Bleeding Brakes

[lmholmes11]

Hello all, I have just done all new pads, rotors and calipers on my 2001 D/A. I know you have a helper push down on the brake pedal until its hard and you bleed the brakes rear right, rear left, front right, then front left, but ill be danged if I can get the brake pedal to be firm the first time before I crack the bleeder. Is there something I'm missing? There is enough brake fluid in the resevior, and no leaks. Thanks guys

[bobt]

My experience is that it isn't necessarily firm the first few pedal pushes until you get most of the air out of the system.
Bob

[DmaxMaverick]

That's normal. The pedal shouldn't be firm until all the air is out and all the caliper slack is taken up (pads fully engaged and caliper adjusted). Don't kill yourself pumping the pedal at first. Once the pedal is the same twice, bleed. Any more is a waste of effort, and continuous hard pumping can cause air in the system to travel up, where you don't want it, and make the bleeding take longer and use more fluid. DO NOT allow the fluid level to get low enough to allow air in. Bleeding the ABS module can be a real PITA!

Tips and tricks:

"Suck" out as much old fluid from the reservoir as you can, and fill with fresh fluid. This will lessen the time/cycles getting the old fluid out. No need to push all that old stuff through the system.

If starting with a new fluid bottle, do not remove the seal. Punch a hole in it about the size of a pencil. Invert the bottle onto the reservoir fill. This will keep it full while you bleed (until the bottle is empty. like a water cooler). This will save a bunch of trips to under the hood. Check the level about 5-6 bleed cycles. Once the bottle is empty (and you have more bleeding to do), replace the empty bottle with a fresh one, the same way. If done correctly, it's a no-mess process (under the hood, anyway). If the seals are already removed from the bottle(s), you can still do this. You just have to be a bit more coordinated to minimize spills. Secure the bottle in place with tape or something so it doesn't topple over if using larger bottles (larger than 12 oz.).

Use only a box-end or a tubing wrench (better yet), on the bleeders. Using anything else can cause the hex flats to round off. You can use a 6 point socket to loosen them at first, and to tighten when finished. It's always a good practice to replace the bleeders when doing a brake job, if that's an option. New calipers should have new bleeders. Reman's may not. Any sign of corrosion will come back to haunt you the next time. Once the job is completely done, seal the bleeders (and where the bleeder meets the threads) with a thin coat of RTV if you drive in the "salt belt". This will ensure easy loosening in the future. A bit of brake cleaner to remove any fluid/oil helps the RTV seal against the metal.

When bleeding, use minimal pedal pressure while the bleeder is open (light, constant pressure throughout the stroke, and don't lift until the bleeder is closed). More pedal pressure is smaller air bubbles (higher pressure), which may not exit as easily.

A thorough flush will use a couple quarts, or more. Make sure you have enough before you start. Bleed/flush into a clear container or use clear tubing on the bleeder. You'll be able to see when you have pure/fresh fluid bleeding. The old fluid will have water, acids and debris particles in it you want to get out, so be thorough.

[lmholmes11]

Thanks guys, do I need to have the ignition on? (Not started just accessories on?)

[DmaxMaverick]

No ignition.

[lmholmes11]

Thanks guys, I got er done easy enough. Thanks