Bleeding trapped air from the fuel system is an important part of taking care of your engine. Here you may ask, “ where is the bleed screw on a diesel engine?”
Loosening the bleed screw is the precondition to continue bleeding for breaking the airlock. So, you must know its position.
Read the article to know your answer. You will also know the process of bleeding your diesel engine.
Where Is The Bleed Screw on a Diesel Engine?
The position of the bleed screw depends on how many bleed screws your motor has. Depending on how big the motor is, there may be more than one.
Generally, they are on top of the fuel filters that are built into the engine.
How to Bleed a Diesel Engine
Step 1: Find The Leak
Before you can get the air out of the system, you have to figure out how it got in. Never let a diesel engine run dry, as this will always cause an airlock.
Air leaks usually happen when the fuel filter is changed, but not in this case. You can stop this from happening by filling the new filter with fuel and adding more as it is used up.
You should also put fuel on the inside of the gasket before installing the filter.
Check for leaks at the connection points and along the fuel line itself if you’ve done everything correctly or haven’t changed the filters in a while.
After you’ve identified and corrected the issue, you’re ready to bleed the diesel engine’s fuel system.
Step 2: Loosen The Bleed Screw, Fuel Return Pipe Bolt, And Air Vent
Use a screwdriver to loosen the air bleed screw on the top of the fuel filter canister. Use a wrench to loosen the bolt on the fuel return pipe at the last injector before the pipe goes back into the fuel pump.
Move the lever on the hand pump until the fuel coming out of the pipe has no air bubbles. Use a wrench to make sure the fuel return pipe bolt is tight.
Use a screwdriver to loosen the air vent screw on the injector pump. Move the lever on the hand pump until the fuel coming out of the pipe has no air bubbles.
Move the lever on the manual lift pump until there are no air bubbles in the fuel coming out of the vent. Use a screwdriver to make sure the vent screw is tight.
Step 3: Find The Lift Pump And Fuel Filter
They are connected to the engine. If they are not, try following the fuel line or looking in the owner’s manual.
It’s important to remember that not all engines need to have the injector pump bled. Some bigger engines only need the secondary filter and injectors to be bled.
Step 4: Turn the manual fuel pump primer on
Find the fuel pump lever or plunger to know how to prime a diesel engine. Your fuel lift pump will be connected to the primary fuel filter and mounted on the engine.
Start pumping the lever or plunger and watch the bleed screw. As the air leaves the system, you will see bubbles form.
Use rags or something else that can soak up the fuel as it drips out. When all you see is a clean fuel with no bubbles, tighten the screw back down while you keep pumping.
This will keep the pressure up and stop air from getting back into the system.
Step 5: Bleed Out Any Extra Points
If there is a second fuel filter, repeat this process with it. That might be all you need to get your engine going again.
If the airlock keeps happening, you will also need to follow the same steps to bleed the injector pump and each injector.
Your owner’s manual will have more information about the parts of your motor.
Step 6: Repeat the steps for pumping
This time take the screw out of the fuel line on the injector pump. Loosen the screw by half a turn, then tighten it when the fuel stops bubbling and stops coming out.
Most of the time, the distance from the fuel-lift pump to the injector pump is short, so it usually only takes a couple of pumps.
Since the fuel is on the pressure side of the fuel pump, it will come out with more force.
Step 7: Ensure there are no complications
Put the engine control in “No-Fuel” mode. Start the engine by pressing the starter button. Examine the fuel leak caused by the loosened fuel bolt.
Allow all of the air to be forced out, then tighten the fuel bolt completely with a wrench once the fuel is clear of air bubbles.
Using shop or Oilsorb rags, clean up any spilled fuel. If necessary, replace the valve cover. Start and run the engine as a test.
FAQs about Bleeding Diesel Engine
What Is The Proper Way To Bleed A Diesel Fuel Line?
The most beneficial method for a bled fuel system is to turn on the ignition without starting the engine. As a pilot, you will only have 30 seconds to work.
This will allow you to use the pump. Restart the engine 15 seconds after turning it off. To resolve this issue, repeat the same task two times until the problem ceases to exist.
How Do You Bleed A Diesel Engine After Changing The Fuel Filter?
In some diesel engines, bleeding the fuel pump can take just one turn of the ignition key, a turn-off, and then four turns until it happens.
The manufacturer, who should be able to advise you, can recommend restarting the engine after a few minutes.
Is It Necessary To Bleed A Diesel Fuel System?
Air bubbles in a diesel block’s fuel line prevent it from fully flowing fuel. To successfully restart your engine, you must first fill it with fuel.
Why Is It Necessary To Bleed Diesel Engines?
The main goal is to force diesel all the way through the fuel system, pushing trapped air out and allowing the engine to start.
Most engines must be bled in a specific order of components, usually secondary filter, injector pump, and injectors.
Why Does A Diesel Engine Bleed Air?
Air is trapped when you change a diesel fuel filter, run out of fuel, or disturb the fuel system. When you try to start the engine, this air acts as a lock, preventing normal fuel supply to the cylinder.
When Should The Bleed Plugs On A Diesel Engine Be Closed?
After all, the air has been removed from the fuel tank, filters, settlement bulb, and fuel pump, close the bleed plugs. Start the engine; if it won’t start or runs poorly, the injection system may need to be bled.
We hope you are satisfied with the answer, “ Where is the bleed screw on the diesel engine” To get rid of the accumulated air, you must know the position and strategy of loosening the bleed screw.
Follow the process we have described to bleed your diesel engine. Also, maintain the precautions of your user’s manual for executing a safe process.