12
--
11
Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.
Did you complete the replacement?
YES - Go to Step 12
--
12
Start the engine.
Does the Service Brake Booster message stay on?
Go to Step 2
System OK

you must have a vacuum leak at booster or the line going to it. This will cause engine to not start and no power brakes (hard pedal).

LEARNING ABOUT YOUR BRAKE SYSTEM
The hydraulic brake booster on a late model Mark VII and early Continentals, is very different from most. It is equipped with something known as a "TEVES" brake system. I'll attempt to teach you what does what and why, so you won't spend a ton of money just because you and maybe your mechanic aren't familiar how it works. The way its always been is,..."if you don't understand it...replace the whole thing"! The problem with using this technique is, unless you want to spend $2K for the whole thing, your going to be buying a used system....which may not be a whole lot better than the one you have now.
The main parts in the system that we will discuss include an ACCUMULATOR, a HYDRAULIC PUMP, a hydraulic pump RELAY, and a PRESSURE SWITCH. These are the key players in this operation.

THE LOCATION OF THESE PARTS ARE AS FOLLOWS:
HYDRAULIC PUMP MOTOR= Underneath the brake assembly (2 pin connector) Hydraulic pump motor
RELAY = On the drivers side strut tower
PRESSURE SWITCH = 5 pin connector facing the # 7 or 8 spark plug(drivers side)
ACCUMULATOR = Round black ball on the drivers side

WHAT THESE ITEMS DO:
HYDRAULIC PUMP MOTOR is an electric hydraulic pump used to "boost" pressure for the brake assembly. This pump is $900 new!
hydraulic pump motor RELAY is just what its sounds like. It gives the hydraulic pump motor power to come on.
PRESSURE SWITCH is the "brains" in the system. It senses how much pressure is "on line", and when the system needs more pressure, it tells the relay to "power up" the hydraulic pump motor.
Another one of its jobs is to turn on the RED BRAKE LIGHT, then the ANTI-LOCK lights to alert the driver that the pressure is dangerously low. (The reason the anti-lock light comes on, is because the ABS cannot fuction if theres a problem with the manual brakes)
ACCUMULATOR stores energy or pressure like a reservoir. Its there so the hydraulic pump motor only has to come on every 3rd or 5th time. Its design is more complicated, but basicaly the same principle as an air tank on a compressor.

WHAT NORMALLY HAPPENS:
Whats usually happens is, in time, the accumulator gets weak with age and can't hold the pressure like it was designed too, and therefore, the hydraulic motor comes on everytime the brakes are applied....rather than every 3rd or 5th time. This means all these parts are working 3 or 5 times more than they were designed to. This puts an extreme amount of pressure on an already old system.
What we know from this is, the accumulator needs replacement because its what started all this, but now the pressure switch and relay needs replacement also because it has worked it to *****.
NOTE: always replace the relay when replacing the pressure switch. The relay came on everytime the pressure switch told it too, so if ones worn out....the others not far behind!

Instructions

• Mark the location of all of the brake lines running into the brake master cylinder using masking tape and permanent marker.
  
• 2Slide the tube nut wrench over the brake line running to the brake master cylinder. Orient the wrench so that it fits over the end of the tube nut.
  
• 3
  
• Turn the nut counterclockwise to remove it from the master cylinder.
  
• 4Pull the brake lines out of the master cylinder.
  
• 5Remove the bolts holding the master cylinder to the brake booster.
  
• 6Remove the mounting bolts on the brake booster that secure it to the firewall.
  
• 7Remove the cotter pin running through the head of the pin that connects the brake booster diaphragm to the back of the brake pedal with a pair of pliers.
  
• 8Remove the brake booster diaphragm pin.
  
• 9Remove the bolts inside the driver foot well that secure the brake booster to the firewall.
  
• 10Install a new power brake booster. Installation is the reverse of removal
  

The power brakes vacuum booster... may have a vacuum leak. you can check it with an engine vacuum meter, or remove the rubber hose from the booster and plug it.. and see if the engine changes pase, idle smooths out, revs a bit higher, etc. noticeable change in engine idle would confirm a leak.

Yes a hard pedal is the symptom.

LEARNING ABOUT THE "TEVES" BRAKE SYSTEM
The hydraulic brake booster on a late model Mark VII and early Continental, is very different from most. It is equipped with something known as a "TEVES" brake system. I'll attempt to teach you what does what and why, so you won't spend a ton of money just because you and maybe your mechanic aren't familiar how it works. The way it's always been is,..."if you don't understand it...replace the whole thing"! The problem with using this technique is, unless you want to spend $2K for the whole thing, your going to be buying a used system....which may not be a whole lot better than the one you have now.
The main parts in the system that we will discuss include an ACCUMULATOR, a HYDRAULIC PUMP, a hydraulic pump RELAY, and a PRESSURE SWITCH. These are the key players in this operation.

THE LOCATION OF THESE PARTS ARE AS FOLLOWS:
HYDRAULIC PUMP MOTOR= Underneath the brake assembly (2 pin connector) Hydraulic pump motor
RELAY = On the drivers side strut tower
PRESSURE SWITCH = 5 pin connector facing the # 7 or 8 spark plug(drivers side)
ACCUMULATOR = Round black ball on the drivers side

WHAT THESE ITEMS DO:
HYDRAULIC PUMP MOTOR is an electric hydraulic pump used to "boost" pressure for the brake assembly. This pump is $900 new!
hydraulic pump motor RELAY is just what its sounds like. It gives the hydraulic pump motor power to come on.
PRESSURE SWITCH is the "brains" in the system. It senses how much pressure is "on line", and when the system needs more pressure, it tells the relay to "power up" the hydraulic pump motor.
Another one of its jobs is to turn on the RED BRAKE LIGHT, then the ANTI-LOCK lights to alert the driver that the pressure is dangerously low. (The reason the anti-lock light comes on, is because the ABS cannot fuction if theres a problem with the manual brakes)
ACCUMULATOR stores energy or pressure like a reservoir. Its there so the hydraulic pump motor only has to come on every 3rd or 5th time. Its design is more complicated, but basicaly the same principle as an air tank on a compressor.

WHAT NORMALLY HAPPENS:
What usually happens is, in time, the accumulator gets weak with age and can't hold the pressure like it was designed too, and therefore, the hydraulic motor comes on every time the brakes are applied....rather than every 3rd or 5th time. This means all these parts are working 3 or 5 times more than they were designed to. This puts an extreme amount of pressure on an already old system.
What we know from this is, the accumulator needs replacing because it's what started all this, but now the pressure switch and relay needs replacement also because it has worked overworked.
NOTE: always replace the relay when replacing the pressure switch. The relay came on every time the pressure switch told it too, so if one is worn out....the others not far behind!

CHECK POWER BRAKE BOOSTER.WITH ENGINE OFF.DEPRESS BRAKE PEDAL SHOULD BE FIRM.NOW START THE ENGINE BRAKE PEDAL SHOULD DROP A LITTLE AND HOLD IF BRAKE GOES TO THE FLOOR POWER BOOSTER COULD BE BAD.I STILL SAY YOU HAVE AIR IN BRAKE SYSTEM.YOU NEED TO BENCH BLEED BRAKE MASTERCYLINDER AND BLEED FRONT CALIPERS AND REAR BRAKE CALIPERS. BY YOUR CAR BEING ABS BRAKES SYSTEM BEST TO LET DEALERSHIP FIX BRAKES. THEY HAVE TO USE DIAGNOSTIC EQUIPMENT TO RESET ABS BRAKE HYDRALIC CONTROL UNIT AND PRESSURE BLEED THE BRAKE SYSTEM. IF BLOWER MOTOR KEEP RUNNING YOU HAVE FAULTY BLOWER MOTOR RELAY.IF BLOWER MOTOR HAS ONE SPEED CONTROL.YOUR BLOWER MOTOR RESISTOR BAD OR AC AND HEATER CONTROL SWITCH IS BAD.

Does it have a hydroboost brake booster? Is the belt still on the p/s pump? Have you checked the power steering fluid level? If yes and good to all, replace the Power steering Pump.