i just got a 92 eg hatch with a b20 swap. when i hit the brake pedal it goes right to the floor. i put a new master cylinder on aand bled everything and still no pedal. it gets a little bit of resistance when the car isnt running but right when i start it up the pedal loses all resistance. ther are no loeaks anywhere and relatively new stainless lines. while driving i can feel the brakes trying to work if i pump them but its n ot even close to enough brake to stop so i've been ebraking it. please help its my daily driver

 

check the diaphram in your brake booster make sure that its not blown out, i would believe it may be ok because you would have pedal pressure just no vacuum assist.
Just a thought...

 

If there are no leaks, then you almost surely still have air trapped in the system. Keep bleeding the system in the proper wheel sequence. I use this tool that cost me $4 at harbor Freight Tools.

 

i bled the system 2 more times and then gravity bled it for about an hour.... still no pedal. when i push the brake i can hear air comming from the intake im gonna try a new booster on saturday but my booster now should be working fine. thanx for the comments so far! im pretty sure theres no more air left in it but still no pedal

 

When i did my brake tuck i had to replace my brake master cylinder because ive heard that you can blow the seals out if you push the pedal too far to the floor, either way upon hearing this i replaced the master and it did fix my problem. When you bled your brakes did you push the pedal all the way to the floor? im refering to the first few times when there is no pedal pressure.

Just trying to think this through.
You sure you dont have a leaking brake line somewhere? If your getting fluid at the bleeders when your bleeding the brakes you would almost have to have some sort of pedal pressure due to the fluid being pushed into the calipers when the bleeders are closed. otherwise there would be no pressure to push the fluid through the bleeders.

 

when first starting the bleeding there is no pedal at all but after the bleeding there is pedal pressure. once i start the car all pedal pressure goes. iv had the car on the lift in my detail shop and there are no leaks whatso ever oil brake fluid or anything. it just seems like once the car turns on the brakes dont like me anymore

 

The pedal hits the floor only with the engine on because that's when the assist from the brake booster kicks in. Either there's air still in the system or the new MC is bad.

 

Im going through the same thing right now. I have a 90 Hatch with a B18 swap and i fixed my sliders on the caliper's bought brand new drums and hardware put a new mc on and just blead them and i still have no pressure with my pedal when i start the car. Please i need help im stumped...

 

i know from personal experience, that if the mc isnt bench bled, then the pedal would still go to the floor. even after bleeding the system a few times... ive had to take the mc back off, bench bleed then rebleed the system... which has also caused the problem where there is pressure with the car off and after starting the pedal goes to the floor... maybe try to bench bleed

 

Thats exactly what happened when my brake booster was bad.

 

would i need a different proportion valve if it has rear disc swap?

 

i feel stupid for not noticing this earlier but the guy i got my car from put the calipers on backwards...... good brakes now thanks to all for the help