Pwr Steering / Brake relationship?
 

Would there be any Chevy Pros out there that can tell me if, or what the Pwr Steering / Brake relationship is on an 05' Suburban 2500 / 4X4 with the 8.1 is? I took mine in a while back for a simple brake line repair, which turned into the replacement of ALL the brake lines throughout, master cyl, and brake booster. Just so happens there was a power steering leak, so I had em swap out the reservoir & pump as well. But no matter how much "bleeding" they did, they couldn't get rid of that power steering "whine". Low & behold, the brakes are all spongy again and the peddle goes to the floor. A BMW mechanic friend said some of them 2500 Cheby's has some sort of relationship between the two. Is there anything to that statement? Thanx in advance for any knowledge offered.

Your friend is referring to the GM hydro-boost system. The brake booster gets its assist from the power steering pump hydraulic pressure.
You'd have to check if you have a vacuum booster or the mentioned hydro boost.
I have a power steering leak and I think it may be at the hydro-boost booster.

A spongy pedal and pedal to the floor indicate air in brake lines and/or a bad master cylinder.
The PS assist hydraulic system and the brake hydraulic systems are separate and do not intermix. They use different fluids.

Thank you. Follow up.......If a Brand New Power Steering pump/res was installed at the same time as a Brand New Brake Booster, but the Power Steering pump/res was not bled correctly and/or was simply a faulty pump right out of the box, could said Power Steering pump "cause" said Brake Booster to "Fail"?

Not in any way I know of. The PS pump only supplies the power assist via hydraulic pressure. A blown pump, power steering hose leak, or broken belt would only result in a stiff pedal due to no assist. This could cause a condition that could make it hard to stop the vehicle
There is a built in safety in case of a loss of hydraulic pressure. A built in accumulator should provide at least 2-3 pedal applications, each decreasing in assist, to stop the vehicle. After that, the brakes would be manual in operation.

Thanx 3Js,
. I s'pose the word "assists", along with they're BOTH brand new and BOTH failing Simultaneously is what's throwing me off & tricking my brain into thinking there's more of a "relationship" between the two.