How much brake fluid do I need for bike?

You’re already late for your interview! 

At that very moment if your bike’s brake doesn’t work properly that’d be a disaster. Therefore, you should maintain a routine and bleed your brakes accordingly.

But how much mineral oil to bleed shimano brakes? 

You’d need approximately 50ml for bleeding both the front and rear brakes. However, it sometimes depends on whether you’re experienced or not. If you’re a newbie in this process you should buy around 70ml or more. But again it also depends on the brake. Some brakes take less mineral oil than usual.  

This was just a glance at the whole method. The quantity of mineral oil is interrelated to many other things. 

Let’s find out about everything now- 

How Much Mineral You’d Need?

Source: https://epicbleedsolutions.com/

From cleaning rotors without brake cleaner to bleeding Shimano brakes, it all comes down to the right process. 

So, are you thinking of shimano brake bleed procedure? 

If yes, then first let’s know how much mineral oil you’re gonna require for the process. 

If you’re doing front and rear brake bleeding togetherthen you’d need double fluid. In that case, you can grab a 50ml bottle of brake fluid. If you already got a 100ml bottle then good news! You can bleed your brakes around 2-3 times more.

Shimano slx brakes don’t even need the whole 50ml for a full shift of fluid.

But there’s another thing you should consider while calculating the quantity. That is if you’re an expert in this process or you’re just a beginner. 

When I first started I spent more than it required. I had just spilled almost 15ml only attempting to refill the puddle. But with time I sometimes don’t even need the entire 50ml.

Also, if you haven’t bled your brakes for more than a year then I would suggest doing it now. Start with washing out all the previous mineral oil. So in this case, you’ll require at least 100ml brake fluid.

Another important calculation is how much mineral is left in there. If you have 15ml oil left in your brake system, you’d need to bleed around 100ml of mineral oil. 

Brake bleed kit

There are plenty of brake bleed kits out there. These kits actually ease the whole bleeding process. With these kits, you’d not even need to worry about your mineral fluid quantity. 

For example, I’ve always noticed one Shimano rebleeding kit does the job easily. This kit comes with all the necessary equipment. Such as a bleed block, close and caliper adapter, bleed bottle, syringe, gloves. 

And most importantly, it includes a 60ml mineral bottle. It’s more than what you’d normally require because most of the time spills happen. 

However, this particular kit isn’t compatible with Shimano hydraulic brakes. So when I bleed hydraulic brakes I use either one of the two mentioned below-

Now there’s one more thing that can be a good lesson for you about quantity. Let’s find out what it is-

What’s the Catch?

Well, there’s just one catch and this is quite small but very important. While bleeding you might find it difficult to nudge the caliper pistons back. The reason behind this is recently overfilled fluid. 

So, to nudge back the caliper pistons it’ll need more space to adjust those sleek brake pads.

Long story short, if you’re overfilling your brake then it’ll get difficult for you to readjust the pistons.

However, thankfully the fix is easy. You can push back the pistons by simply removing the lever bleed port screw. Next, the pistons will shove back the additional mineral on their own. 

So now you’ve got your required mineral fluid to bleed the brakes. But do you know how to bleed Shimano brakes? If not, let’s have a discussion over it. 

Because if you’re unaware of the accurate method it can take way more than usual fluids. Hence I’ve explained the whole process for everyone. 

Source: https://epicbleedsolutions.com/

Apart from the kit equipment, you might need some more things. They are-

If you’ve got your kit and gathered all the other equipment, let’s start the process-

Step 1: Take the Pads Out

First thing first, pull the pads out. Next, clear the brake pads with a neat cloth. After that place them somewhere stable, in a separate room.

You shouldn’t touch the pads until you’re done with bleeding. And cleaned everything else and yourself as well.

Step 2: Time to Use the Bleed Kit

In this step, inbox your bleeding kit. Then take out 2 syringes. One of them should be a 50ml syringe and the other one a 10ml syringe. 

Then find out the hose as well. The hose should be around 10cm and clear. 

Step 3: Force in the Mineral Fluid

So, the bigger syringe is for pushing the fluid through the caliper. And the little syringe is for removing the additional fluid from the lid paddle. 

The amount of removed fluid is the unclean one. Store it in the zip poly bag to safely dump later. 

You see, the actual satisfaction of Shimano brakes is, you can easily push back the pistons. All you need to do is shove them with the edge of the 7mm spanner. 

At this point, you’ll be required to roll the bleed nipple. Also, you don’t require pads in to shove the pistons back.

If want to visually experience the whole process then watch the following video-

Now, you know how much fluid you’d need to bleed the brakes. Then you got to know about the whole process. But do you know which minerals you can use for bleeding?

Because if you don’t know it might be a problem. As different oil or fluid has different viscosity it can affect the quantity. Moreover, anything denser will make your brakes sluggish on return strokes.

So let’s clear this confusion right now!

Are You Having Confusion About Brake Fluids? 

First, an important tip is never to use mineral oil brake fluid in place of DOT brake fluid. DOT brake fluid is manufactured for other applications. 

So if you don’t maintain the instruction it can result in some major issues. Such as seal damage, internal breakdown, and shocking brakes.   

Because DOT fluid consumes water. That’s why you’ll find it at the same place when you need to bleed again. It won’t wipe away easily. Therefore, you’d need extra mineral fluid to rebleed and replace it.

Hence, always ensure which brake fluid you’ll need for your brakes before buying. Because whether it’s the finest coaster brake-hub or bleed fluid, everything’s useless at the wrong place.

So according to your brake model you can check which fluid is appropriate for you. To clear your confusion you can browse the following table-

Source: https://epicbleedsolutions.com/

You can also easily find out the type of brake fluid you’d need. You’ll just need to check your brake lever. This can normally be found printed there.

Now let’s see how often you should bleed your brakes. According to that, you can order your required brake oil for a specific period. 

How often should I bleed my brakes?

Source: https://epicbleedsolutions.com/

Whenever you feel your brake lever is spongy, it’s time for bleeding the brakes. Because it happens when air finds its way into the brake system.

Don’t keep riding with this situation in hand. Otherwise, it’ll affect your brakes in no time and you’ll face many issues. That’s why prepare a routine and change the brake fluid according to that. 

Riders who compete and require extensively from their brakes should consider shifting their brake fluid yearly. For the rest of us, removing the brake fluid every two years is standard. Therefore, it’ll be easy to retain a high boiling level of the fluid.

FAQ

Why do you find spongy brakes after bleeding? 

You find spongy brakes because there might be the air that got into the brake lines. It normally prevents the brake fluid from appropriately flowing. 

How much do I have to spend to bleed bike brakes?

On average you might need to spend around $30. However, it depends if you’re going to take bike shop service. Otherwise, you can wrap it up within $20 at home.

Summing it Up

Hope now it’s clear to you how much mineral oil to bleed shimano brake.

However, in that case, even more, important is choosing the right mineral. So, keep that in mind for your own safety. 

Ciao!