Changing front brake pads open bleeder nipple or leave it closed

[manofthewoods]

I have a mobile mechanic business as a side hustle and, by far, the most work I do is brake jobs. I use a Mityvac to suck out the fluid while I use a ratcheting piston compressor to push the pistons back in. I do this because the fluid in the caliper is exposed to the most heat cycles and its the best way/time to remove the worst fluid. The fluid in the reservoir always looks a lot cleaner than what I pull out of the caliper with the Mityvac. On vehicles that have had a prior brake job, you can absolutely tell if the fluid was removed or not because the fluid will be like black coffee. That being said, in the past, I have simply compressed the pistons and not worried about sucking it out and never damaged the components. I started doing it like this after studying for and passing the ASE brake repair test. It is a little bit extra work but is the right way to do it and will extend the caliper's life in the future.

I'm the black sheep, I guess.
I always open the bleeders on the caliper. Put a hose on it, push the pistons until they are flush. Like mentioned above, i figure this is the worst fluid in the system. I want it gone.

Because the bleeder is open, piston compression is easy/quick. Tighten the bleeder, proceed as normal.

I'll wait behind the MUD woodshed for my obligatory beating

 

[NeilC]

You absolutely can open it and gravity bleed with a clear silicon hose on the bleeder screw. Just make sure you close the bleeder screw prior to a bubble going up the hose into the caliper. I work alone so I use the Mityvac for speed in removing the fluid to the point it comes out clear. I call that a brake fluid flush and include it as part of the brake job. Most shops will charge $99 extra for a flush. I also always replace the rotors because a Power Stop or Dynamic friction 4 wheel pad and rotor kit usually is less than what shops are charging for pads. With most of the shops, the customers can expect to get a call that they will need new rotors which puts them way over my price but at that point it is too late. I charge 20%-25% margin on parts and $100/hr for labor so for 4runners I come in at about $750 w/tax and $850 for tundras. I make between $300 to $400 labor/profit for each job and usually spend 3 to 4 hours on each job. I spend most of my time wire brushing things and cleaning up the hub surfaces. This will be my retirement gig after I retire in 5 months.