The vacuum pump is one of the most important systems in a vehicle. If it leaks, it can cause big problems. If you’re not sure if your pump is leaking, it’s a good idea to learn how to find and fix vacuum leaks. We can help you with that.
The goal for today is to understand the causes of vacuum leaks, identify early symptoms, learn detection methods, and get some tips on how to fix them.
How to Find & Fix Vacuum Leak
Let’s start with the common reasons why it even happens
So, What Are the Common Causes of Vacuum Leak?
- The brake booster is completely damaged.
- The positive crankcase ventilation system has worn out rubber and plastic parts.
- Intake snorkel installation was done improperly.
- Gaskets and intake manifold gap sealing O rings shirking.
- Carbon buildup causes the EGR to stick open.
Identifying Early Vacuum Leak Symptoms?
A vacuum leak causes the engine light to come on. Of course, it is not the only cause behind but one of the reasons. Hooking it on a reader and communicating with the onboard computer of the vehicle will be able to specify whether a vacuum leak is an actual cause.
Vacuum leaks don’t allow fuel to easily move into the engine. So, you will have a hard time accelerating. With pressing it down quite hard, if it still does not accelerate the way it used to, this can be a sign of a vacuum leak.
Vehicle idling higher than usual is also a sign. The sound will feel different as well. When not in motion, the rpm will be high when running.
Sudden stalling of vehicles also indicated extreme vacuum leaks. And this can even damage the engine terribly.
Vacuum Leak Detection Methods You Can Try
Let’s walk through 3 methods that work fabulously for detecting a vacuum leak.
The Direct Way
Find inside the service manual or engine bay placard and you will see the vacuum hose diagram. Find out where the ends of vacuum lines are. All lines must connect with the right fitting, have enough bend to grip the stud, and the plastic fitting is fine.
Now if the car is pretty old and so, lines are quite hardened, those will need replacement. Direct detection often means simply getting all the lines, as well as junctions, replaced.
Because they have not been replaced in a decade probably and a half dozen leaks can be residing here that are so small that you just canâ€™t detect each individually.
Using The Carb-Cleaner Way
Old school mechanisms are used to follow this technique. You need to:
- Get the engine in open loop mode by pulling the wire on the throttle position sensor.
- Let the engine idle once you turn it on.
- On the suspected leak, spray some aerosol carb cleaner.
If there is a leak it should suck the combustible carb cleaner. And the engine would start to idle speed momentarily. In case of a misfire, itâ€™ll go through all cylinders. You want to use short and direct puffs.
Keep In Mind â€“ You should be very careful with using carb cleaner because it can flare up if thereâ€™s any ignition source. And you donâ€™t want to lose your eyebrows.
Now if that sounds too hazardous, and you are wondering what can I spray to check for vacuum leaks instead of a carb cleaner, then just use the unlit propane torch, it is a better alternative.
A Method That Pros Usually Use
Anyone curious about how to find a vacuum leak with a smoke detection system. These cost quite a lot, around 1000 bucks so most professionals will use them. However, among all the testing systems for leak detection, the Redline Detection’s Smoke Pro system is the cheapest good one.
You have a button for a smoke with these and by pushing it a thick white smoke gets into the intake system as well as vacuum lines. The pressure that it produces is high enough to detect the leaks.
How to Fix Vacuum Leak?
Once you are done with figuring out the affected areas, fixing the leak should look something like this.
Get a high-grade sealant for dealing with the detected holes. Make sure you clean the surface of the hose, which is usually the place that gets affected by these weak spots.
If you don’t want to use a sealant, super glue patching shall work as an alternative. Though it’s not going to last you a long time. Especially if the area is close to heat exposure, the glue will melt and you will be left with leaks again.
If you find out the holes are pretty huge, so much that sealant wonâ€™t be enough to make things work, it is best to go for replacement.
Also, in case of having too many leaks. It is impractical to seal a huge number of leaks, as that will take a lot of time and effort. So then, replacing the hoes might be a better choice.
Once you sort out these steps, the leakage issue should be gone for good. Turn your vehicle on and do a test driving to check if the malfunction you were experiencing beforehand is still there. Hopefully Not!
Frequently Asked Questions
Is a vacuum leak expensive to fix?
If you are stressing over how much it costs to fix a vacuum leak, don’t! Because usually, it is pretty cheap. You just need sealants or glue to fix the leaks. Unless the whole system needs replacement. Then it is a different matter.
Can you drive with a vacuum leak?
Well, driving with a vacuum leak is possible but not recommended. You’re doing more damage to the vehicle. Also, the brake pedal will feel hard to press, sudden stalling, and the lights of the engine turning on. All of that would just make it hard for you to drive in peace. Also, it is not safe at all!
And that were our thoughts on how to find and fix vacuum leaks. Hope this guide was able to give you some insight. Wishing you all the best in sorting out the problem and coming out of this situation. See you on another similar piece soon, take care!