jeff49

Ok, is it normal to run 1pt through the right rear bleeder before fluid and bubbles stop.I put 2qts in bleeder as instructions say and turkey basted the master before presureizing system.pumped it up to 20psi and bleed rr first.Im afraid of ruuing out of fluid and damaging something.2001 A4.There is still a liitle fluid left in bleeder not much.Thanks Jeff49

Falcon

The fluid should never stop coming through the bleed nipple. Usually the bubbles stop after a couple of seconds, assuming there is any air in the caliper.

It normally takes ~1 liter to flush the whole system (all 4 calipers). Using a little more is no big deal.

Cobra4B

Most only use the motive to pressureize the master... add the fluid on your own.

Miaugi

In answer to your question "Falcon" was correct in that the bubbles usually stop in ~3 - 6 seconds and then that caliper should have no more air in it.

If you wish to flush the whole system wait until you see the fluid turn clear (or at least clearer) as that should indicate the old fluid has been purged from the system.

When I use my Motive bleeder I use it dry (no brake fluid in the unit) and I keep an eye on the master cylinder reservoir to make sure it doesn't get too low. Most here report when using the Motive bleeder they use at least 20 lbs. and many use 25 lbs. (I use ~25).

I know that many guys here also put brake fluid in the Motive as you did but as I said myself and others do not, can't say which is better as I guess it's a personal choice.

BTW, if you do not get all the calipers done and you think you will run out of fluid you can stop where you are and finish the job the next day, this should not be a problem.

Hope this helps?

elh0102

Like others, I prefer using the tank to just pressurize the master cylinder, topping it off as needed. It's just less of a mess by not filling and then draining and drying the bleeder bottle. If you should let the MC run dry and get air in the line, no damage done, just bleed it out. Just don't go roaring out of the garage until you have a full, solid pedal.

davidfarmer

You may need up to 30psi to fully flush the system. 20psi can be really slow, and 30 shouldn't blow out your seals.

Anyway, you shouldn't have ANY bubbles in your system. If you do, they will have floated to the top and come out right away. If you keep getting bubbles, there is a leak somewhere.

It sounds like you were asking about emptying the master. I empty it as far as I can with a baster/syringe, then refill with fresh fluid. As long as you don't pressurize it while empty, you won't get any air into the system.

The main goal of bleeding brakes is to get old, hydrated fluid out of the system. Brake fluid absorbs moisture, which lowers it's boiling point. If you are getting lots of bubbles, you need to use a better fluid, better cooling, or figure out where the mechanical problem is.

vms4evr

20-30psi? I've been doing bleeds with the Motive unit and only using about 15psi tops. Why so much pressure? And are you sure you can run 30lbs without causing issues?

94ZR1#444

The bubbles may be coming from air getting into the bleeder tubing, it all depends on how you hold the tubing. 1pt is too much, should only be about 10-15 seconds max at around 15 PSI max. Any more PSI is too much. Don't put fluid in the Motive tank, just add fluid to the MC and keep a close eye on it so that it doesn't draw in air.

jeff49

Yes.I twisted the bleeder tubing and the bubbles stopped and fluid was clear.It was a hassle cleaning the tank.Next time I will just pressurize the System and 15 to20 psi worked just fine Thanks for all your help. Jeff

Miaugi

sothpaw2

How much should we be opening the bleed screw--if you open it too much, can you let air in even with the 15 psi motive? Also, if 15 seconds is a good number, can you just forsake the tubing and let the fluid flow out into a container for 20 seconds and call it done?

Thanks

94ZR1#444

There's no way you're gonna suck air in with 15 PSI attached to the Master Cylinder. I only crack open the bleeder valve a very small amount, just enough to see fluid flowing. If there's air in the line, it'll come out quick with 15PSI. I keep the bleeder valve open until I can see a change from yellow (dark/bad fluid) to a clear (Good/fresh) fluid. 15 seconds is MAX, I can usually get a caliper bled around 7 seconds or so, just make sure you see a color change in the fluid and you keep an eye on the MC fluid level.

HTH