Hydroboost power steering pump difference

[73 cheySuper]

Okay, another concern on the hb conversion to my '73. Backstory, I stole all the hydroboost components off a '89 V3500, including the pump. I wanted to use my old pump, non-hb that was original to the '73, but it was missing the second port on the reservoir. I also needed the pulley, double v, that was on the '73. Rather than mess with pulling the pulleys, just decided to swap the reservoirs and use the '89 remote, or detached reservoir. After disecting them, noticed the part numbers are different, even though they will physically swap without issue. Then, I asked our new genius Ai option if hb required a different pump.....Ai says yes, the line pressure is greater. Then I thumbed around the net and most have 0 issues with a non-dedicated hb pump used on their hb.
Okay, I can use either, both are good, bought an Edelmann reseal kit, but the biggest setback, providing I decide to use the hb pump, is the pulleys are different. The hb pump, later version, uses the pressed on pulley, 3 groove, which looked like hell to start with and I pretty much destroyed with an attempt to remove it with heat and the wrong puller. I can easily remove the other pulley, the threaded type. So, I have to ask.....is it even necessary? or can I just use the older pump, non hb?? If not, I have no idea how to get the proper pulley to press on that hb pump shaft.

 

[xm20k]

Just use your stock PS pump as long as it has good pressure and isn't leaking or sucking air it should work just fine. The bracketry you already have and if you ever need to replace the PS pump it'll be easier to get/swap out.

 

[Ricko1966]

Swap the outlet fitting it controls pump pressure. You'll need a new hose or adapters.

 

[Turbo4whl]

This is an AI overview:
Power steering pumps designed for hydraulic brake booster (Hydroboost) systems typically feature higher pressure and slightly higher, or more consistent, flow rates (GPM) compared to standard power steering pumps to ensure both systems function effectively, especially at idle. While standard pumps often operate around 1,200 PSI, Hydroboost-compatible pumps generally deliver a maximum pressure of 1,450-1,550 PSI or higher to handle the increased load of braking, particularly in heavy-duty or diesel applications.

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Key Differences in Flow and Pressure:

• Pressure Requirements: Hydroboost pumps are designed to operate at higher pressures (approx. 1,450-1,550+ PSI) because the brake booster and steering gear operate in series, increasing total pressure demand.
• Flow Rate (GPM): While a standard pump might work, a dedicated Hydroboost pump often has a higher flow rate (approx. 3.0-3.5 GPM) to prevent a loss of steering assist while braking.
• Return Lines: The most visible difference is that hydroboost-compatible pumps often feature two return ports on the reservoir—one for the steering gear and one for the brake booster—to manage the increased return fluid volume and prevent backpressure.
• Idle Performance: Hydroboost pumps are often tuned to maintain better pressure and flow at low engine RPM (idle), whereas standard pumps might experience a "hard pedal" or sluggish braking/steering if they cannot maintain high output at low speeds.

Important Considerations:

• Fluid Aeration: High-flow pumps (over 2.6 GPM) can cause foaming if the reservoir does not properly handle the fluid return. It is crucial that a Hydroboost system uses a reservoir designed to de-aerate the fluid, often recommending two return lines rather than a "T" fitting.
• Compatibility: While some stock pumps can handle a Hydroboost conversion, upgrading to a pump specifically designed for it (like a modified Saginaw P-series) provides better performance.

What I do know for sure, the pressure relief valve on all Saginaw steering pumps are interchangeable. The pressure hose connection maybe different. Use the relief valve from the original hydro-boost system. This will assure proper pressure.

Smaller drive pulley will spin the pump faster, more flow. If you have a higher revving engine, the smaller pulley will over speed the pump, if you have the higher RPM shift points. So this, will not be good.

 

[73 cheySuper]

Okay, I took a quick look at both control valves and didn't notice a difference, but I'd imagine it'd be very slight. I'll take a better look tomorrow. Thanx for that, that makes it simple.

 

[73 cheySuper]

Here's a snapshot of the 2 pressure valves, the one on the right is the standard, the left is the hydroboost version. Indeed different......I'll be just swapping these valves and my reservoir and call it a day.

 

[ss454elco]

I installed aftermarket hydraboost on my 84 K10 after an engine swap didn't provide enough vacuum. At first I pulled the reservoir and added a second fitting because I didn't like the idea of 'T' ing the return line. After reading about people burning up regular pumps I bought one for hydraboost. Glad I did. I only have about 2k miles on it since resto completed but brakes are awesome and no issues (yet). Regular pump should be ok if you change the piston and spring in pressure line. I just didn't want to take a chance. Do it right once and be done with it, IMO.