How to Flush Micro Sprint Brake Fluid
Over the years, I have tried numerous ways to get rid of existing brake fluid from the brake system in my micro sprint. Yes, it sounds easy, but there are a few different ways to go about it. I am going to go over how I do it and the reason why I do it this way.
Each winter, I try to go through my whole car, take off every piece, and make it a bare frame. I also try my best to flush out all of the fluids: from the water system, oil in the motor, fuel in the fuel system, and even the brake fluid in my brake system. That way, when I start the new season everything is fresh and new. This helps keep the car running at top performance and ensures the system is running as smoothly as it should. Plus, why do you want to race on fluids that you ran all year and then let it sit over the winter? Who knows what type of objects got into the system during those cold winter months.
One of the most important tools in my racecar is my brakes. I use a good amount of brakes while I’m racing. So, I need to keep my brake fluid fresh and make sure I always get old brake fluids out of the car. If you've ever felt like the brake pedal went soft on you, that means the brake fluid started to boil during the race. That is when it is essential to get old fluid out of the system.
The way I flush out the system is a relatively clean and straightforward way of going about it. I have two different types of calipers in my car, so I go about each of them differently. First, I undo the rear brake line that goes to the rear caliper while I still have the front brake line connected to the front caliper. I do this so the brake fluid only has one way to go during the flushing process, kind of a way to force it out.
While I have the rear brake line undone, I place a bucket under the brake line for the draining fluid. I like to zip-tie the line to the frame so I know it is not going anywhere. I then take my hand and start pumping the brakes. I don’t push the pedal fast at all; I make sure I push the pedal down as far as it can go, making sure it is a full pump and as much fluid comes out as possible. I also make sure I give the pedal a good amount of force when I push the pedal all the way down.
It may take some time to get all of the fluid out of the system, just depending on how big the brake system is. I know it took me a good 10 minutes of pumping to get most of the fluid out the system. During the process, I would look at the brake fluid reservoir and watch the fluid level go down. When it all leaves the reservoir, I give the brake pedal a few strong pumps to make sure I get most of it out. Once the majority of the fluid is out, I go to the front caliper and take off the brake line. I place that bucket under the brake line and give a few strong pumps. At this time, there shouldn’t be a lot left, just whatever didn’t make it to the back.
At this point, there shouldn't be anything else coming out of the line. To ensure all the fluid is out, I take the lines out of the car and use my air hose to blow through the line. I do the same thing with the brake reservoir. I don’t blow any air through the master cylinder because I don’t want to damage anything internally. I trust that the brake pumping did a well enough job to get everything out. This process seems like the easiest way for me to do since I am a one-man-band. It is also the cleanest way to do it. I hope this helps your process, and you continue to find it easier than other ways.