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Oil in brake booster line

Oil is coming in the brake booster from vacuum line

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Duplicate question.

Posted on Nov 01, 2012


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SOURCE: 1989 ford thunderbird std brake system vacuum booster install?

There are a Couple of Different Variations on the Boosters. Make sure that you have the Correct one First. If you do, Just work it, Some of the Rods are Removeable by the Way.

Posted on Jan 21, 2009

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SOURCE: I have a 94 v6 camaro and am missing a vacuum line

Sounds like, there is no power brakes if the hose is not connected to the brake booster. There should be a massive vaccuum leak in the engine. The brake booster vaccuum line is a major vaccuum. You should hear a hissing sound when engine is running. Find the hissing noise and replace as nessessary.

Posted on Jul 23, 2009

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SOURCE: Where can I find a picture of the brake booster

A good place to find reference material about certain model vehicles other than searching on the Internet is the public library. They usually have all the Chilton, Mitchell and Haynes manuals that you can browse or take home for free.

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Posted on Jun 20, 2010

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SOURCE: brake pedal is hard but brakes not very effective

Check the brake fluid it low or no brake fluid at the brake fluid got dried up or leaked out. Sounds like the power brake booster is bad, that is what the master cylinder is bolted too. There is a rubber hose that has a plastic valve in it were it snaps into the booster, Pull that rubber hose out of the booster and off of the engine, Now the end that you took off the engine. You should be able to **** through the line, but not be able to blow through it. If you can then replace the valve, It is a one way valve.
If that is all right then hook hose back up to the engine and start engine, You should hear a major vacuum leak at the valve end, put you finger over the valve and it should stop making noise and engine should smooth out. If it don't the rubber hose must be leaking or the tube on the engine were the hose hooks to is stoped up.
Also check the master cylinder if power booster is replaced. If the brake light is coming and going check the brake light switch. check fig for the internal assembly parts:-- bdea807.gif

To check engine vacuum, connect a vacuum gauge to the supply hose that runs from the intake manifold to the booster. A low reading (below 16 inches) may indicate a hose leak or obstruction, a blockage in the exhaust system (plugged catalytic converter, crushed pipe, bad muffler, etc.), or a problem in the engine itself (manifold vacuum leak, bad valve, head gasket, etc.).
The condition of the diaphragm inside the booster is also important. If cracked, ruptured or leaking, it won't hold vacuum and can't provide much power assist. Leaks in the master cylinder can allow brake fluid to be siphoned into the booster, accelerating the demise of the diaphragm. So if there's brake fluid inside the vacuum hose, it's a good indication the master cylinder is leaking and needs to be rebuilt or replaced. Wetness around the back of the master cylinder would be another clue to this kind of problem.
To check the vacuum booster, pump the brake pedal with the engine off until you've bled off all the vacuum from the unit. Then hold the pedal down and start the engine. You should feel the pedal depress slightly as engine vacuum enters the booster and pulls on the diaphragm. No change? Then check the vacuum hose connection and engine vacuum. If okay, the problem is in the booster and the booster needs to be replaced.
Vacuum boosters also have an external one-way check valve at the hose inlet that closes when the engine is either shut off or stalls. This traps vacuum inside the booster so it can still provide one or two power assisted stops until the engine is restarted. The valve also helps maintain vacuum when intake vacuum is low (when the engine is under load or is running at wide open throttle). You can check the valve by removing it and trying to blow through it from both sides. It should pass air from the rear but not from the front.
Replacing a vacuum booster is a fairly straight forward job. All you have to do is disconnect it from the brake pedal on the inside and unbolt the master cylinder. The pushrod that runs from the booster into the back of the master cylinder must have the specified amount of play.
You will typically find the power brake booster mounted on the firewall attached to the master cylinder. The master cylinder is connected to the brake pedal.
Thanks. keep updated for any more can rate this solution and show your appreciation.

Posted on Jul 15, 2010

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1 Answer

Oil in brake booster

The vacuum is created via a mechanical pump driven from the cam, Or a separate, electrical pump.

The only liquid I have ever found in any servo (booster) is brake fluid from a leaking master cylinder.
If the vacuum is low/absent, due to a faulty cam driven vacuum pump, and crankcase pressure rises, along with a faulty one-way valve in the vacuum plumbing, it's possible the oil could be forced into the servo housing, and operating the brakes would help it happen as the servo could act as a pump itself and draw oil from the engine.

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When your brake pedal is hard, you may need to check your brake booster and the vacuum line to the brake booster if their is sanction, if their is sanction in vacuum pipe to the brake booster you need to have your brake booster replaced.
You also need to check your vacuum pump and the piping.

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I have oil coming through the brake booster line.

The engine must have excessive blow by from worn rings or the PCV valve is plugged. They make a kit that keeps oil out of the booster it is a canister about the 2/3 the diameter of a coke can and about 1/3 the height. If you don't have one try finding one on an older GM car, they are all the same part. The filter goes in the large vacuum line to the vacuum brake booster.

Nov 01, 2012 | Cars & Trucks

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Why would I have plenty of vacuum at my brake booster line? But none in the smaller lines on my 1977 Mercedes 300D like the one going to my shut off valve. Rebuilt vacuum pump and the engine only has

You still have a leak somewhere or it is plugged up. The brake booster is not the culprit. Find the vacuum canister and trace from there checking each line.

Sep 10, 2012 | Cars & Trucks

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Where is the brake booster vacuum line on the 89 toyota camry?

Booster line will attach to back side (firewall side ) of booster chamber.

Should find a metal elbow coming out of the booster chamber that the vacuum line will slip over.

When you look at the booster chamber from the front, the location of the line should be at approx. 9 o'clock (as if looking at a clock dial)

Jan 24, 2011 | 1989 Toyota Camry

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Breaks wont pump up no air in line.will pump up when car is not running.start it and hardly no pedal


Dec 03, 2010 | 1999 Oldsmobile Alero

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We just changed the engine oil and now I have no power brakes??

Power brakes are vaccum operated so check the vaccum line to the brake booster.

Jun 03, 2010 | 2005 Dodge Grand Caravan

1 Answer

At times when brake is applied,engine dies and brake light comes on,and check engine soon light comes on. Engine will start right away,but service eng light stays on

It sounds as if the brake booster is leaking. When you press the brake pedal, vacuum is drawn from the engine supply, if the booster is leaking, it allows too much vacuum to leak, stalling motors & triggering sensors. There is a check valve located between the line that comes from the engine manifold over to the brake booster & that can also cause problems.

Plug that line & use your brakes, if it cures the problem, you've found your issue.

Other than that, if you have another vacuum leak, the use of the brakes could just make it so bad that it then triggers symptoms so you shold check your vacuum lines. Vacuum leaks can be identified by usiing a can of carb. cleaner with a nozzle, spraying a small amount in bursts near vacuum lines, connections, and plugged lines. If there is a leak, the engine will stall or slow when it draws in the carb cleaner and you should be able to identify where the leak is. Go slow, spray only a little at a time & allow it to dissipate as it is a flammable product.

good luck

Feb 15, 2010 | 2001 Nissan Sentra

1 Answer

Replaced brakes and rotors 300 miles later brake light come on

check master cylinder around vacuum booster for fluid leak .also if pedal is stiff it could be vacuum to booster or booster itself..master cylynder connects to split block of brake lines,there should be a sensor on that block..see if connected good,, chris

May 07, 2009 | 2006 Nissan Xterra

3 Answers


Most likely your vacumn power brake booster has failed. It is not rebuildable. You will need to buy a new one.

Jun 11, 2008 | 1994 Chevrolet Corvette

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