Sean Betts

I had a leaky hydroboost. Bought a rebuild kit and changed 2 o-rings. It was very simple and straightforward. Reassembled everything pumped the breaks. A little spongy, no big deal as I was planning on bleading them. Start the truck to look for ps leaks. The break pettle was sucked to the floor and will not return. Turn the truck off and pump the breaks. After 15 pumps the breaks start to come back up. I'm stumped. Any ideas?

Nice I might need to pick one of those up at harbor freight.

Fixed... Found a good sized leak on the boot that connects at the motor intake. The sound I think is coming from belt tensioner. At higher rpm 2k or more the belt shakes like mad at the tensioner.

What should I be looking for on the exhaust side?

Where is the overflow valve located on the vp44?

So that hissing is an air leak. I did think that the valves on a cylinder should never have intake and exhaust open at the same time. I figured it might be some funky diesel thing.

I'm excited this is sending me in the right direction. So I just want to confirm.... The motor should not have any leaks when off and I pressurize the intake side of the turbo. I heard some hissing that's why I used the can of chili because I figured that the hissing was from some valves being open.

I'm hoping someone knows about this. Can a map sensor affect the output of the liftpump? I think the stock liftpump has a hi and low setting. Will a map sensor giving bad reading defuel the vp? Or is it working in reverse and sensing boost and then adding fuel?

I did stop it before the intake horn. The grid heater gasket seems too simple. I will be checking it as soon as the sun comes up. So another question for you. When I pressurize the intake side of the turbo will air hiss through the valves and out the exhaust? If not this idea is genius and could really set me on the right path.

Tested all that. Built a pvc contraption that let me add air via air chuck. (Turned down to 30 psi. Then the other end I found a can of chili that fit perfect. Clamped them down and added air. Its all tight. I'm all stock and can get 19 psi of boost.

Any advise where to start looking?

on YouTube

Can you open this? https://www.dropbox.com/s/droxfksotnqym1u/20150929_210354.mp4?dl=0

Can I upload a video on this? I can put a YouTube viedo up or post a Dropbox link. Give me 20 minutes.

The sound is like a turbo bark but for 20 second or so as the boost is increasing or decrrasing. My boots and intercooler are not leaking. Did a pressure test to 30 psi and it held air pressure.