Bleeding power brake system

Some simple questions, but I've never bled a power brake system.

Can you gravity bleed system with a booster same as manual brakes?

If doing the pump brakes, hold, bleed and repeat method, does the car need to be running?

Thx

I've never had much luck with gravity bleeding in general, but have bled power brake systems with and without the engine running. Procedure is as you described.

I've have good success using a hand held vacuum pump bleeder as well, since often I'm by myself. The Harbor Freight one works well for my needs.

Exactly how does the HF tool work? I have a bit of a soft brake pedal and wanted to bleed the brakes to see if that does anything. I usually only have my 12 year old to help if I need a second set of hands. I was reading the manual online for it and one section says fill the brake fluid and bleed. Later on it says to fill the brake fluid and replace the master cylinder lid.
Is this idiot proof?
What order would you go in? I'm thinking right rear, left rear, right front, and then left front but not positive.
Details of each step would be appreciated.

Its the same power or non.I gravity bleed then always try reg bleeding.Gravity almost always works though.Just reg bleed to make sure no air in lines.The booster does nothing more than give the pedal mre power on activation.has nothing to do with the hydralic system.Rocky

I have one of the mighty vac systems and it works great for power or non power, makes it a one man job.

My boys got pretty sick of pumping the pedal for me while growing up. My wife always got confused between pump the pedal and hold the pedal, so that didn't work too well.

The Harbor Freight pump, like all others I've seen, just consists of a hand activated plunger type pump with a small vacuum gauge, a small reservoir and rubber hose coming out one end.

You slide the rubber hose over the bleeder screw, crack the bleeder and then just hand pump the unit. It will create a small vacuum and draw fluid out of the system, catching the fluid in the reservoir. By watching the fluid coming out you can pretty quickly determine if you're still getting air, or solid brake fluid through that when cylinder.

Then close the bleeder, remove the rubber hose, make sure that bleeder is closed tight and move on to the next one. (remember to check master cylinder fluid level because you're drawing brake fluid out of the system).

You're correct on the order of wheels to follow. You don't necessarily have to put the lid back on if using the vacuum pump. Just make sure no junk can fall into the master cylinder while working.

You typically would want to put the lid back on when using the pedal because sometimes the pedal action will cause brake fluid to splash out of the master cylinder. Brake fluid can do a number on painted surfaces.

In any case, just be sure you keep checking the fluid level so you don't run the master cylinder out of fluid and end up having to start over again. If you keep the bleeder reservoir clean you can just pour that fluid back into the master cylinder.

Since I can do this, I would have to say it's pretty much idiot proof. Just make sure you've a good solid pedal before going out for a test drive.

Good to sit static with pressure on the brake pedal for a while to make sure the pedal stays in position and doesn't slowly go toward the floor, which would indicate something is leaking or the master cylinder is bypassing internally. On rare occasions I've had a bleeder screw I had to retighten to get it sealed up completely.

Hope this helps.

be sure & bleed the MC first, then the corners & if you use the pedal (eng running) put a block of wood under the pedal so the cup seals stay in their normal wear area (not a dealbreaker but everything helps) & it lets your helper easily get/hold the pedal to its "stopped" position so as to not pull air back in if they would raise the pedal.

Thx for the responses, I think I have the HF bleeder, but could never figure out how to use it.
I'll try and find it and give this thing a go.......

I've had success 3 ways.
1. gravity bleed & just be really, really patient
2. Regular open bleeder, push down pedal & hold, close bleeder & repeat.
3. Hand held vacuum pump & you suck brake fluid through the bleeder screw instead of pumping it with the pedal as in (2).

Rapid makes a good point to bleed the master cylinder first. To ensure you get the air out of the back brakes, pull out the little pin in the proportioning/hold off valve (can't remember which one has it if the two are separate on your car). You can find it if someone pushed down the brakes for you it will pop out 1/8".

Lots of Youtube videos on how to use the vacuum pump for bleeding brakes. AS mentioned, make sure you have fresh fluid in mc first after it was bled. That should help ya!