Brake pedal goes to floor when car is running

You can also gently tap on the metal lines and the pressure regulators with a small hammer to break loose any air that is stuck.

What kind of brake fluid did you use? Your car requires DOT4. The trouble you are having with bleeding the brakes is what made me buy a Motive pressure bleeder. It saves a ton of time and swearing. Makes bleeding brakes easy.

I made my own pressure bleeder with a boneyard reservoir cap and a quick connect air fitting. I just drilled and tapped the cap for 1/4" npt and screwed the air fitting in. Just turn the pressure regulator down to 15psi on your compressor and make sure the reservoir doesn't run out of brake fluid.

Kuutio said:

New mc it is. No air, nothing but pure fluid and once again even worse pedal feeling. Still brakes work but ehh

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You probably have air trapped in the lines just past the master cylinder. 940 master cylinders have bleeder ports on the side of the master cylinder in order to remove the trapped air. Bleed each of those ports before bleeding any of the other ports at the calipers.

VB242 said:

If the booster is bad it will be harder to press the pedal not easier. You either have a bad MC or air in the system

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This is not always true. My wagon developed a leak in the booster, pedals were solid with no vacuum, with vacuum they were spongy as all get-out. Stuck my head under the dash, pushed the pedal in 1/2" and heard a constant hiss, which shouldn't happen. Given the booster was deemed failed at that point, I swapped in a Cardone which leaked even worse. Took a Mityvac to the yard, found one that held vacuum, pulled, installed in mine, pedal came right back, been flawless since. No other changes to the system.

A vacuum booster will never be the source of spongy brakes. Take a look at a cut away of a braking system. The booster either applies assist to the braking force, or, it doesn't. There is a solid connection all the way to to back of the hydraulic piston in the master cylinder once the pedal is pushed far enough to close the valve on the booster.

https://www.google.com/search?sourc...gQIBxAB&biw=1260&bih=713#imgrc=8OQCnnEAOg24dM

2manyturbos said:

You probably have air trapped in the lines just past the master cylinder. 940 master cylinders have bleeder ports on the side of the master cylinder in order to remove the trapped air. Bleed each of those ports before bleeding any of the other ports at the calipers.

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Did try that and got no air out.

I will be changing mc and if that doesnt work then i have air in the system but i have tried to get that air out multiple times through every bleeder i could find and driving the car between bleeds. Also braked so abs gets going and didnt get any result that way either. Also yes im using DOT 4. Pedal does feel weird but it returns nicely. It doesnt have that feeling when you have air in the brakes. Its more like you have 2 cylinders and the 2nd cylinder is leaking so building pressure feels weird.

dl242gt said:

You can also gently tap on the metal lines and the pressure regulators with a small hammer to break loose any air that is stuck.

What kind of brake fluid did you use? Your car requires DOT4. The trouble you are having with bleeding the brakes is what made me buy a Motive pressure bleeder. It saves a ton of time and swearing. Makes bleeding brakes easy.

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Would love to have one but rarely i need one so thats why i dont have one would love to have one that our school here had where you push the fluid through. I think thats what you are talking about too ?