Tabor

I just finished rebuilding all of my calipers and replacing my rotors/pads. I have pumped about 1 1/2 litres of brake fluid through the system with my power bleeder and my pedal is still spongey. Any suggestions? Do I need to do some "manual" style bleeding? Thanks.

jim968

Tabor, dunno if this'll help; I used a piece of clear tubing over the bleed fitting, going into a catch bottle, so I could see the air (and crud) in the fluid coming out. You might want to try the same. Start at the right rear, when it's clear, go to the left rear, then the right front, then the left front.

BTW, are you bleeding single or four-piston calipers? If four piston, bleed inthe order above, doing the outer fitting first on each caliper, then the inner.

Jim, willing to add to anyone's confusion

Rog

Hi,

two things that have often helped me is to (at each corner) place a slat of wood between each caliper and rotor. This pushes the pistons back in the calipers, reducing system volume. That means a given volume of delivered bleeding fluid can directly replace a larger percentage of the system's volume, thus increasing the odds of getting out all the air.

Even then, a brief drive or two around the block will usually force a lot of air to collect at the high points. You can then burp out a bit more air at the MC and each corner's caliper.

How are you using the power bleeder? The more volume of fluid one moves, and the shorter amount of time it is moved in, the better the chance of expelling any given bubble out the bleeder before the buoyancy can cause the bubble to rise to some local high point again. That can help a lot.

Did you just do each corner once?

hth

roger

Tabor

No, I bled each corner 3 times.

How do you burp the master cylinder?

951Tom

Did you bleed the master cyl separately? If it ever ran dry, this needs to be done. Then you can bleed the rest of the system normally.

Tom
'87 951
'86 Supra

Tabor

No, I didn't. How do you do this?

doyle

I replaced my calipers and added stainless steel lines in one shot. I bled the system with super blue and it took me about 30 times to bleed all of the air out and get the pedal where I liked it. I tried a mityvac and was not impressed. The best solution was to use a clear bottle and a hose, have someone pump the pedal and bleed each corner. Overall, I bled it 30 times in 2 weeks. I got so good at it, I could bleed all 4 corners in about 5 minutes without taking the wheels off. You just need someone to pump the brakes. It is a pain in the a$$ but worth it in the end!

Tabor

Thank You Doyle. That makes me feel better. I don't mind bleeding it 30 times if I know it will fix it.

adrial

I think I'm in a similar situation..although I'm not quite sure if I really need to bleed it some more or not...I really never stomped on the brakes before. It doesn't seem to feel right though...

When bleeding the clutch slave I let the pressure bleeder get too low...and got air (a lot) in the system. Less than 15 seconds of bleeding got fluid flowing solidly through at the clutch slave. The clutch feels OK, maybe a little on the soft side.

Clutch and brakes share the same fluid, right? So do they share the same master cylinder? Either way I'd like to "burp" the master cylinder(s) and then maybe bleed it some more.

The ATE super blue that I used, I left in the pressure bleeder (oops). So I'm sure its absorbed some moisture, should I order up some more from paragon or is this stuff still OK to use?

EDIT: In the factory manuals it says, "When bleeding the system, depress the brake pedal several times with bleed valves open to expell all air bubbles form the brake master cylinder." For the bleeding process..they use some sort of techno electronic gizmo.

951Tom

Tabor,

I've seen kits in the autostore to do it. You remove the metal lines from the master cyl and screw in short hoses that empty back into the resevoir. Then fill with fluid & pump the pedal to get the air out. Reconnect the metal lines & bleed normally.

Tom
'87 951
'86 Supra

Tabor

Okay, I am farmiliar with bench bleeding. However, how do you connect the metal lines after bench bleeding the master cylinder? Won't you just contaminate it with air?

pikey7

I had all of the calipers off my car to repaint, relpaced the front lines with DOT stainless, and added speed-bleeders

I used a Gunson pressure bleeder. It uses the front tyre pressure to force the air out/fluid in.

I did each corner once. It took longer to take each wheel off than it did to actually bleed the system.

Now its just great!

Rog

Hi,

That's the trick, you're sure to reintroduce a little air, but it's better than starting out with a bunch in the MC.

Back to the old master cylinder burping, a little light (very short stroke) pedal fluttering will allow a bit of air to shake off the piston in the mc, and float up into the resevoir. Anything more than a short stroke won't help.

Bleeding is rarely fun, and not always consistent. Certain MC/caliper combinations are a bite, and some pretty easy. If it's any consolation, the brembos and Ates on Porsches are worlds easier than the Ates on 70s beemer bikes. Those are just horrible.

Good luck
roger

951Tom

Having only bleed the system normally, I wondered that too. I think if you put the m/c cap back on before removing the little bleed hoses, the fluid will stay in there. Do one hose at a time. I'd have something to cap off the brake line near the calipers when you remove the brake hose so as to keep fluid in there & air out. A pressure bleeder is a must have in my book.
Tom
'87 951
'86 Supra

jim968

Tabor, one other thing that hasn't been expressed in so many words... pressurize the system (power bleeder or helper). Then just barely loosen the tubing fittings on the master cylinder, enough so a bit of fluid seeps out. This may help get any air that's stuck in the upper ends of the lines. Kinda like using the fittings as bleed screws.

Jim, also now a great believer in the Motive Power Bleeder...