Brake bleeding tips and tricks....

[chrisbruck]

So if ever get my parts from Fed Ex, I will soon have a brake system to bleed...

Replacing master cylinder, reservoir and rebuilding calipers. Bled the system before I did all this so I know the general procedure. Going to use a Motive pressure bleeder at about 10 psi.

So, any hints on where the air bubbles tend to get trapped in the system when flushing the whole system? I plan to bench bleed the master and use a fair amount of fluid and go through each caliper a couple times. Plan to tap each caliper with the bleed nipple open to jar the bubbles out.

Any other places notorious for air to get trapped I should look out for? I'm hoping to get it right the first time. I plan on doing it again after driving a bit as well.

Just looking for the tricky areas before I get started and get dirty!

[aston@ultrasw.c]

Sounds about right.

Don't get all crazy about getting it perfect on the first try. Like you said, wait a few days and do it again. I think tiny bubbles coalesce over time making them easier to bleed.

[CCM911]

I generally pump the motive to at least 15PSI if not higher, and have had no issues. I know a bunch of folks that do the same as well. 10PSI will take forever to bleed the system.

FLAME SUIT ON.

[CCM911]

And don't forget to block off the breather hose at the MC. Ask me how I know.

[James Brown]

all good info, increase pressure works good! the brakes might not feel like all the air is out, just drive around slowly for a few miles pumping them to seat the piston O rings, the will move a few .000 every time till they get set, then re bleed and they should be good, mine always took a week of normal driving till the pedal was firm at the top, yeah watch that vent hose, i use a pair of hemostats to pinch off the hose.

[McLaren-TAG]

I was surprised how little brake fluid it took for a complete flush. I changed fro whatever was in there before to ATE blue and used considerably less than one can.

10 lbs was plenty for the flush and I recruited my wife to pump for the two or three rounds of fine tuning.

Since you're doing the entire system YMMV.

[ivangene]

TIP:
DO NOT put brake fluid in the bleeder - it just makes a heck of a mess - I use the bleeder as an "air" system and just release the air, add fluid to the MC and repeat

you can gavity bleed a lot of air out - open the bleeders and just pour fluid in the MC

put a little piece of clear tubing on the bleeder and catch the runoff in a can/bottle or oil drain pan - makes clean up easy.

spray the area with brake cleaner after bleeding to keep from having a paint remover left on your new calipers/control arms ect

[chrisbruck]

All good tips.... sounds like I'm prepared pretty well. That is, of course, I get my parts and get it all back together!

[KFC911]

After trying both methods, I now keep the pressure bleeder "dry" and pump to 14 psi with great results. When I replaced my brakes with a 930 setup, I didn't even bother to "bench bleed" the m/c and it was still painless to go around the car a couple of times (two bleeders per caliper on mine) while only having to top off the fluid reservior a few times. Since you have an '87, don't forget to bleed the clutch also!

[gregwils]

Make sure the calipers are on the correct side of the car with the bleeder toward the top. Start at the farthest from the MC and work toward the closest - RR, LR, RF, LF.

I use speed bleeders and get a hard pedal every time.

[wildcat077]

You shouldn't have any issues if you follow the above procedures ... i installed a complete new brake system including calipers with dual bleeders,new lines ,23mm master and i went through a little over one liter of new fluid before everything was right on !

Probably went around the car three times but with a Motive bleeding and flushing brake systems is a breeze !

Cheers !
Phil

[midnight911]

classic two-man method FTW.

i have motive and i like it but the pressure it builds is too weak to get those stubborn air trapped in the system. motive works great flushing fluid with the system with very very little air in, if not none...

[DRACO A5OG]

Also check all your brake lines not just at the calipers but behind the stone guard at the t & elbow connectors, A leak there, you will never get the brakes hard:

[RWebb]

flush & replace with new fluid every 2 years NO MATTER how few miles you drove

inspect the hoses (squish them - don't just look), the lines (as per above; also look for damage from rock chips, debris) & the calipers and tires periodically

replace all brake hoses with new rubber every 6-10 years