Another brake bleed/MC/Booster problem thread

[infernosg]

Originally Posted by JL1RX7

I have used them in the past and got great pressure reading etc. But still had the same issues you're having. Went back to the old tried and true and got a few bubble out.

It shouldn't have picked up much water then. Just sucks that the fluid attracts water so no shelf life for it at all.

I'll give it a try. I'd think with the amount of pedal movement I'm getting there'd be a pretty big bubble somewhere.

Originally Posted by Pete_89T2

It could be, are you saying that you don't put any fluid in the bleeder, and just use it to pressurize the fluid in the MC reservoir & system? You'll never manage to flush out all the air in the system with that small a volume of fluid.

Normally for a fluid flush & bleed, I'll dump a full quart of fresh brake fluid into the power bleeder tank, and it will take almost all of it to get to the point of zero bubbles and a solid pedal.

To avoid the mess at the end, do the following when you're satisfied the last brake has been fully bled:
1. Tilt bleeder tank such that the feeder tube at the bottom is no longer under fluid.
2. Crack open the bleeder screw on that last line, and let it slowly bleed out until the fluid level in the MC drops to the full line, then close the bleeder screw.
3. Carefully depressurize the bleeder tank by *slowly* loosening the pump piece from the tank. Make sure the tank is still tilted at this point so the feeder tube at the bottom is not immersed in fluid.
4. Now you can remove the adapter from the MC without the mess.

Yep, that's what I've been doing. I'll let the fluid in the reservoir get to the "LOW" mark and then fill it up again. I've certainly flushed more than a quart through the entire system by now. What pressure are you using with the Motive bleeder? Also, how much are you opening the bleeder screws? I've used anywhere from 5-20 psi and I've let the fluid come both rushing and slowly trickling out.

[Pete_89T2]

Originally Posted by infernosg

Yep, that's what I've been doing. I'll let the fluid in the reservoir get to the "LOW" mark and then fill it up again. I've certainly flushed more than a quart through the entire system by now. What pressure are you using with the Motive bleeder? Also, how much are you opening the bleeder screws? I've used anywhere from 5-20 psi and I've let the fluid come both rushing and slowly trickling out.

Every time you open the MC to add more fluid, you introduce another opportunity for air to get into the system. As you pour in fresh fluid, sometimes the simple act of pouring can snag a bubble or two of air along the way.

I'll normally pressurize the tank to 10~15psi. When opening the bleeder screws, I just crack them open slightly at first, then slowly open them up a little bit more until I get a steady flow out. When the flow of bubbles seem to be slowing down, I'll close the bleeder and then wait a minute or two. Then I keep repeating this open/close process until nothing but fluid comes out. After bleeding each wheel, I'll check the tank pressure and pump it up as necessary to keep it as close to the pressure I started with as possible.