73 Charger w/power brakes
- Thread starter Randy73
- Start date
roadrunnerman
Well-Known Member
is there any leakage that you can see outside or under the dash it might be just a bad seal for the rod going into your booster.
74sundance
Well-Known Member
My money is on your master cylinder if you don't have any leaks or low fluid issues.
If you pressed the break and it stuck to the floor but didn't apply the breaks at all then you either have a break fluid leak/no fluid or a blown Master Cylinder.(Look for fluid leaking where the break pedal rod go's threw the fire wall into the back side of the booster and or where the master bolts to the Booster)
If you press the break and it applies like normal but won't return then:
* *The vacuum booster is a very simple design.It needs a vacuum source to operate. In gas cars, the engine provides a vacuum for the boosters.Because diesel engines don't produce a vacuum, diesel-powered vehicles need to use a separate vacuum pump as do some beefed up Gas motors.
On cars with a vacuum booster, the brake pedal pushes a rod that passes through the booster into the master cylinder, actuating the master-cylinder piston. The engine creates a partial vacuum inside the vacuum booster on both sides of the diaphragm. When you hit the brake pedal, the rod opens a valve, allowing air to enter the booster on one side of the diaphragm(the fire wall side) while sealing off the vacuum. This increases pressure on that side of the diaphragm so that it helps to push the rod, which in turn pushes the piston in the master cylinder.
As the brake pedal is released, the valve seals off the outside air supply while reopening the vacuum valve. That restores vacuum to both sides of the diaphragm, allowing everything to return to its original position.
But with this your breaks will still be on/locked up.
Normaly if your booster isn't working you would have a very hard pedal and wouldn't be able to stop as easily.
So if you have low Vacuum, a leak or faulty valve your booster wont work..
If you pressed the break and it stuck to the floor but didn't apply the breaks at all then you either have a break fluid leak/no fluid or a blown Master Cylinder.(Look for fluid leaking where the break pedal rod go's threw the fire wall into the back side of the booster and or where the master bolts to the Booster)
If you press the break and it applies like normal but won't return then:
* *The vacuum booster is a very simple design.It needs a vacuum source to operate. In gas cars, the engine provides a vacuum for the boosters.Because diesel engines don't produce a vacuum, diesel-powered vehicles need to use a separate vacuum pump as do some beefed up Gas motors.
On cars with a vacuum booster, the brake pedal pushes a rod that passes through the booster into the master cylinder, actuating the master-cylinder piston. The engine creates a partial vacuum inside the vacuum booster on both sides of the diaphragm. When you hit the brake pedal, the rod opens a valve, allowing air to enter the booster on one side of the diaphragm(the fire wall side) while sealing off the vacuum. This increases pressure on that side of the diaphragm so that it helps to push the rod, which in turn pushes the piston in the master cylinder.
As the brake pedal is released, the valve seals off the outside air supply while reopening the vacuum valve. That restores vacuum to both sides of the diaphragm, allowing everything to return to its original position.
But with this your breaks will still be on/locked up.
Normaly if your booster isn't working you would have a very hard pedal and wouldn't be able to stop as easily.
So if you have low Vacuum, a leak or faulty valve your booster wont work..
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