A bit of instruction for you folks with an early Evo (and also 1G / 2G DSM). There aren’t too many guides on how to bleed / change the brake fluid on these cars alone and while the procedures are pretty similar between cars, a specific guide is helpful too. I will write a two-person version in the near future, but the one-person procedure is very simple to follow. I don’t want to be patronizing in this guide, but I will try to explain everything as simply as possible. I want this guide to be as user-friendly as possible.
Your brake system is a closed system, but it can sometimes have air bubbles, and when braking hard, the brake fluid can boil, making it much less effective. I would recommend bleeding or flushing the entire system every 6 to 12 months. I will give instructions on how to purge the system and then give additional information on how to purge the system at the end. Brake fluid is also hydroscopic, which means it loves water and absorbs it, making it much less effective. For this reason, when you put new brake fluid into the system, it is much better to use fluid directly from an unopened container. Also, it is best not to do this procedure when it is raining or wet.
Well, to business. First of all are the things you need for this and luckily you don’t need any specialized tools. But you will need the following:
Wheel bracket (my wheel nuts are 21mm, but yours may be different. You most likely already have them)
Jacob
10mm wrench
60 cm rubber tube, 5 mm inside diameter and preferably transparent
Small container (an old jar or something will do)
Brake fluid, DOT 4 or DOT 5.1 if you spend a lot
With all those things ready, let’s get started.
- Go to the rear wheel on the passenger side and loosen the lug nuts a bit. However, do not remove the lug nuts at this stage.
- Pick up the car and take the wheel off.
- Just behind the brake caliper you should see a small metal nipple sticking out. That’s your brake bleed nipple. It could have a plastic cap (both of my front nipples did). If that’s the case, take it out and place one end of the hose over it.
- Fill your small container about 1/4 full of brake fluid and insert the other end of the rubber hose into it.
- Take your wrench and unscrew the 10mm nut around the bleed nipple. A full turn counterclockwise should do it.
- Now go to the engine compartment and open the lid of the brake fluid reservoir. Make sure the reservoir is full of brake fluid.
- Get inside the car and step on the brake pedal slowly and firmly. About 5-8 pumps should be enough.
- Go back to the rear wheel on the passenger side and look at the hose. You are looking for air bubbles, or hopefully the lack of them. If you don’t see air bubbles, congratulations! You can retighten the bleeder nut, remove the rubber hose, and move on. If there are bubbles, check that there is still brake fluid in the reservoir and pump the brakes again a few times. Keep doing this until there are no more air bubbles. Make sure the brake fluid reservoir does not drain; if it does, then air will begin to enter the system.
- Replace the wheel, hand-tighten the wheel nuts, and lower the car. Tighten the wheel nuts with the clamp and continue. If your brake fluid bottle begins to fill when you have finished a wheel, drain it to 1/4 full according to your country’s rules for disposing of brake fluid.
And that’s it! The next wheel to lift is the front of the driver’s side, followed by the rear of the driver’s side, and finally the front of the passenger’s side. When you’ve done all four, make sure the brake fluid reservoir is filled to the max level on the side and the top is screwed on tight.
So that’s the procedure for bleeding the brakes. To clean the system, it is an almost identical procedure. Simply bleed a full reservoir of fluid through the system for each brake. Again, make sure the reservoir is never completely empty. To do this, you will probably need 1-1.5 liters of brake fluid.
I think it covers it all. If this has helped you or you have any questions please let me know. I will try to write more of these guides if people tell me what they want to read.