Flushing the Brake and Clutch Fluid
Brake fluid is one of the essential fluids in your car that needs to be changed at regular intervals. The service-recommended interval is every two years, but it should be done annually if you drive your car aggressively and especially if you do any track days. Brake fluid is prone to contamination from both age and hard use. If pushed too far, it can actually lose its ability to maintain pressure in your braking system.
What that means in plain English: If your brake fluid goes bad, your brakes won't work.
The picture below shows what contaminated brake fluid looks like. The fluid will look dark when first drained from the caliper. I let this sample sit for a day and the contaminants ended up separating from the fluid quite a bit, so you can see just how much contamination is in the fluid.
And this is what fresh brake fluid looks like. See how clean and clear it looks!
DISCLAIMER: As always, follow all safety protocols. Don't undertake this task if you aren't comfortable with it and fully understand it. You are ultimately responsible for anything you do. Neither Redpants, LLC or myself is responsible or liable for anything that may occur.
CAUTION!! Do NOT drain the clutch line if you have a SportShift transmission! If the clutch line is drained, there's no way to get fluid back into it without an AMDS. Your transmission will not shift, and your car will need to be shipped to a dealership to have them fix it.
This DIY is still under construction!
1-1.5L (2-3 bottles) of brake fluid (I recommend Motul DOT 5.1 or RBF600)
Pressure bleeding system (or a second person)
11mm box-end wrench
14mm box-end wrench
Drain pan or container
Shop towels or paper towels
Brakleen or other brake cleaner
About an hour
Do NOT let the fluid in the reservoir get too low! If air gets into the system, you'll have to bleed it until all of the air is gone, costing you a lot of fluid in the process.
Doing this job solo is very easy if you have a pressure bleeder system. The one I use in this DIY is the Motive MVP-0250, which costs about a hundred bucks and can be easily found at online retailers. If you don't have a pressure bleeder, you'll need a second person to pump the pedals. This DIY is written using a pressure bleeder, so if you're using a second person instead, have the person pump the brakes in lieu of pressurizing the bleeder when called for.
The amount of brake fluid needed for this job depends on how thorough you want to be. A single bottle can refresh the system, but to do the clutch line will require extra, and you'll need even more if you want to do a comprehensive flush. For the cost of the fluid, I highly recommend getting three or even four bottles (1.5-2L total). The fluid isn't so expensive that you'll need to worry, especially given the savings you're still getting by doing this job yourself compared to paying a dealership.
The manner in which I use the pressure bleeder is different than the norm. This method was suggested by one of the forum guys and it's a great way to greatly reduce mess and cleanup. Instead of filling the bleeder with fluid and pumping the fluid into the reservoir, this method uses the bleeder to pump air into the reservoir. Fresh fluid is added directly to the reservoir and then pushed into the sytem. It does, however, take more time because the bleeder has to be removed for the reservoir to be filled up several times rather than filling the bleeder with fluid one time.
Get the car up on jack stands, or use a lift. Alternatively, you can just lift one corner at a time. For safety and simplicity, I suggest getting the whole car off the ground at the same time. It'll make the whole job go quicker.
Remove the cap from the brake fluid reservoir.
Attach the pressure bleeder to the reservoir. Pressurize the bleeder and check for air leaks.
Locate the bleed nipple and remove its cap. Attach the drain hose to the nipple and get your drain pan or container set up to catch the fluid from the drain hose.
Pressurize the bleeder to 15 psi.
Use the 11mm box-end wrench to open loosen the bleed nipple. You'll see brake fluid coming out of the nipple and into the hose. Do NOT remove the nipple! You only need to loosen it so fluid can come out. You should see the fluid color change as the fresh fluid gets through the line and pushes out all the old fluid. The fresh fluid will be lighter than the old fluid.
When fresh fluid starts to come out, tighten the bleed nipple to close it. Remove the drain tube, use the brake cleaner and towels to clean the nipple, and put the nipple cap back in place.
Refill the reservoir and repeat Step 3 for each of the bleed nipples. There are two per caliper, so eight total.