So a friend and I changed the pads on my WRX (successfully) and tried to bleed the brakes. The result: 6-inches of spongy pedal travel.
I’ve been trying to figure out what I did wrong. I found two mistakes that probably caused the problem. Let me know if my diagnosis sounds correct because I want to be able to do it properly in the future.
First Mistake: we bled them in the wrong order. We worked from front right and worked counterclockwise. Granted, we only bled the brakes rather than completely flush the system, but it still isn’t the correct way to do it. I don’t think this was the main problem considering my friend has never had an issue bleeding his brakes out of order. I think the second mistake was the real culprit:
Second Mistake: we let air get into the brake lines. We loosened the bolt to let the brake fluid drip out, slowly pressed/released the brake pedal twice, and then tightened the bolt again once it stopped dripping.
In hindsight, we should have started pressing the brake pedal first, and then loosen the bolt. Let the fluid drain, and tighten the bolt again before releasing the brake. By keeping the bolt open the whole time, we probably just sucked air into the brake lines every time we released the brake pedal.
Btw, my friend has always used a pressurized brake bleeder for his Ram, Cayman, and Z06, and has never bled brakes without using one. Now that I think about it, the technique we used on my WRX probably would be acceptable if we had used a pressurized brake bleeder, since it prevents air from getting sucked into the brake lines.
And since I commute into NYC on weekdays, I had to drop the car at a garage so they can fix it (and borrow my dad’s Tundra in the meantime). Not a great start for someone who has never wrenched before and is now extremely hesitant to ever try it again.