brake pedal has no pressure engine boggs

[Noh0nda]

i have a 1989 240sx ka24e automatic and all stock.the brake pedal has no pressure it just sinks down. and when im pumping brake trying to get pressure the engine boggs down. also i have to drive like 10 mph because the brakes do almost nothing. the brake fluid is full and the level of fluid never changes

[XxS13LifexX]

Have you checked the vacuum line that runs from your brake booster to your intake manifold? Check for any cracks in the hose or points that may allow air to escape... replace hose if needed. You can also try replacing your check-valve as it may not be closing appropriately.. This is inline with the vacuum hose that connects to your intake manifold. should be just a foot or so from the brake booster.

[Noh0nda]

that hose is fine my braking problems started when i accidentally put atf in the brake master

[Lobo240sx]

You are going to need to bleed the brake system completely to get that auto trans. fluid out. It is the wrong weight.

Start from the right front, and work your way to the left front. If that doesn't check out, you may need a new Brake Master Cylinder.

[PapaSmurf2k3]

I'm wondering if the ATF chewed through the seals in the master, and your booster is sucking too much vacuum to try to move the piston inside the master too much (to no avail).
If bleeding the brakes doesn't work (which should be done passenger rear, driver's rear, passenger front, driver's front order btw), your next action would be to replace it and see how it is.
Also inspect the booster. If the master is leaking at all, then the fluids could have eaten through the seals in it as well. It might be worth replacing while you're in there if that's the case.

[ka24ejunk]

i see that you added atf to your master cylinder. sorry to say this but you ruined it. if you are lucky you might get away with bleeding it out and adding new dot 3. good luck

ka24ejunk