Brake pedal pulsating need help!!!

[biggieB15z33]

Ok I did an sr20det swap on my vert and when I apply the brakes and I keep them pressed and rev the engine the brake pedal pulsate/moves up and down, when I rev the engine the brake pedal pushes my foot upwards and when I stop reving the brake pedal returns to the original position, all this is while the car is parked, I didnt have any problems when I had my KA swap,any ideas or solutions????

[mechanicalmoron]

The brakes are vaccum assisted.

When you rev, vaccum drops, and there is less assist.

[OnTheChip]

Make sure the check valve is in the brake booster hose.

[biggieB15z33]

Originally Posted by OnTheChip

Make sure the check valve is in the brake booster hose.

I checked and the hose is connected to the check valve bro

[mechanicalmoron]

Originally Posted by biggieB15z33

I checked and the hose is connected to the check valve bro

You can blow in the check valve to make sure it functions. (obously, it should blow towards the manifold, and not towards the booster)

But yeah.... my KA does it. Any car with vaccum assisted brakes will do it. Maybe you're feeling it more strongly because there really is no vaccum if you're revving into boost. And if the check valve doesn't work right, you could be forcing boost into the booster, and actually having the assist fight you instead of help. At least, that's my understanding of it.