Symptoms of a Bad or Failing Vacuum Pump

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Cost of Replacing a Bad or Failing Vacuum Pump

Common signs include poor fuel efficiency, difficulty pressing the brake pedal, oil leaking under the engine, and the AC not working. Our certified technicians can come to you and diagnose the problem. You will receive a $30 credit towards any follow-up repairs that result from the diagnostic. Following are example prices for Vacuum Pump Repair. Click on the button below to get an upfront quote for your car.

Cars Estimate Parts Cost Labor Cost Savings Average Dealer Price
2013 GMC Savana 2500 $334 $172.77 $161.00 20% $420.02
2008 Volvo S80 $695 $624.86 $70.00 5% $732.36
2011 Ford E-250 $452 $262.78 $189.00 18% $553.03
2010 Audi A3 Quattro $393 $322.84 $70.00 8% $430.34
2011 Mercedes-Benz C300 $439 $347.84 $91.00 9% $487.59
2011 Jaguar XJ $594 $523.98 $70.00 5% $631.48
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How to Diagnose a Bad or Failing Vacuum Pump?

vacuum pump

An internal combustion engine running on unleaded gasoline builds up a tremendous amount of pressure inside the enclosed crankcase. This pressure is used to power multiple belts and pulleys ranging from alternators to AC units, but is released thanks to the use of a vacuum pump. A diesel engine on the other hand relies on vacuum pumps to provide power for other systems, most notably the brake system and in many cases, the air conditioning system. The vacuum pump operates continuously as each cylinder inside the engine continues to fire. When the vacuum pump goes bad or fails entirely, it can significantly impact the overall performance and operation of a vehicle.

Since the vacuum pump is always in use, the likelihood of experiencing some sort of mechanical failure or entire breakage is more likely on diesel engines that utilize this component. The most common cause of vacuum pump failure occurs due to broken belts, electrical problems inside the unit, or vacuum hoses that fail. On a gasoline powered vehicle, the vacuum pump tends to impact the emissions or exhaust system; however, if not properly maintained, it can cause significant damage to cylinder head components.

The pump operates constantly if the engine is on, so wear and tear will eventually cause it to fail. When this happens, you’ll notice a reduction in braking performance. If your vehicle uses the vacuum pump to operate the AC, you’ll also notice that you aren’t able to maintain a consistent temperature in the cabin.

Here are some common symptoms that hint towards having a bad vacuum pump for gasoline and diesel applications.

1. Poor fuel efficiency

When a vacuum leak exists, it’s most commonly caused by vacuum hoses that are broken, have faulty connections or the vacuum pump is not in operation. If you listen very carefully, sometimes you can hear a "hiss" sound that is the signal of a vacuum leak. However, the most common way to notice this is when the engine loses fuel efficiency. The reason for this is due to the fact that vehicle exhaust is delayed on exiting the combustion chamber. When there is a buildup of burnt fuel, the new fuel burns less efficiency. This condition will also reduce engine performance; but it really depends on the manufacture and use of the vacuum pump.

If you notice that you have poor fuel efficiency – in both gasoline and diesel engines, have your local ASE certified mechanic inspect your vacuum pump, hoses, and engine for any vacuum leaks.

2. Brake pedal hard to press

This symptom is common with diesel engines that use a vacuum pump booster to help improve brake performance. It's especially common on larger diesel semi-trucks and dual-tire configured rear-wheel drive trucks. When the pump begins to fail, it produces less suction which helps to provide pressure to the brake master cylinder and provides additional pressure inside the brake lines. Eventually the lack of pressure in the brake system works its way up to the pedal. If there is a lot of pressure, the pedal will be solid, yet very forgiving. When vacuum pressure is low, the pedal is rough and very difficult to press down and engage the brakes.

When you recognize this warning sign, don't wait to have this item fixed or examined by a professional mechanic. Have a certified diesel mechanic fix this issue as soon as possible.

3. Leaking oil under the side of the engine

Most vacuum pumps are located on the left or right side of the engine, typically closer to the brake master cylinder on diesel vehicles. The vacuum pump requires oil to maintain proper lubrication and to reduce internal temperature due to its frequent use. If you notice oil is dripping from the left or right side of your engine, it may be coming from the vacuum pump. Have a mechanic examine this problem regardless of where you might think the oil is leaking, as it can lead to major mechanical component failure if not fixed.

4. Air conditioning not working

If your AC unit stops working all of the sudden, it might be caused by a vacuum pump, especially in diesel applications. If you notice a problem with your AC unit, but it's been recently serviced, contact a local mechanic to inspect your vacuum pump for any issues.

The warning signs above are just a few of the potential symptoms of a bad or failing vacuum pump. If you experience any of these, make sure to contact YourMechanic, so one of our local ASE certified mechanics can arrive to your home or office to inspect your car, diagnose the precise problem and provide an affordable solution.

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YourMechanic Vacuum Pump Repair Service

Average Rating

4.7/5

Number of Reviews

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Duane

22 years of experience
323 reviews
Duane
22 years of experience
Duane showed up early, got the job done and saved me some money. I'll definitely be calling him again! Thank you!
2010 VOLKSWAGEN GOLF - VACUUM PUMP - ENCINITAS, CALIFORNIA

Patrick

30 years of experience
865 reviews
Patrick
30 years of experience
Patrick arrived early and completed work on my car in a professional & timely manner. He is very knowledgeable & found another issue that I will most definitely be requesting his service again to fix. Major plus was saving quite a bit of money, doing it at residence and being able to continue daily tasks without interuption.
2011 MERCEDES-BENZ C300 - VACUUM PUMP - DEL VALLE, TEXAS

Jacob

9 years of experience
119 reviews
Jacob
9 years of experience
Jacob is a pro. Took my car to the dealership to look at a couple things. They quoted me over $2700. Called Jacob to see if that sounded right. He went to work and sent me a quote. He did the research and found a better, more cost effective way to do the repairs. It allowed me to to get everything repaired and not have to worry. You can’t put a price on peace of mind. I’m done with dealerships.
2010 AUDI A6 QUATTRO - VACUUM PUMP - DALLAS, TEXAS

Paul

30 years of experience
67 reviews
Paul
30 years of experience
Would highly recommend. Paul is very professional and knowledgeable.
2007 VOLKSWAGEN PASSAT - VACUUM PUMP - RALEIGH, NORTH CAROLINA

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