How To Bleed Calipers with Two Bleeders


brake calipers

It’s easy to assume that there’s no way to bleed brake calipers with two bleeders. That is until you realize that it can be done. The problem is that the process is not as straightforward as one might think. How can you bleed brake calipers with two bleeders?

To bleed brake calipers with two bleeders, you need to bleed the front calipers first, then the rear. The rear calipers have a reservoir that holds a certain amount of fluid. Once this reservoir is empty, you can’t add any more fluid. So, if you want to bleed both front and rear brakes with two bleeders, you need to first bleed the front calipers. 

The first time you see a caliper with two bleeders can be confusing, as most calipers we are used to have only one. Why are there brake calipers with two bleeders? How can you make bleeding your calipers easier? Let’s dive into these topics.

Why Do Some Brake Calipers Have Two Bleeders?

Before we can begin with instructions on how to bleed brake calipers, you may be wondering why some brake calipers have two bleeders.

Some vehicles have different-sized brake calipers. In the case of rear brakes, this means that a caliper may have two bleeders. This is done because the two bleeders are spaced differently on the two different-sized calipers

For example, one caliper may have a larger bore than the other, so bleeding both of them is necessary.

How Do I Bleed Brake Calipers With Two Bleeders?

Bleeding brake calipers with two bleeders isn’t much different from doing it with one bleeder.

Follow these steps:

  1. Drain the system of all fluid. 
  2. Open the bleeder valves on both calipers
  3. Bleed off some of the fluid that’s in there. 

This will tell you how much to bleed with two bleeders and help determine if your brakes are working correctly or could use service.

How Do I Know How Much To Bleed With Two Bleeders?

Here’s how to tell how much you need to bleed your brake calipers with two bleeders:

  1. You can use an old brake fluid gauge to determine how much to bleed with two bleeders 
  2. Put the end of your old brake fluid gauge into one of your brake lines
  3. Check how much fluid comes out
  4. The amount should be around half of what you put into the line.
  5. If you don’t have an old brake fluid gauge, you can use your old one to check the amount

Now, let’s take a look at how long you should bleed your brake calipers with two bleeders.

Can Bleeding Brake Calipers for Too Long Cause Issues?

Brake systems need to be properly bled throughout the life of the vehicle because a little bit at a time keeps them running smoothly without any issues.

However, bleeding your brake calipers for too long can cause problems within the braking system itself, such as:

  1. Reduced stopping power
  2. Increased noise levels
  3. ABS sensors trying to compensate by slamming down harder than they should mechanically
  4. Rotor damage
  5. Overheating rotors due to excess friction caused by air bubbles being trapped inside
  6. Sensor failure
  7. Uneven wear/shifting between rotors
  8. Catastrophic failure of the brake system

Now, let’s look at the next section.

Should I Use a Vacuum Bleeder with Two Bleeders?

Now that you know how to bleed your brakes and that you shouldn’t bleed them for too long, you may be wondering if you should use a vacuum bleeder for this process.

It’s unnecessary to use a vacuum bleeder when bleeding brake calipers with two bleeders. Simply put, a vacuum bleeder is designed for vehicles with larger bore lines than those used on most vehicles today. 

The next time you’re in your local auto parts store, pick up an old brake fluid gauge and see how much fluid comes out of it. You’ll notice that the amount of fluid is only a small drop compared to the amount of fluid that comes out when you use two bleeders.

3 Tips for Bleeding Brake Calipers with Two Bleeders

Bleeding a caliper with two bleeders is not as simple as it may seem. You can easily end up with one or both of the bleeders out of sync, which could result in you bleeding the brakes again. 

So, here are the three tips to help you get the job done right:

  • Use a clean hose and make sure all the parts of your caliper are clean and dry before using it. Oil will cause corrosion and rust, so make sure all oil is removed from the tool before use.
  • When using a single-bleeder kit, make sure that you have enough length to reach between all of the parts of your caliper. If you’re using an adjustable bleeder tool, ensure that it has enough adjustment to reach between all parts of your calipers.
  • You can use a pair of very small needle-nose pliers to hold one part while you use the other part to bleed them. This will help you get a better grip and also ensure that you don’t end up with one of your bleeders out of sync.

Now you know everything about bleeding calipers with two bleeders.

Clearing Up Double Bleeder Confusion

It can be confusing when dealing with a brake caliper with two bleeders if you haven’t seen them before. It may be hard to remember which bleeder goes where, even if you have. The three tips above will help you get the job done faster and more efficiently.

Arwood

I'm Arwood, but the grandkids call me Big Papa. After retiring from teaching automotive classes for 30+ years I decided to create a blog about all the questions I used to get about brakes and anything automotive.

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