ORD Spec Hydraulic Assist System for GM Trucks
Offroad Design has put together the best hydraulic assist system on the market! In cooperation with PSC, the best name in steering, we've built a system that you won't find anywhere else.
Included is a 100% new high pressure high flow power steering pump and filtered remote reservoir system. The pump will bolt directly in place of the stock truck power steering pump, the reservoir includes a couple different ways to mount it but there is some work involved in mounting the reservoir as there are many ways to do it on many different engines.
We use a #12 feed into the pump and #8 return line coming back from the steering box, these bigger lines help free up the system and let the pump flow more. The higher flow means the system reacts faster and leads to faster steering. Note that the bigger feed and return are only available on the '80 and newer o-ring style parts. If you have a '77-79 truck, you can simply order the '80 and newer parts and they'll swap right on other than a new pressure hose from a parts store. If you have a '76 and older GM truck, you'll need the pressure hose as well as a way to adapt the splines at the input of the box. Either a later rag joint assembly or an aftermarket steering shaft (like Borgeson).
The "standard" in cylinders is 8" of throw, but this doesn't allow enough travel to get all the way to lock. You can destroke a longer cylinder, but they get hard to fit and mount. So we have our own scratch built 8-3/4" travel cylinders that hit the stops just right, the extra steering angle makes a big difference!
Also included is a 100% brand new (casting and all) PSC upgraded steering gear. Bigger bearings, beefed up casting, and internally ported for the best flow to keep the steering quick. You can't get a better steering gear box!
Of course all of the hoses and fitting are included to plumb everything together and mounting tabs are included with the cylinder.
Below are some examples of how we have our trucks setup. Of course if you have a GM axle it will just be mirrored:
The main goal when mounting the cylinder is having it push as straight as possible. If it pushes at an angle it can bend the tie rod.
<h3 class="acc-header" style="cursor: pointer;" data-id="01">Vacuum vs hydroboost brakes</h3>
<div id="acc-01" style="display: none;">
<h4>Simply choose whether your NP203 range box came from a GM, Dodge or Ford truck.</h4>
<p>Simply select which option for your truck's power brakes. Vacuum brakes have a big vacuum hose running to the brake booster, hydroboost brakes get their power assist from the power steering system.
<br><br>The reservoir has a secondary return, with vacuum systems we send a plug for that and with hydroboost we send a fitting for the hydroboost return. So it's just a minor fitting change if you change your mind down the road.</p>
<h3 class="acc-header" style="cursor: pointer;" data-id="02">Pump and Reservoir</h3>
<div id="acc-02" style="display: none;">
<p>Select the pump/reservoir generation for the year of your truck, the only exception is for '79 and older GM trucks swapping on an '80 and newer steering box see steering box year for more info</p>
<h3 class="acc-header" style="cursor: pointer;" data-id="03">Cylinder Size</h3>
<div id="acc-03" style="display: none;">
<p>A bigger cylinder makes more steering power, but takes the pump longer to fill it with fluid. The 1-3/4" cylinder gives more power offroad but will be slower when you're trying to spin the steering wheel quickly still streetable. The 1-1/2" cylinder is targeted for more dual purpose use, it still roughly doubles the steering power but is more street friendly.</p>
<h3 class="acc-header" style="cursor: pointer;" data-id="04">Steering Gear Box Year</h3>
<div id="acc-04" style="display: none;">
<p>Simply pick the generation that your truck falls into.
<br><br>The exception would be in swapping a newer steering gear box onto an older truck. The larger feed and return fittings free up flow and are a good idea where possible, these are only available on the '80 and newer boxes. It is possible to use an '80-87 box on a '79 and older Chevy truck by swapping the rag joint or universal joint to the '80+ style. This is common with newer drivetrain swaps as well, with an '80+ engine it makes a lot of sense to use the '80+ steering box so that the hoses match up and don't need to be custom.</p>
|PSC Instructions||286.9 KB||Download|
|How to bleed system||86.2 KB||Download|
|Installing Fittings||316 KB||Download|
|Reservoir mounting tips||1.2 MB||Download|
|Reservoir Tips||351.6 KB||Download|
|Cylinder tips||263.1 KB||Download|
|PSC assist routing||286.9 KB||Download|