Lack of Power Steering/Power Brakes at idle

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DeepEmissions

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good afternoon TYF crew, I have a 2005 Yukon Denali XL AWD, 6.0, basically fully loaded from the factory including the air ride suspension, if that part helps.
New pads, rotors, and 2 new calipers replaced less than 100 miles ago.

So, truck wasn't very well kept up with before I owned it, lotsa little bugs and stuff we've been working on addressing, one was a Power Steering fluid leak at the Brake Booster.
I had the truck in a friends shop one day and decided to tackle it, until I seen it was bolted to the firewall from the inside of the cab, decided that wasn't something I wanted to deal with today, in the midst of having the booster separated, we checked to see if there were any obvious issues that might cause a leak, seeing none, we applied a very thin layer of RTV silicone to the 2 halves and put it back together. Viola! The leak stopped! Fast Forward a month or so later, a few trips after this temporary fix (we only drive it when we need to take all the kids and adults, only has 5000 miles since we've owned it almost a year) it's about 10 miles from our house to the first red light in our small town, so by now everything has gotten up to temp, I go to hit the brakes, truck is near idle due to traffic, brake pedal is rock hard and steering is also hard. Queue the wifey and I having a panic attack! quickly realized that engine speed gives me power back to the pedal and steering. Do an about face and take the truck home.
I haven't really messed with it since but we have a trip planned in about a month and we're gonna need the room, no truck equals no trip.
I still have the new brake booster, I'm sure that probably SHOULD be changed, but is that the actual problem, or could it be something else I should look into or order before I begin this job?
 

Fless

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Your JH2 RPO code and your wording tells us that you have hydroboost brake assist. While I agree that the brake booster may need to be changed and may be a partial cause of the issue, the power steering pump pressure and volume has a direct effect on how much assist is available. Have your mechanic check the PS pump pressure to see if it's up to spec.

EDIT: how is the level and condition of the power steering fluid?

 
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DeepEmissions

DeepEmissions

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Your JH2 RPO code and your wording tells us that you have hydroboost brake assist. While I agree that the brake booster may need to be changed and may be a partial cause of the issue, the power steering pump pressure and volume has a direct effect on how much assist is available. Have your mechanic check the PS pump pressure to see if it's up to spec.

Well I don't have a mechanic per se as I generally work on my own stuff, but hydroboost is new to me, what do I need to check the pressure on the PS pump myself?
 

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