Ignition ON when using a Pressure Brake Bleeder?

[Berty_K]

Question in title. Proper brake bleeding require ignition (but not engine) to be ON. Does the same apply when using a pressure bleeder like the one Motive makes?

 

[OopsIBrokeIt]

I just tried this the other day, and I was able to push fluid through the system with and without the key in.

In the interest of making sure I removed as much fluid as possible, I ended up doing a first round with the key off, then turning it on and pumping the pedal a few dozen times before I bled each corner again.

 

[Drcoffee]

Fronts - engine off ignition off. Pump brake pedal slow and smooth. Try not to press brake to the floor. It could damage master cyl seals.

Rears - no brake pedal pumping. Open bleeder, turn key to accessory, allow brake motor to run until it stops, igintion off, repeat ignition on. Let the the truck pump the fluid.

 

[ArthurKotb]

I have a 2004 SE V8 and I'm in the process of bleeding mine now. I tried using a Mityvac brake bleeder on the rear lines but it wasn't effective.

I used a Mityvac 830 to draw most of the fluid from the reservoir front section, then refilled with Prestone DOT 3 MAX. I wanted to replace the fluid in the lines, since it had never been done. I used the brake pump for rear calipers.

I used a 17 oz. empty/clean water bottle with the clear PVC line from the Mityvac feeding through the bottle cap to the bottom, a couple inches of fluid in the bottle. I put the rear axle on jack stands, did one caliper at a time. I put the bottle above the axle, hose to the caliper bleed valve, opened the valve.

Ignition on (idiot lights on), engine not started, brake motor will run and stop. I pressed the brake pedal down and the pump ran. (If you do this too long the alarm beeps.) After about 6-7 seconds I let off the brake and checked the bottle and reservoir levels. (Do not let the reservoir go below minimum.) When I saw the fluid get lighter I felt the new stuff was in that line and did the other side. I had to empty the bottle once, refill reservoir twice for each side.

I tightened up the bleed screws, removed the bleed tube and bottle, removed jack stands and lowered the car.

For the front wheels I used the Mityvac, ignition off. Standard brake bleed; turn on Mityvac, open bleeder valve, draw fluid, close valve, check reservoir. Repeat on the other side. TIP: I use a small amount of beeswax on the bleeder screws to make stronger suction, fewer air bubbles.

I have a good brake pedal, no leaks.

 

[Berty_K]

I have a 2004 SE V8 and I'm in the process of bleeding mine now. I tried using a Mityvac brake bleeder on the rear lines but it wasn't effective.

I used a Mityvac 830 to draw most of the fluid from the reservoir front section, then refilled with Prestone DOT 3 MAX. I wanted to replace the fluid in the lines, since it had never been done. I used the brake pump for rear calipers.

I used a 17 oz. empty/clean water bottle with the clear PVC line from the Mityvac feeding through the bottle cap to the bottom, a couple inches of fluid in the bottle. I put the rear axle on jack stands, did one caliper at a time. I put the bottle above the axle, hose to the caliper bleed valve, opened the valve.

Ignition on (idiot lights on), engine not started, brake motor will run and stop. I pressed the brake pedal down and the pump ran. (If you do this too long the alarm beeps.) After about 6-7 seconds I let off the brake and checked the bottle and reservoir levels. (Do not let the reservoir go below minimum.) When I saw the fluid get lighter I felt the new stuff was in that line and did the other side. I had to empty the bottle once, refill reservoir twice for each side.

I tightened up the bleed screws, removed the bleed tube and bottle, removed jack stands and lowered the car.

For the front wheels I used the Mityvac, ignition off. Standard brake bleed; turn on Mityvac, open bleeder valve, draw fluid, close valve, check reservoir. Repeat on the other side. TIP: I use a small amount of beeswax on the bleeder screws to make stronger suction, fewer air bubbles.

I have a good brake pedal, no leaks.

Great- I'll give this a shot in a few days. Good tip on not using the pressure bleeder for the rears.

 

[ArthurKotb]

I've used only the Mityvac a couple of times and it just doesn't work well on the rear calipers. I let the pump do the work this time and it was a huge improvement. You don't need to push hard/far on the brake pedal. When you turn the key the pump builds pressure and stops. Then push down and you will hear the pump start. Hold for 7-8 seconds then release brake pedal (if there's a warning beep let go). Pump will run until pressure is up again then it will stop. Check the reservoir and the drain bottle.

On the fronts I found the beeswax (cheap, small jar of it in the cosmetics aisle where you find ointments, topical vitamin E bottles, night creams) helps seal the threads. I also pull or push on the bleeder valve and will find a sweet spot where the vacuum is best when Mityvac (bleeder) is running.

I replaced my rear bleeder valves. They were rusty where you connect the tube and making poor contact. They are a different size than the fronts. I also put beeswax on those new threads. I've had those bleeders rust so bad on another car I had to replace the caliper.

Good luck :wave:

 

[Shiftless Joe]

Yes, ignition on.

 

[Drcoffee]

FSM instructions for bleeding brakes

 

[ArthurKotb]

Odd that it doesn't specify a brake bleeding sequence. It says front first, then rear, left or right doesn't matter? I wonder if there is a change within the 4th gen model years