GMT 400 Hydroboost swap

[vince72]

Any good information on modifications needed incase the stock pedal is used?

 

[vince72]

Hey Guys,
I am going to attempt to install the hydroboost this weekend & wondering how the lines go with the 2500 hd pump? The hydro unit I have has two threaded lines and one return line, the back of the new pump has only one threaded insert and two open lines. Am I missing parts?

 

[Supercharged111]

Hey Guys,
I am going to attempt to install the hydroboost this weekend & wondering how the lines go with the 2500 hd pump? The hydro unit I have has two threaded lines and one return line, the back of the new pump has only one threaded insert and two open lines. Am I missing parts?

Did you also get the HB specific PS lines?

 

[vince72]

I got the lines that car with the hydroboost, three lines two threaded and one with a clamp. Is there something else needed?

 

[Supercharged111]

I got the lines that car with the hydroboost, three lines two threaded and one with a clamp. Is there something else needed?

Nope. One goes to the PS pump pressure, one to the steering box, the other is the return to the PS reservoir. Did you grab the cooler too? Or did your truck already have one?

 

[vince72]

I did not get the cooler. What about the second non threaded line? Not sure how to run this one

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[Supercharged111]

I did not get the cooler. What about the second non threaded line? Not sure how to run this one

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One is the return from the box/cooler, the other is the return from the HB.

 

[Jesse_Wenting]

The high pressure side of the system is all threaded lines, this runs from the pump to the HB and then to the steering gear. The low pressure side consists of two lines; the hose barb from the HB to the pump reservoir, and a threaded line from the steering gear to the second barb on the reservoir.

There's diagrams online about which ports on the HB and gear are for which lines. If you're going to run a power steering cooler, put it on the return line between the steering gear and the reservoir. Fluid only flows through the HB return line when the pedal is being depressed IIRC.

Any good information on modifications needed incase the stock pedal is used?

Look through the first few pages. I remember seeing some info about this, I'll try to find it

 

[L31MaxExpress]

I'm trying to figure out who says on the 98 2dr tahoe the brake pedal is different, I took the pedal off of I believe a c3500 1998 and comparing the two they are both the same, part no. 15732200 for both of them only the bottom 5 are different and I see no difference side by side. Do you guys know how misleading the pedal thing is and the amount of energy it takes to get that out from around all that crap underneath the dash. Wasted a whole Saturday on that pedal when I didn't even need to change it and could have just concentrated on getting the hydroboost unit. You guys should have said 95 back pedals are different cause it is nothing easy about this hopeful upgrade

I have never seen the same year vacuum boost application take the same pedal as the same year hydroboost setup. On my 97 Van the pedal absolutely was different. Pedal on the left was from a 99 van that was the pedal donor. The one on the right was the pedal in my vacuum boosted van. My G20 van and my 99 Tahoe also used different pedals. Both came out of diesel donors. If you try to connect the hydroboost to the vacuum pedal, the pedal will sit way too tall.

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[Supercharged111]

I have never seen the same year vacuum boost application take the same pedal as the same year hydroboost setup. On my 97 Van the pedal absolutely was different. Pedal on the left was from a 99 van that was the pedal donor. The one on the right was the pedal in my vacuum boosted van. My G20 van and my 99 Tahoe also used different pedals. Both came out of diesel donors. If you try to connect the hydroboost to the vacuum pedal, the pedal will sit way too tall.

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All the trucks I've put eyes on have the exact same difference in the pedals.