sstrickstein

I've got an 84 928s and a 86 944 NA as well as a 00 996 cabriolet. Today I power bled and flushed the brakes on all three cars. Total time was only 2 hours! I've got speed bleeders on the 944 but this is even easier than those! I also replaced the pressure per portioning valve in the rear line of the 928 that's been leaking. We have a car business so I bought the professional kit made by mighty vac sold at napa. .

sstrickstein

Oh but speed bleeders don't work with a power bleeder. You've got to remove the bleed screws totally.

gcthree

Not true! Just bleed my completely empty system with a power bleeder. Just for good measure, I finished with 4 pumps of the brake pedal on each speed bleeder, but the power bleeder with 14psi worked perfectly.

sstrickstein

I had it pressured up to 15 lbs no go had to pump foot to get them to bleed

Mrmerlin

Warning using over 10 PSI can possibly cause the reservoir to blow off the MC ,
proceed with caution .

NOTE pressing the pedal of the MC full stroke can cause the seals to be damaged ,
as the piston will be traveling over unused areas that are usually corroded this will cut the seal.

It will become evident if this has occurred as the pedal will begin to lose its pressure,
and it will also become lower till the brakes apply

sstrickstein

Yeah that is what I've read. I plan to replace the speed bleeders back to stock and rebleed. My peddle on the 944 isn't what I like.

gcthree

Guess that I got lucky.... I have a new master cylinder so no worries about corrosion, and I suspect the new seals on the reservoir helped on the pressure.

I've used Speedbleeders on a series of my cars and not only do they simplify the bleeding process, I've found that I always get a real good 'pedal' using them.

sstrickstein

I too have had good luck with speed bleeders. But it seems that they don't like to work with a power bleeder.

dr bob

The speed bleeders have a spring that maintains the seal in the speed-bleeders unless there's more pressure in the system. Your foot has, let's say for discussion, a 10:1 advantage on the master cylinder piston. The diameter is 19mm for discussion, so the 2.25 hydraulic advantage times 10x mechanical advantage hives you the system pressure for every pound of pressure you put on the pedal. Engine running and booster working? Figure that in too. Seems like about 4 lbs of unassisted pedal is the same as what 10 PSI in the power bleeder gives. Not much pedal effort needed, it seems.