Airing the fuel system of a diesel engine. Airing the fuel system of a diesel engine How to check the intake system for air leaks

Not only the maximum power of the engine depends on the composition of the air-fuel mixture (its “quality”), but, what is sometimes more important, its controllability - excess air entering the intake tract can cause the engine to stop at the most inopportune moment. Let's say you are driving from a secondary road onto a main road. We assessed the distance to the flow of cars moving along the main road - and when you try to “take off” the engine stalls... Damage to the car from a side impact may not be the most serious consequence in this case.
What may be the symptoms of air leaks in the intake manifold and “how to deal with them” is the topic of this article.

Minor “excess” air may not manifest itself in any way, since they are not capable of significantly changing the composition of the combustible mixture, and only engine diagnostics can identify them.
But with major damage to the intake tract, symptoms of air leaks may include:

The first symptom of air leaks in the intake tract is unstable engine idle.

unstable operation of the engine at idle, until it stops;
failures during acceleration, and at sharp pressing pressing the gas pedal, the engine may stall again, especially when the car starts moving;
possible promotion operating temperature engine due to its operation on too lean a mixture.

It should be noted that uneven engine operation is “smoothed out” at medium and high speed, we can only note a decrease in the traction qualities of the engine.

How can “extra” air enter the cylinders?

Excess air can enter the fuel mixture not only directly through a broken gasket intake manifold, but also through the parts associated with it. Let's take a closer look at possible places where the integrity of the intake tract for carburetor and injection engines separately.

Carburetor engine

Possible places for air leaks at the inlet

Possible “weak points”:

A common cause of air leaks is deformation of the carburetor “sole” when the carburetor is tightened on a hot engine.

carburetor gasket;
carburetor diaphragm. These are mainly the diaphragms of the starting device and the damper drive of the second chamber - not all models have the latter;
vacuum hoses for controlling the advance angle (goes to the distributor), for all kinds of pneumatic valves; also sometimes the carburetor fittings themselves are not tightly inserted into the body at the factory;
deformation of the “sole” of the carburetor; A very common cause of suction is caused by the fact that the carburetor is tightened on a hot engine.

Injection engine

Suction is possible through:

injector seals;
receiver gasket;

Generalization

In addition, for both types of engines, suction is possible through a damaged hose vacuum booster brakes, as well as through the seal of its valve (fitting), inserted into the amplifier housing. Moreover, many car enthusiasts ignore the fact that if configured incorrectly freewheel The brake light switch (“frog”) can disrupt the correct operation of the amplifier itself, as a result of which air intake from it will be “incorrect”, which will cause excessive air intake into the intake manifold. The correct setting of the “vacuum valve” is also influenced by the amount of protrusion of its rod from the body. The most unpleasant thing in this situation is that air leakage “through” the vacuum booster cannot be detected from the outside during inspection.

Troubleshooting

You can easily and clearly detect air leaks in the intake manifold using a smoke generator.

The most in an accessible way to detect air leaks in the intake manifold is a visual inspection. Cracks and breaks in air hoses can be seen with the naked eye. You can also check how tightly the parts are connected to each other. It often happens that during repairs, for example, the nuts securing the carburetor or other components were not properly tightened.
If there are no visible causes of malfunctions, then spraying “Quick Start” type compositions made on the basis of ether from a can along the joints of parts is very effective. The procedure must be carried out with the engine running. Ether that gets into the manifold through the cracks will cause changes in the operation of the motor - its speed should increase briefly.
Finally, the question of how to detect air leaks in the intake manifold is easy to resolve if you have a smoke generator. With its help, finding places of leakage does not present any special problems. Having “pumped” the intake tract with smoke, you can visually observe where the integrity of the intake system is compromised - in this case, it is better to use a blue lamp (flashlight) - in its light it becomes more noticeable.

Eliminating air leaks in the intake manifold

When repairing the intake manifold, do not apply force to the sensors - excessive force can damage them.

Repairs mainly come down to replacing gaskets, seals and vacuum hoses. Moreover, you should not restore cracked hoses with sealant - excess of it, if it gets into the air duct, can cause blockages.
When making repairs, remember not to put any force on the , trying to check if some of them are stuck. This is especially true for the idle air regulator - it is installed in the intake tract. By pressing on its core, you risk completely ruining the regulator, which is a stepper motor.
And finally - consider one more important point. Sometimes air leakage “from the side,” although it does not in any way affect the operation of the engine, can lead to very unpleasant consequences. We are talking about cases when air enters the manifold bypassing the air filter. For example, if that part of the filter housing from which air purified from dust enters the collector is split. It happens that a person drives for a long time with a significant crack in the filter housing or in the corrugated air intake hose from the filter to the housing throttle valve. The idle speed and engine power will be normal, but you risk greatly reducing the life of the engine itself.
One automobile magazine once published a note about an experiment carried out by a group of inquisitive people - they drove through the desert without air filter. The engine completely “ran out” without traveling even 100 km. Therefore, look carefully!

How to correctly identify the symptoms of engine air leaks and carry out a complete diagnosis? Similar questions may arise after a certain amount of mileage with the car, because the engine, being a very complex mechanism, is subjected to enormous load, as a result of which it wears out.

If you let these processes take their course, you can end up with a fairly large amount of money wasted on repairing or replacing the engine.

Symptoms of engine air leaks are most often unambiguous: a drop in power occurs. Some car owners experience a loss of power at low engine speeds (some at high speeds). It depends on the type of engine (diesel / gasoline), as well as a number of other reasons.

Detecting engine air leaks

It is not so easy to identify a leak. You need to start the procedure for searching for this phenomenon by inspecting the hoses and gaskets, including the cylinder block. Some auto repairmen complain that in their practice they have encountered air leaks even through the injector gaskets. Among the places that are least likely to allow suction, we can highlight the valves that ensure air recirculation in the car interior. So, you suspect that you have this problem.

Search is carried out by two common methods, which, naturally, are carried out in the engine compartment. The essence of the first method is to spray the engine hoses while the engine is running. plain water. According to the idea, if there is an air leak, when water gets into the desired hole, there will be a short-term decrease in engine speed.

The second method is similar in essence. Instead of water, you need to pour ether on the same hoses, in this case the engine speed will increase.

As you understand, there is no exact method for determining the presence of air leaks from an engine. A non-sealed system can bring a lot of headaches to the car owner, for example, on-board computer will show a lot of errors and will not help here.

By spraying, you can find the location of the problem, carefully monitoring the engine speed. Of course, this is a rather labor-intensive process (if you are not lucky enough to find a gap right away), but it will save you money from visiting a service station.

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A different approach to determining air leaks

An effective way to determine air leaks is to measure the level of vacuum in the intake system, i.e. in the behind-the-scenes space. Ideally, these indicators should be below 300 mmHg.

Measurements can be taken by removing the hose that connects to the valve, damper manager air circulation inside the car. The question immediately arises: what instrument to take measurements with?

If the problem is not resolved

You can try to solve the search problem using steam generators. By the way, this device perfectly helps to detect leaks and breakdowns in any devices that contain air. We close the throttle pipe with any plug and connect it to the intake manifold.

Any leakage will be easily detected by the smoke generated by the steam generator. In their work, professional auto repair shops do not use a steam generator, but

An air bubble entering a person's heart leads to death. Air entering the heart of the car - the engine - leads to less tragic consequences, but is also fraught with big troubles and can stop it forever.

Just like a normal person constantly monitors the condition of his body, a normal car enthusiast constantly monitors the “health” of his iron comrade. The “organism” of a car, of course, is less complex than a human one, but there are many reasons for various malfunctions and failures, especially if the car is no longer young.

This is despite the fact that such a problem as, for example, air leaks can also occur in a completely new car. Of course, this is rarely inherent in expensive modern foreign cars, but domestic cars Quite often they suffer from such a “disease”.

The cause of suction is often the units that supply the fuel-air mixture to the engine, which, of course, can affect its operation. For example, it may be that the car starts, but after some time it stops responding to pressing the accelerator pedal. Then, as a rule, the problem deepens, when the engine can only be started with large and repeated efforts from the starter.

If the car does not start at all, see if fuel is getting into the cylinders. This is quite simple to do - you need to see if there is at least a slight smoke from exhaust pipe when trying to start. Of course, it’s not easy to do this yourself, but anyone, even a child, can help with this.

A modern car is not just a means of transportation, but also a very complex mechanism, even a group of mechanisms, and therefore there can be many reasons for the disruption of fuel supply to the engine. The most common cause is a problem in the fuel supply line. This could be wear and tear on the hoses, a problem with the fuel pump, a filter with poor-quality or worn seals, or corrosion of the fuel pipes. This problem can unexpectedly appear after the car is repaired, when careless or simply unqualified “specialists” break the tightness of the connections of individual elements of the fuel system.

Air enters the engine cylinders in different ways. Possibly from the atmosphere, this occurs in cases where air can be sucked in from the outside, or perhaps penetration from the internal space of the engine. Be that as it may, in any case, this shows that there is a leak in the fuel system and this requires immediate elimination.

Air leaks are only the beginning of problems that can lead to engine failure. Air entering the combustion chamber does not allow the working mixture to fill the volume in the required quantity - the combustion time of the mixture increases and, accordingly, the engine loses power when trying to increase the load. At this time, the driver may notice interruptions in engine operation and dull sounds escaping from the exhaust pipe, and you may also notice that the engine is overheating too quickly. Overheating is the cause of ignition fuel mixture even before it enters the combustion chamber, and this will inevitably lead to engine breakdown if this is not responded to in time.

In the event of a malfunction, as usual, you can try to fix the problem on your own, but this is only if you have certain skills. If there are none, then it is better to contact specialists who will conduct a thorough diagnosis and competently repair the malfunction.

When a car, when starting from a stop (sharply), begins to choke for a second, and in some cases even stalls, this is 99% air leaks. Because excess air entering the engine cylinders causes abrupt and, as a result, difficult ignition. The engine runs rough and may stall at idle.

In this article we will learn to determine:

Symptoms of air leaks

Symptoms of engine air leaks are most often unambiguous:

Uncertain start in the morning.
Unstable idle– idle speed is constantly changing and below 1000 rpm. the engine may stall. On a car with a carburetor engine, the quality and quantity screw becomes insignificant for setting the XX mode since the air bypasses the XX channel.
Power drop- in the intake tract on systems with MAF () - low idle speed; on systems with a MAP sensor (absolute pressure sensor) vice versa - increased speed XX, lambda errors, lean mixture, misfire.
Increased fuel consumption- in order to start and continue driving, you need to constantly maintain high revs, while staying in a lower gear longer.

Air leak points

The main places through which suction can occur include:

intake manifold gasket;
throttle body gasket;
section of the pipe from the air filter to the throttle assembly;
injector O-rings;
vacuum hoses;
adsorber valve;
idle air control (if equipped).

Separately, it is worth considering the air leakage areas on carburetor engines- there are no electronics, and air can only be sucked into the vacuum booster or somewhere into the carburetor.

Choke points (carburetor)

The screw has the quality of the fuel mixture.
For the gasket under the carburetor - areas with soot are a sure sign.
Through a loose throttle valve.
Through the throttle axes.
Violation of the integrity of the throttle damper, economizer or starting diaphragms.

Air leaks in the diesel fuel system

In the fuel system diesel engine airing occurs, as a rule, due to a leaky joint between the low-pressure fuel system pipes (from the tank to the filter and from the filter to the injection pump).

Cause of suction on a diesel car

Air leaks in a leaking fuel system occur because atmospheric pressure higher than that created when the pump sucks diesel fuel from the tank. It is almost impossible to detect such depressurization by leakage.

On modern diesel engines, the problem of air leaking into the fuel system is much more common than on older diesel engines. All through changes in the design of the fuel hoses, since previously they were brass, and Now they make plastic quick releases, which have their own operating lines.

Plastic, as a result of vibrations, tends to wear out, and rubber sealing rings tend to wear out. This problem is especially pronounced in winter time on cars with mileage of more than 150 thousand km.

The main reasons for suction are often as follows::

old hoses and loose clamps;
damaged fuel pipes;
loss of seal at the fuel filter connection;
the tightness in the return line is broken;
The seal of the drive shaft, the axis of the fuel control lever or in the fuel injection pump cover is broken.

In most cases, something trivial happens aging of rubber seals, and the fuel system can become airborne if any of the branches, both forward and reverse, are damaged.

Signs of air leaks

The most common and common problem is that in the morning or after a long period of inactivity, the car stops starting quickly and you have to crank the starter for a long time (at the same time there is a little smoke coming from the exhaust - this will indicate that fuel is entering the cylinders). A sign of a large suction is not only a difficult start, but also when driving it begins to stall and stall.

This behavior of the car is due to the fact that the fuel injection pump does not have time to pass foam through itself only at high speeds, and at idle it cannot cope with the large amount of air in the fuel chamber. To determine that the problem in the operation of a diesel engine is associated precisely with air leaks, Replacing the standard tubes with transparent ones will help.

How to find a leak in a diesel fuel system

Air may be leaking in a connection, in a damaged tube, or even in the tank. And you can find it by elimination, or by applying pressure to the system to release it.

Most the best and most reliable way- find leaks by elimination: connect the diesel fuel supply to each section of the fuel system not from the tank, but from the canister. And check one by one - immediately connect to the injection pump, then connect before the sump, etc.

A faster and easier option to determine the location of the leak would be to apply pressure to the tank. Then, in the place where air is sucked in, either hissing will appear, or the connection will begin to get wet.

Air leak in the intake manifold

The essence of air leaks in the intake tract is that excess air that is not taken into account by the MAF or DBP sensor enters the engine along with the fuel, which leads to a lean air-fuel mixture in the cylinders. And this, in turn, contributes to improper engine operation.

Cause of air leaks

Mechanical impact.
Overheating (affects the elasticity of gaskets and sealant).
Excessive abuse of carburetor cleaning products (severely softens sealant and gaskets).

Most it is problematic to find the place where air leaks in the area of the gasket between the cylinder head and the intake manifold.

How to find air leaks in the manifold

On gasoline engines Air not taken into account by the sensors enters the intake manifold through leaks or damage to the air ducts, leaky injector seals, and also through the hoses of the vacuum brake system.

We've sorted out the standard suction points, now it's also worth figuring out how to look for air leaks. There are several basic search methods for this.

A simple cigarette smoke generator

DIY oil smoke generator

The easiest way to check if there is air leak in the intake tract after the flow meter– unscrew the air supply pipe together with the sensor from the air filter housing and start the engine. Then cover the assembly with the sensor with your hand and watch the reaction - if everything is normal, then the engine should stall, strongly squeezing the pipe after the air sensor. Otherwise, this will not happen and you will most likely hear hissing. If you cannot find an air leak using this method, then you need to continue your search using other available methods.

They often look for suction either by pinching the hoses or by spraying likely places with flammable mixtures, such as gasoline, carb cleaner or VD-40. But most effective method to find the place where unaccounted air passes through, is to use a smoke generator.

Search for air leaks

As a rule, problems with XX, as well as the appearance of a lean mixture error, occur only with strong suction. A slight leak can be determined by observing the fuel trim at idle and high speeds.

Checking air leaks by pinching the hoses

To find the place where excess air is leaking, we start the engine and let it run for a while, and at this time we keep our ears open and try to hear the hissing, and if we can’t detect it, then we pinch the hoses that go to the intake manifold (from the fuel pressure regulator, vacuum amplifier, etc.). When, after pinching and releasing, changes are observed in the operation of the engine, it means there is a malfunction in this area.

Also, sometimes used compressed air search method. To do this, you need to close the filter pipe with the engine off and pump air through any tube, having previously treated the entire intake tract with a soap solution.

Finding air leaks by pouring gasoline

How to detect leaks by spraying

The method of spraying the joints with some flammable mixture while the engine is running effectively helps to determine the place where air is leaking into the engine. This can be either regular gasoline or a cleaner. The fact that you have found a place where it is leaking will be indicated by a change in engine speed (whether it will fall or increase). You need to take the hot mixture into a small syringe and spray in a thin stream all the places where there may be leaks. After all, when gasoline or other flammable liquid gets into the place of a leak, it immediately seeps into the combustion chamber in the form of vapor, which leads to a jump or drop in speed.

When looking for suction, you should spray on:

Rubber pipe from the flow meter to the idle air control and from the IAC to the valve cover.
Connections of the intake manifold to the cylinder head (in the place where the gasket is located).
Connection between the receiver and the throttle pipe.
Injector gaskets.
All rubber hoses are connected with clamps (inlet corrugation, etc.).

Checking the presence of suction with a smoke generator

Few people have a smoke generator lying around in the garage, so this method of searching for leaks in the system is used mainly at service stations. Although, if in a garage conditions the suction could not be found using the methods discussed above, then you can make a primitive smoke generator, although the usual one also has a simple design. Smoke is forced into any hole in the intake tract, and then begins to seep through the holes.

A vacuum leak can cause a variety of drivability problems as it adds extra, unwanted air to the engine, displacing the air and fuel mixture. Modern engines internal combustion(multiport fuel injection) use intake vacuum to control sensors, actuators, and power brakes (on some vehicles). Older engines also use it to control some emission control devices and supply fuel to the combustion chamber.

So even a small vacuum leak or air leak can fool you and your car computer into believing that a particular sensor or system needs repair. You then start replacing components, hoping that you will solve the problem, but to no avail.

Often a vacuum leak will make an audible hissing sound, which will make it easier to find; other times, however, you won't hear anything. Automotive shops and service stations use special, expensive equipment to detect hard-to-detect leaks. But before you go to the store, you can apply simple methods, used to track the most common vacuum leaks.

This guide will not only help you find a vacuum leak or clogged vacuum hose, it will also give you useful tips for repairs and will also tell you what problems with engine operation may indicate a possible vacuum leak. So let's start there.

Throttle body and intake manifold gaskets can also develop leaks.

How to check for air leaks and troubleshoot a possible vacuum leak

Vacuum hoses are a common source of engine performance problems. After years of use, vacuum hoses become worn, hardened, splintered, or softened, and the vacuum tubes deteriorate, become brittle, and break, causing all sorts of engine performance problems.

So when you notice an engine performance problem and can't find the source, include diagnosing a vacuum leak in your repair strategy.

Depending on your car make and model, you may find different sensors and actuators that rely on a good vacuum source to operate. For example, some engines use a manifold absolute pressure (MAP) sensor that requires vacuum to measure outside air pressure.

A MAP sensor vacuum leak can affect engine spark timing, stability, and efficiency. A vacuum leak can also prevent the engine from opening, cause the engine to overheat, and increase harmful emissions. This type of leak can also affect the positive crankcase ventilation (PCV) system.

Air leak symptoms

Here is a list of performance issues to be aware of as they may be related to a vacuum leak:

Hard start
Low engine power
Mixture misfires
Poor fuel economy
Poor acceleration
Rough idle
High idle
The engine runs intermittently (as if coughing)
Poor brake performance (on vacuum power brakes)

Keep in mind that these symptoms are not exclusive to a vacuum leak. For example, a faulty EGR valve, poor compression, or ignition timing problems can also cause one or more of these symptoms.

Check the vacuum hose connectors for cracks that could cause a vacuum leak.

How to find air leaks and vacuum leaks

FINE. You have problems with engine operation and you want to check where the system is sucking air or losing seals, where to start?

First, find the vacuum chart for your vehicle. You can find a copy of the vacuum diagram in your vehicle's owner's manual, but most car manufacturers include a diagram in the engine compartment. Lift the hood and look around the front of the engine compartment to locate the sticker.

If you can't find it in your manual or in your engine bay, you can purchase one from your dealer service department. Another source is your vehicle's repair manual, which contains all kinds of useful information that you can use to service and troubleshoot many automotive systems. This way you will make a good investment.

A vacuum diagram shows the various vacuum controlled devices and their relationships. Newer car models display the similarities of components and their locations.

FINE. Now that you have a vacuum diagram for your vehicle, you can begin troubleshooting for a potential leak. However, even if you don't have a chart right now, you can still follow these steps.

(Note. If you are trying to detect a potential vacuum leak due to a trouble code you received after the Check indicator Engine, your car's computer may be adjusting the air/fuel ratio to compensate, so the engine may not sound as if it is having performance problems. If this is the case, disconnect the throttle position sensor [throttle body mounted] or oxygen sensor to force the computer to run the engine in "hard code" [open loop] mode so you can hear the engine - rough idle. This will make it easier to locate the source of the vacuum leak during diagnosis.)

If you suspect a specific device (or several), you can start with that device. Otherwise, follow the diagram and start checking each hose. If you don't have a diagram, check each vacuum hose as you move around the engine. Most vacuum hoses are thin and soft, except for those used on the brake booster, which are thicker and stronger in design, and possibly the PCV hose.

Fixing vacuum leaks requires a thorough visual inspection of the hose, checking that it is connected correctly and listening to the telltale hissing sound.

But the noise of a running engine can make it impossible to hear the hissing sound coming from a leaking vacuum hose or gasket. For this, you have two options: you can use a mechanic's stethoscope, which helps amplify the sounds in your ear, or you can use a length of hose for the same purpose.

How to Check Every Vacuum Hose

Follow these steps to inspect each vacuum hose, maintaining a reasonable distance from moving components during inspection:

Start the engine and let it idle. Place the transmission in Park (automatic) or Neutral (manual) and apply the emergency brake.
Make sure the hose is connected correctly and is not loose. When servicing or replacing a component, the hose can be easily damaged. You may need a small mirror and a flashlight to check hard to reach places, such as behind the intake manifold, throttle body, or exhaust manifold.
Disconnect and inspect both ends of the hose. If the inner end of the hose is torn, frayed, or expanded, cut off the damaged portion and reconnect the hose to the fitting.
Trace the length of the hose with your fingers to determine if there are any rough, hardened, split, softened, or areas that stand out from the overall background of the hose. Also, try to feel the vacuum in those rough or uneven areas.
Check that the hose is near or not touching a hot surface.
Also, check hose connectors, tees, and joints for cracks or looseness. Replace them if necessary.
Also check the hose for contaminants such as oil, coolant or other substances. Disconnect the hose from the device it connects to and check inside the device connector. If you find a foreign substance inside the hose, the contaminant may have entered the unit and may not be working properly. You may need to test the device for proper operation.
As part of your visual inspection, inspect the devices that the vacuum hoses connect to. Check the devices for damage such as cracks, dents, and loose parts. They can also create a vacuum leak. Squeeze the vacuum line leading to the device and spray it with soapy water and look closely to see if it is foaming somewhere, and if so, that is where the leak is.
If you find a hose that is soft, hardened, or damaged, replace it.

Replace the intake manifold gasket if a vacuum leak occurs.

Air leak in intake manifold symptoms

While you're more likely to encounter a vacuum hose leak, intake manifold gasket leaks can also occur. If the previous inspection does not indicate that anything is wrong, check the intake gasket between the manifold and cylinder head, as well as the base gasket located between the intake manifold and the throttle body or carburetor.

To check these gaskets you can use one of two simple alternative methods:

Soapy water in a spray bottle.
A mechanic's stethoscope or listen through a long hose by placing one end to the test site and the other to the ear

Any of these methods are good.

Apply emergency brakes.
Set your transmission to Park (automatic) or Neutral (manual).
Block the wheels to make them safer and prevent the vehicle from moving.
Start the engine and let it idle.
Use soapy water and spray a little around the intake manifold where it meets the cylinder head and around the base of the carburetor or throttle body. Don't forget to visually check the intake manifold itself for cracks and spray water in suspicious areas.
Listen for any changes in engine idle speed.
You may also see bubbles at the site of the vacuum leak.

Note. To use a hose (or mechanic's stethoscope), place one end of the hose over your ear and move the other end of the hose around the edge of the intake manifold gasket and carburetor or throttle body gasket. If there is an air leak, you will hear a hissing sound.

If you find a vacuum leak in the intake manifold or throttle body base, first try tightening the intake or throttle body mounting bolt:

Tighten the bolts gradually in a criss-cross pattern - when tightening the manifold, start at the center and work your way out.
Tighten the bolts to the torque specified in the vehicle repair manual using a torque wrench.
Check again for vacuum leaks.
If the leak is still present, you will need to replace the intake manifold gasket or throttle body gasket.
Follow the instructions in your vehicle's repair manual to replace any gasket.

Watch the video below to see the guy use water to diagnose a misfire on cylinder one.

Vacuum leak detection using water

Often, a thorough visual and manual inspection such as the one described above is sufficient to detect a vacuum leak. But not all the time.

Some components operating under vacuum may have internal damage (eg diaphragm rupture). And you cannot diagnose this type of damage by touch or sight.

So, if you suspect a vacuum leak but can't find the source, this is the next step in your troubleshooting strategy.

To do this, you need to use a manually operated vacuum pump. You can buy one at most auto parts stores or online. A vacuum pump helps troubleshoot emissions systems. But if you don't want to buy a tool right now, your local workshop can help you with this.

Follow the instructions included with your vacuum pump for the operating instructions and repair manual for your specific vehicle to learn how to troubleshoot the unit you need to check.

Sometimes you need to troubleshoot a device under certain operating conditions or in combination with another tool. While this type of troubleshooting may seem complicated, you don't need any special training. However, you still need to follow the tool's operating instructions and troubleshooting instructions in the repair manual.

Also follow these tips when using a vacuum pump:

Make sure the connection between the pump and the device is tight - use the correct diameter connector or hose for the connection.
Apply only the required amount of vacuum for the device being tested (usually 10 to 15 Hg, refer to repair manual).
The fewer connectors, adapters, and hoses you use to connect the hand pump to the device you want to test, the better.

You can use the fitting to repair small leaks in vacuum hoses.

Dealing with damaged vacuum hoses does not necessarily mean you need to replace them. Often the vacuum hose requires a simple repair that may take a couple of minutes or so.

You can repair a damaged end of a vacuum hose in a minute. In most cases, you can trim about an inch off the end and reconnect the hose.
Be careful when dealing with damage located between the ends of the vacuum hose. If you just need to repair a small hole of less than half an inch, cut out the damaged area and use a fitting to reconnect the two pieces.
To avoid confusion, repair one vacuum hose at a time. Some cars, especially Asian brands, come with multiple vacuum hoses, which can make repairs difficult when they are connected in various ways. In these cases, you can find 1-, 2-, 3-, 4-pin and elbow connectors to handle almost any kind of hose installation and repair.
Always mark hoses and their corresponding connectors or fittings so that repaired or new hoses can be reinstalled into the appropriate fittings.
If you find one or more disconnected hoses, use the vacuum diagram to reconnect the hose to the correct fitting.
After repairs, route and secure the vacuum hose away from hot surfaces and moving components.
Always replace the vacuum hose with the same diameter and length and for the intended application (PCV, brake booster or regular vacuum).

Categories:// from 09/13/2019