Brake flush procedure using power bleeder

[John W.]

Brake flush procedure using power bleeder

I have learned a lot from this forum (thanks everyone for the great advise) and would like to give something back. After searching and reading a number of posts, I did a brake flush for the first time and decided to write up a detailed procedure for someone else new at this.

What’s needed - Motive power bleeder (black label one has a nice metal cap and is worth the extra money – some on this site have made their own pressure system – you can search for that), hose for bleeder valve to drain bottle (or get Motive catch bottle kit), 1 liter brake fluid - works well to switch between ATE gold and blue, 9 mm wrench for bleeder valve, jack, jack stand and wheel lug wrench.

You must clamp the vent line. When looking at the reservoir from the front of the car, a vent line is at the top (nearly cap level) and exits to the right (driver side). This must be clamped shut or you’ll have fluid on the floor and no pressure in the system. I tried vise grips with a cloth around the hose to protect it and it still leaked – I then used a small C-clamp which worked great.

Remove the reservoir cap and siphon out most of the old fluid from the reservoir – the wife’s turkey baster works well – be sure to get her a new one or sleep on the couch.

Connect the Motive power bleeder or similar system to the reservoir and pressurize to 10 - 15 psi. to check your connections for holding pressure. If you have a leak - check the cap, hose clamp and all fittings.

When it’s holding pressure - release the pressure at the pump not at the reservoir – you don’t want fluid flying out.

Top off the reservoir with fresh brake fluid and reconnect the Motive.

Break loose the wheel lugs on all four wheels or plan on turning the two front tires to get access to the bleeder valves.

Jack up the right rear, lower onto a jack stand and remove the wheel.

While you have access, check your brake pads minimum thickness is .08”.

Pressurize the Motive system – I didn’t add fluid to the Motive – makes cleanup easy but you MUST check the reservoir frequently and add fluid to it a number of times. I checked it after each wheel. Be sure to always release pressure at the pump not at the reservoir.

Remove dust cap from bleeder valve and connect hose to the valve and put the other end in your catch bottle. Open bleeder valve slightly (mine used a 9mm wrench) and carefully watch until the new fluid starts to come out and no bubbles. Close valve snug but not too tight. Remove hose and replace dust cap. The blue fluid stains the system and it’s a little hard to see when the gold starts coming out.

Replace the wheel and repeat the process moving from right rear to left rear to right front and left front.

Some people suggest going around the car again, I just redid the right rear wheel and ended up with a nice hard pedal.

Be sure to tighten all wheel lug nuts - Torque to 96 ft.lbs. = 130 NM

Be sure to top off the reservoir with brake fluid and replace the cap.

[Joe Bob]

I like using a different color fluid. Easy to know when you've flushed enough.

[tmblackflag]

Bumping an old thread here but I just bought a motive and will be attempting this for the first time next week. Couple questions....

1) If flushing and not just bleeding, wouldn't it be better to just fill up the power bleeder reservoir instead?

2) Since flushing it seems like the reservoir would empty out pretty fast, even starting with just the rear right wheel. Will refilling it after each caliper really be enough?

[James Brown]

the fluid comes from the motive tank through the reservoir which will be full with fluid (no air) then down to each caliper that you open, keep a couple liters of fluid in the bleeder and only drain out as much as the tank holds (from all 4 calipers). same procedure, different name bleeding/flushing. make sure the motive hose is full of clean fluid and fill the reservoir to the top to eliminate any air that might get in the system, clamp off the vent hose prior to attaching the unit. If your good, you can tip the motive unit on its side after your done and open a bleeder (left front) allowing air to push the fluid down the tube and close the bleeder when the level in the reservoir reads full, then there will be no mess when disconnection the cap.

[Flat Six]

Note: Bleeding and flushing are not the same procedure. Bleeding removes (compressible) air from the brake hydraulic system. Flushing replaces old fluid (which, due to the hygroscopic nature of brake fluid, has likely absorbed moisture) with fresh, new fluid. Of course you'll want to make sure you've bled your system once you've flushed with new fluid. Typical brake fluid flush interval is every two years, regardless of mileage.

[rusnak]

You can flush and bleed at the same time.

I too like to use different colored fluid, and prefer to put fluid in the bleeder, rather than air. It's better to not have to re-bleed the system if you don't have to .

Also, very important to release pressure at the bleeder tank, not at the MC reservoir, as the OP noted. That is so fluid is sucked back into the bleeder, not sprayed all over your trunk. If done this way, then the Motive is as neat and clean as can be.

[porschenut]

If you're flushing, you're completely replacing all the brake fluid. Bleeding means only removing enough to get the bubbles out.

Those who prefer to put the fluid inside the Motive will change their minds when the vinyl tube bursts under pressure and the fluid explodes all over your car's fenders, trunk and garage wall. I was one of those guys and will never, ever do that again. It is far better to use it dry (and you don't have to clean it that way).

[tmblackflag]

I have a set of ramps and no jack/jackstands at my apartment. Can I get away with driving onto rear ramps, bleeding, then driving onto ramps in front and bleeding there?

[James Brown]

yep sure, angle might be high but doable

[tmblackflag]

Excellent, will finally tackle this job tomorrow.

[tmblackflag]

How does the filter in the top of the MC come out? Need to remove to siphon fluid and don't want to break it.

[rusnak]

just pry it out with a very small screwdriver.

[James Brown]

be sure you clamp off the vent hose on the M/C

[dshepp806]

James notes an important piece, for sure! I NEVER put fluid in the Motive and take the time to release pressure and add fluid as necc'y to the MC reservoir (quite busy on a flush). I always lay down some polypropylene sheeting to cover the entire trunk area just in case. I make sure a water hose is nearby, too! Had no problems on several takes.

BEST!

Doyle

[Richwro1]

I didn't read these threads when I got my 87 3 yrs ago. Amazing how much brake fluid comes out that little vent house when under pressure. Emptied the motion bottle in 5 seconds. Never did that again!

[tmblackflag]

Access wasn't as great to the rear calipers as I had hoped so I'm in the process of getting a floor jack. While I research those (leaning towards hein werner 2 ton floor jack), can someone confirm if this is the hose i should be c-clamping? Say somewhere around the red arrow?

I tried to follow this house towards the firewall and can't see where it ends. Don't see how that could be an overfill house...

[SilberUrS6]

Originally Posted by tmblackflag

Access wasn't as great to the rear calipers as I had hoped so I'm in the process of getting a floor jack. While I research those (leaning towards hein werner 2 ton floor jack), can someone confirm if this is the hose i should be c-clamping? Say somewhere around the red arrow?

I tried to follow this house towards the firewall and can't see where it ends. Don't see how that could be an overfill house...

Well, since your car *IS* the best 911 color, I will answer.

Yes, that is the overflow hose.

[tmblackflag]

Then where the hell is that overflow fluid going? Hose heads straight for the firewall and then I lose sight of it.

[theclaw]

Hose works it's way to the front left fender in front of the tire somewhere near the front bumper. I found it by accident when I began to flush the system with my Motive bleeder and forgot to squeeze close the overflow hose at the reservoir. Had fluid dripping out of the front of the car. Doh!

[euro911sc]

Yup! always fun driving over brake fluid... its just so grippy! I use a small C clamp. Works fine.

I also never put fluid in my motive tank. Just refill the reservoir as needed.

If I am flushing the fluid it helps to have one of those kitchen suction thingies and suck out all the fluid in the reservoir 1st. Then refill the reservoir with your new fluid. Takes less time under the car bleeding it through the caliper.