Vacuum lines – Information, common issues and fixes

We're an affiliate
We hope you like our recommendations! Just so you know, we may collect a share of sales or other compensation from the links on this page. Thank you for using our links, it is much appreciated.

Vacuum lines play an important part in your cars vacuum system. However, they are prone to damage or failure. Take a look at our vacuum lines guide for information, common issues and vacuum line fixes.

The vacuum system in your car plays an important role in supplying negative pressure to systems within your vehicle that need it. While it has a supportive role, it is important that components of this system are maintained for optimum function of other components.

We are going to discuss the connective component of this system i.e. the Vacuum lines or hoses: common issues you may experience with failing hoses, signs you should look out for when your hoses fail, their effect on your vehicles function and what you should do when you experience vacuum hose problems. Read on for more information on vacuum lines.

A crash course on vacuum lines

In case you’re not sure what vacuum lines are and why they are so important, don’t worry you are not alone. The vacuum hose alternatively known as vacuum line or vacuum tube is the connection that directs the manifold vacuum to the rest of the vehicle.

The manifold vacuum is the partial vacuum inside the intake manifold created by piston movement. During intake or induction strokes, this partial vacuum is created and maintained by restricted air flow.

This vacuum is a natural byproduct that is harnessed to operate all sorts of systems on your vehicle. The vacuum hose will connect to various systems on the vehicle and supply them with any negative pressure they may need.

A solenoid or valves is put in place to help control or adjust the amount of vacuum supplied to all the different systems. Different sensors and actuators that help run your vehicle or provide input when your vehicle reeds it rely on this vacuum provided

Common issues with Vacuum lines

The biggest issue with vacuum lines is LEAKS. There are many reasons you might experience leaks within your system. These rubber tubes have a tendency to get dry and brittle. Overtime, they may break, causing leaks within your system. In some cases chaffing or tubing wear triggers the hose to leak.

P.S sometimes hot and dry weather accelerates general deterioration of vacuum hoses.

Apart from degraded vacuum lines, there are other components within the vacuum system that contribute to you experiencing leaking. Let’s review some of the other common causes of leaks.

Intake snorkel

The rubber or plastic material that connects the engine intake to the air filter box is prone to cracks. Like with a torn or degraded hose, the only fix is a replacement. Apart from wear and tear, improper installation of the intake snorkel will lead to leaking.

Intake manifold and gaskets

The intake manifold is usually made of plastic and prone to warping often due to aging. The gaskets and rings which are useful in sealing the gaps within this system are prone to hardening and shrinkage.

The result of either warping or hardening is leaks, a driver’s worst nightmare when it comes to vacuum lines. In addition to warping or hardening, these parts are also prone to cracking and even breaking off.

Brake booster

This is the part installed between the brake pedal and the master cylinder. Usually, a leak within the brake booster will equal a vacuum leak.

Luckily you can identify a leaking problem from your brake booster because of the hissing sound that comes from the pedal area. Leaking within the booster is quite sensitive and cause for concern. In fact, the Jeep Grand Cherokee model between 2011-2014

Signs of faulty Vacuum lines

Because the vacuum lines supply much needed vacuum to various systems, a break or degradation of this tube means not enough vacuum reached the destination systems.

Without required negative pressure, you may notice performance issues with your vehicle. Some of the most common symptoms of a leaky vacuum hose include the following.

Check engine light comes on

Signs of faulty Vacuum lines

The efficient ECU built into many vehicle systems allows you to monitor individual components of your vehicle. In the event that you’re experiencing leaking or vacuum hose failure, the check engine light will come on and notify you of an existent problem. The best course of action is to have these codes professionally read and fixed to avoid further harm.

You engine will not start

This is often a result of leaking vacuum hoses. If they leak significantly, then the motor will completely shut off causing your engine not to start. However, many cars have sensors within their combustion engines that have an inbuilt warning system for changes in pressure within the chamber.

Engine runs weird

You may notice you engine run very rough. This is yet another effect of failing vacuum lines. Running rough includes any misfires or even inconsistent RPM.


These often occur when the electronic timing system fail to synchronize spark plug trigger times. Another cause for backfires could be the increase in combustion chamber pressure, typically controlled by vacuum lines. Backfires are great indicators for car problems. When you experience them, you must have your car thoroughly inspected for any underlying issues.

What else should you be on the lookout for?

Apart from the side effects of leaking on your engine, there are other ways you can diagnose damaged or worn vacuum lines, including.

Sounds or noises

You will experience hissing sounds coming from the engine or brake compartment while the car is running.

Power loss and fuel economy issues

One major signs that your vacuum system might have issues will be loss of power. Leaks often create power loss which in turn affects your fuel efficiency.

Issues with acceleration

Some drivers may notice the idle speed of their vehicle is faster than what it usually is.

Will a vacuum leak affect your engine?

Like we discussed above, the leaks play a big role in influencing your vehicles performance. To answer, yes, a leak will affect your engine but not in the ways you might imagine. Sure the overall performance of your vehicle will suffer but a vacuum leak will not permanently damage your engine.

However, this doesn’t mean you should prolong a leak if you discover or suspect one. Because the hose is damaged, the leak will only get worse. Continues use with a leaky hose will reduce your engine’s combustion effectiveness and possibly obstruct fuel delivery. This will only add stress to your components.

In the event you experience a leak, you should visit your mechanic for a replacement or make the replacement yourself.

Finding and replacing a leaky hose on your Jeep

Troubleshooting and fixing a leaky hose is one of the simple car repairs that anyone can perform. To start, you will locate the manifold vacuum in your car. If you do not know what it looks like, check your user manual for some assistance. Then carefully inspect the hoses for any leaks.

Many hoses should be soft and in good condition. Ensure to check the connecting ends and confirm that the entire hose is in good condition. A thorough inspection both visual and by hand is necessary to eliminate chances of experiencing leaky vacuum hose related issues.

In the vent that you find a leak, the best possible solution is to replace the leaky hoses and install new ones as a replacement.

What happens during a vacuum line replacement at a shop?

  • The mechanic will identify the broken or degraded vacuum hose
  • Next, they will remove the hose from its various connections and replace it with a new undamaged vacuum hose.
  • Once all the connections have been mad and the vacuum hose installed, the mechanic will start the engine to confirm that you no longer have leaks.

Leak detection methods

If you do not own a diagnostics device but wish to inspect your hoses for leaks, then there are many ways to do so.

First is the old smoke method where using automotive some, which comes in a can. Once the intake manifolds take in the smoke, you only need to insect the rest of the system for leaking smoke.

Apart from smoke you could use soapy water. This method not only helps detect leaks but also will help you identify exactly where these leaks are.  However, you will have to inspect your hoses before hand and highlight the areas you suspect of leaking. Afterwards, using the soapy water method, you can zero in on these suspected areas and confirm that they are truly problematic.

Driving with leaky hoses

First of all, your systems aren’t going to operate on optimum with a leaking vacuum hoses. You might experience some of the problems we discussed above, which aren’t all that great. Power loss to your engine might be unsafe especially if the leak continues to increase as you drive. It is advisable that you have your vacuum lines replaced instead of driving around with problematic leaking.

In addition to creating unsafe driving conditions, leaking vacuum hoses might cost you in fuel. Remember, power loss equals poor fuel economy. Meaning, you will have to spend more to fuel your vehicle than you usually would.

Final Word

Vacuum hoses are an important part of the vacuum system that are prone to wear and tear. This could lead to leaking and spell trouble for your car. It is essential to always have your hoses in good working condition and supporting other systems as they need to. If you experience bad or failing hoses, it is necessary to have them fixed as they could affect other systems working properly.

Default image
Steven Reilly is a qualified mechanic and his passion for cars goes beyond just the technical aspects. He is also an amateur racer and all round car enthusiast. When he is not driving them, he can often be found in his garage under the hood of a rare model. Steven Reilly has lost track of the number of hours he has spent setting up his fine collection of rebuilt models. He believes that cars can provide a constructive and fun opportunity to teach the youth important life skills. In line with this, he is developing a community outreach program, potentially dubbed ‘Cars for change'.
Articles: 396
***** Conversion.Ai Check Out a 5 Day Free Trail Write superb non-plagiarized content. *****