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What Size Are Bleeder Screws? (Quick Answers)

Using a vehicle can come with many pros, but they also come with some of the most anxiety-filled cons. One of them is the hassle that we need to deal with the hydraulic brake pads. 

Upon using the car for around 6 months or more sometimes, we will start to feel that the brakes feel smoother rather than stiff. 

It is around that time the brakes stop functioning properly. This is mainly because of air and moisture or other elements that get trapped in between the brake calipers. 

This hassle of brakes not working properly does not happen overnight, but rather over time when it is not taken care of. 

Therefore, we all need to do some maintenance work for the vehicle we have every 6 months (recommended). However, if we happen to do things on our own, we would need to know what size of bleeder screw we need. To know more about that keep reading below. 

What size are bleeder screws? 

There is not one definite size of bleeder screws. There are different sizes of bleeder screws. Standard and metric brake bleeder screw size can be ¼”-28x. 92”. The usual bleeder screw size can be 10mm. It can also range between 8mm/5/16″. Since there are so many designs, it cannot be helped.  

There is not a universal size for the bleeder screws for vehicles. That is why we need to understand the differences between most of them. Down below is the list of manufacturers of braking systems and different car companies that use different sizes of bleeder screws. 

Silverado bleeder:

The Silverado is one of the best sellers in the market of pickup trucks in the whole United States. This vehicle requires bleeder screws of M10-1.5 X 30mm size.   

Wilwood bleeder:

Wilwood Brakes are one of the biggest manufacturers of braking systems for vehicles around the globe. The brakes of this manufacturer use 220-0627 brake bleeder screws that go along with the Wilwood Calipers. 

That is 1/8 Inch-27 thread size.   

Brembo bleeder:

Brembo is one of the most renowned innovators in the case of the braking system of vehicles. They make high-performance braking calipers for all tiers of cars, and those brake calipers use the 16mm bleeder screw size.   

Duramax bleeder:

A joint venture between the mega companies known as Isuzu and General Motors came together in Ohio to make this beast of a vehicle called Duramax. The brake caliper on this vehicle has a 1/8-27 NPT bleeder screw size. 

Harley bleeder:

We do not have to explain much more about this company, they are widely known throughout the world. Harley bleeder screw size is 44146-77 3/8”-24 thread.   

Toyota bleeder:

Toyota is also a car manufacturer that is famous among the Asian countries the most. Moreover, their auto-grade brake bleeder screw size is M10-1.0 X 35mm

Polaris bleeder:

These cars are the most luxurious and unorthodox when it comes to designs. They usually design specialized vehicles for the military. The bleeder screw size of those cars can be ¼-28 of standard machine size. 

What size wrench is the brake bleeder screw? 

When it comes to tools for particular things, we always have that one constant size for almost everything. That size can be the standard size that was issued by the regulations of that current region. Therefore, sometimes the sizes can be different for different things. 

In this case, brake bleeding is the process in which the hydraulic brake system where the brake lines are purged of air bubbles. The size of the screw can be different, but the size of the wrench can be constant. 

Therefore, the correct size of the wrench that we need for the brake bleeder screw is 5/16 in. X 3/8 in. This one is particularly constructed in durable material and will fit perfectly to save you from a headache. 

Are all bleeder screws the same size? 

Bleeder screw is the screw that can create an opening that is temporary in the hydraulic system that is usually closed. Brake bleeding is the process that is done to remove the air bubbles in the hydraulic brakes of a particular vehicle. 

The removal of air bubbles is not the only thing that one does when brake bleeding. Other elements need to be removed from the system and they use the pressure and density difference to figure that out. 

Furthermore, the headache part of this process is that not all bleeder screws are the same size. That is why there can be aftermarket screw kits found on the net for purchase to make this process less of a hassle. 

These can range from cheap ones to premium ones that have other tools included in them. 

What thread are brake bleeder screws? 

When we go down the rabbit hole of DIY everything. We find ourselves in a place where we need to buy different kinds of tools for the sole purpose of figuring out the problems in our machinery or vehicles and solving them as well. 

Sometimes the process can get an overwhelming number of different tools and sizes to think about. When we got the perfect size of wrench for the job of brake bleeding, we would need to also have a particular size of bleeder screw that will be compatible with it.  

In this case, as a standard size, the screw can be M8 x 1.0 Thread Sz, PK5. The dimensions of the product is 3 x 1.2 x 0.7 inches. The fastener size of the product is M8 and its weight is 1 pound. 

What kind of bleeder screws to use? 

Brake bleeding is a process where the brake fluid goes through a mechanism to release some of the fluid. This process allows us to get rid of the bubbles that are inside the brake pads inside the brake calipers.  

The process might seem daunting, but it is a necessary step that requires us to utilize the brakes more efficiently. When there are other materials and air bubbles in between the brake calipers, if we push down on the brakes, the calipers will not work properly. 

Therefore, bleeding the brakes helps with the aforementioned issues. Normally we need to use 10mm size of bleeder screws, otherwise, the size can range from 8mm/5/16″ too. The size is different due to different brake calipers more or less using different sizes of it. 

How long are bleeder screws? 

When bleeding the brakes of your vehicle, we need to make sure the process is followed by the proper selection of tools and materials needed. Sometimes, we will find ourselves in the situation of non-compatible bleeder screws when replacing them. 

This is more prevalent in older cars but these days the standard bleeder screw size can be 10mm. The size may range in different other sizes due to the manufacturer of different cars. However, the size remains closely similar to this. 

Furthermore, in the case of the bleeder screw, all it needs to do is bottom out the conical head to stop any fluid from coming out. Therefore, if there are slightly longer or shorter threads, then that should not make much of a difference. Usually, they can be around 3 inches long

How to size bleeder screws properly? 

The process of bleeding brakes can be tricky due to not having the right tools, here is a step-by-step guide on how to properly know the bleeder screw size and bleed the brakes. 

Figure out how much we push on the brake: 

We first need to figure out how much we push on the brake that we start to feel if there is any paddle engagement. This makes us clear how much a brake pedal is working properly. 

When the brake goes halfway or more after pushing then we can understand that the brake pads are not working properly. 

Bleed the brake caliper: 

In order to make the brake pads work properly. We would need to bleed the brake caliper of its brake fluids. To do that we will need a bleeder screw. Usually, we would not need to change the already installed bleeder screw to get the job done. 

Measuring the size of the bleeder screw: 

When it comes to measuring the size of the bleeder screw, we do not need to look beyond the already installed one in the brake calipers. If that particular one is not available then that is also fine because they are easily available. 

The general size of the bleeder screw can be 13mm for nipple and nut, then the thread is 7mm and the body is 10mm in size respectively. We get the proper wrench and install the new bleeder screw to clean out the air bubbles inside the brake calipers. 

Final Thoughts 

The bleeder screws of a particular vehicle can differ from manufacturer to manufacture. There is a standard size for the screws in general but sometimes they will not match. However, that certain measurement is around 10mm. The size can range from between 8mm/5/16″ in other car models.