I am wondering if there is a pattern that should be followed in bleeding my brakes? I'm putting new pads on, and want to know if there is a certain wheel that should go 1st, 2nd, 3rd, and 4th. On my WRX, everyone recommends a pattern based on how the master cylinder distributes brake fluid to the 4 wheels.

 

start farthest from the brake booster.

so..
rear passenger
rear drivers
front passenger
front driver

 

If you are just putting pads on and you do not allow air in the lines, there is no need to bleed them.

 

thats true bluejay, but i was simply answering the man's question.
-Patrick

 

True, however, being that brake fluid is hygroscopic, it will pick up moisture from the air it's exposed to, and you will lose pedal feel. It's recommended that the brakes be bled at least every 2 years to maximize the life of the system. You'd be amazed at what a difference in brake feel it makes with fresh fluid in the system.

-Joe

 

I'm guessing I will, because in order to get the piston to reseat itself, I'm gonna have to disconnect the brake line to release the pressure. Meaning, the brake pads are worn down so much, the new pads aren't going to fit over the rotor with the piston in the same position.

 

Use a C-clamp. Put an old pad against the piston and use a clamp to press the piston in. Don't undo the line. You would still have to clamp the piston even if you pulled the line.

 

Indeed. With no pressure on the brake pedal, there will be no pressure in the line. Personally, I prefer to crack the bleeder screw to compress the pistons anyways. It's just that much less fluid I need to bleed through the system once it's all back together. A c-clamp alone will recompress the piston though. It'll just force the fluid back into the master cylinder reservoir.

-Joe

 

Just take the cap off the master cylinder before you compress the calipers. If your pads are worn almost completly down, and the MC is at the high end of fluid, you may need to remove some fluid so as to not over run. A large syringe, or even a turkey baster, will work to suck out some excess fluid.

When the job is complete, fill the MC back to the correct level.

In the thirty years I've been replacing brake pads, or the million plus miles I've put on my vehicles, I've never bled the lines. Or had rotors turned. But hey, I've never let pads get completely worn down, either. That's just my experience on the matter.

 

I wanted to say thanks for the C-clamp idea, that worked great. With the help of my brother it took just a bit more than 1 hour. Changing the pads on the truck was so much easier than my WRX. You don't have to take everything apart and the pads just popped right out and in. However, I forgot about the fluid being pushed up into the resevoir after pushing the pistons back, and had a couple of puddles of fluid on the ground. It wasn't that bad though. Thanks again.

 

I think the lines should be bled every few years. But I haven't even though I put 200K on most. In 48 driving years of driving I've never had a leak or problem because of it. Shame on me

 

Not only bleed the lines every few years (or at least when you change pads) but completely change the fluid. Flush out every bit of the old and replace with new. I use a turkey baster and get as much out of the reservior as I can, then re-fill with fresh. Then start in the pattern Patman said and bleed them until the fluid runs clean. That first wheel (right rear) seems like it takes for ever to get clean fluid back there but man is it worth the trouble. Bang-for-the-buck, this is probably hands down the best thing you can do for your brakes...Just don't suck the reservoir dry while you're doing this. Keep it full.

 

I agree 100% with Galaxy, Flushing the old fluid out is the best thing to do, I do it on my vehicles when I change the pads. Heck, It is easy to do and only cost 5 bucks for a quart of Brake Fluid. I don't like that old dirty fluid in there, it makes me feel good to see that nice clean brake fluid coming out the bleeder.
Also, I wanted to point out that clamping the calipher piston and pushing the dirty fluid back up into the ABS or Master Clyinder is NOT a good idea. It's always best to open the bleeder screw and then compress the piston back into the caliper, so the dirty fluid comes out, close the bleeder screw, put on the new pads, then add clean fluid to the Master Cylinder. Hey, what's the big deal, Brake Fluid is cheap!