Replace Your Chevy or GM Power Steering Pump
Replace the PS Pump on a V8 Small-Block Chevy
If you have determined that your power steering pump is bad, here are step-by-step instructions for replacing it. These illustrations are for a 2000 Chevy Suburban with 4-wheel drive, but the same basic procedure applies to most front-mounted pumps on a V-8 engine.
First, make sure you have the correct parts. You will need:
- a pump
- hoses (possibly)
- a new pulley (possibly)
- a new serpentine belt (possibly)
Compare the new parts to the old before taking everything apart. In my case, the pump did not come with a new reservoir, so it didn't look like the old installed pump at first glance. Carefully check for hose ports and mounting holes in the same positions as the old unit. If they match, you should have the correct pump.
Line up your tools. To do this job you will need:
- metric sockets
- a ratchet
- Loctite #242 threadlocker
- a large adjustable wrench
- (possibly) a serpentine belt removal tool and hammer
- a body/trim retainer tool
- a small flat-blade screwdriver
- hose-clamp pliers
- a flare nut wrench
- and a large bottle (over 30 ounces) of the manufacturer's recommended PS fluid.
You've got the right parts and tools, so now it's time to get dirty.
Removing the Old Pump: Step by Step
1. Disconnect the negative (ground) connection at the battery. But if you have an anti-theft system for your radio or other electronics, make sure you know the reset codes or disable the system before disconnecting the battery. The GM Theftlock system disables the radio/CD/tape console when the battery is disconnected, and will ONLY reset with the passcode. Enter the wrong passcode a few times, and it locks down so that only the dealer can reset it.
2. Remove the upper radiator shroud. It's attached with two 10-mm bolts and four body/trim panel fasteners. The panel fasteners work like a drywall anchor. They consist of two pieces, a flange with a hollow shaft and a solid shaft with a button on top. To remove one, lift the button with a trim tool or screwdriver which extracts the inner shaft from the hollow shaft. This reduces the diameter of the larger hollow shaft and allows the two-piece assembly to pull out of the hole. Don't try to pry the large flange without first lifting the button or you will damage the fastener.
3. Loosen the hose clamp for the air intake tube, separate the tube from the intake manifold, and carefully move the tube and resonator aside.
4. Remove the fan. You may need to strike the wrench with a hammer to break loose the large nut. If the serpentine belt does not hold the fan pulley from turning, try pressing on the belt while striking the wrench with a hammer. If it requires so much force that you turn the crankshaft, you will need to remove the serpentine belt (see steps 6-7) and hold the pulley with a strap wrench. Holding the fan blades won't work. You may damage the blades or the viscous clutch between the fan and the nut.
5. Remove the lower radiator shroud. On the Suburban, it just lifts out, having been held in place by the upper shroud and a flange at the bottom that slides into the radiator support (no bottom fasteners).
6. Make sure you know the routing of the serpentine belt. There should be a diagram in the engine compartment, but if not, take a picture or draw a diagram. It's easy to forget the route by the time you're ready to reinstall it.
7. Remove the serpentine belt. Using a 15mm socket, "tighten" the bolt on the belt tensioner to swing it down. Remove the belt from at least one pulley and slowly release the spring tension on the belt tensioner. Move the belt away from the PS pump.
New and Old Pulleys
8. Using a power steering pulley removal tool, remove the PS pulley. I didn't need to do this for this job, because the pump shaft was broken, and I could just pull the pulley, with the broken shaft attached, out of the pump. Since I don't have pictures of using the tool, I'll attempt to explain the process (you can also see it in the first video below). The special puller consists of a split-ring flanged adapter, a ring, a puller bolt, and a puller nut with a flange. Slide the smooth end of the puller bolt into the hole in the pump shaft, and run the nut down to the pulley. Then place the two-piece adapter into the pulley groove and over the puller nut flange. Slip the ring over the two-piece adapter to keep it together. Use one wrench to hold the flanged nut, and another to turn the hex head of the puller bolt. As you tighten the bolt, the pulley will slide off the shaft. If you're lucky. A ten-year-old pump will have become very attached to its mating pulley and will only very reluctantly part with it. That's why a new pulley is mentioned in the parts list above. Don't use a regular two- or three-jaw puller, as it will distort the pulley and cause it to wobble on the new pump. If you can get the pulley off without damage, you can re-use it, as long as it slides tight on the new pump shaft. For $15 or so, I opted for a new pulley.
9. Jack the vehicle, using factory-recommended procedures, and support it with jack stands. Do not work under a vehicle supported only by a jack. In the case of the Suburban, raising the vehicle was not necessary to gain access to the power steering pump.
Get to the Pump
10. Working underneath the vehicle, remove the 5 bolts (15 mm) holding the plastic stone shield.
11. Remove the hose guard: Using a wrench (15mm), remove the single bolt holding the hose guard to the pump, remove the hose guard, and set it aside.
12. Place a drain pan beneath the pump to catch any fluid, and then disconnect the pressure line from the pump (see first photo below) using a flare nut wrench. If you're careful and the nut is not too tight, you can use a regular wrench, but make sure you don't damage the nut. If you are re-using the hose, cap the line to prevent dirt from entering.
13. Disconnect the EVO valve electrical connector. You may need to use a small screwdriver to lift the locking tab in order to separate the connector. You may find it easier to access this from above.
14. Using hose-clamp pliers, disconnect the return line from the pump. If you're not easily frustrated, you can use regular pliers, but hose-clamp pliers make this a lot easier.
Get the Alternator/PS Bracket Out of the Way
15. Working from above, remove the three bolts (15 mm) attaching the front of the pump to the alternator/PS bracket (marked with blue circles, see first photo below).
16. Remove the two bolts (10 mm) attaching the electrical splice box to the alternator/PS bracket (see second photo below).
17. Remove the four bolts (15 mm) attaching the alternator/PS bracket to the engine (marked with red circles in first photo below). Move the bracket out of the way, being careful not to stress the alternator wiring harness.
18. Remove the single 15 mm bolt attaching the PS pump bracket to the engine behind the pump. This bolt is located just above the EVO valve electrical connector.
19. Work the pump out over the wiring harness and down, to remove it from the engine compartment from below. Removing the splice block bracket screws should give you enough slack to move the wires out of the way.
Disassembling the Old Pump And Cleaning Parts for Re-Use
Take Apart the Old Pump
Take the pump to your workbench for disassembly. It will probably be a little messy because there will be some fluid in the reservoir and fittings. Have some rags or paper towels handy.
First remove the two bracket nuts and the bracket, then remove the two bracket studs. They are different on this pump. One has a slightly taller shoulder. Loosely assemble the studs, bracket and nuts to keep them in the correct holes (the bracket can only mount one way), or make a note of which bolt goes where.
Remove the EVO Valve
Carefully remove the pressure line fitting or EVO valve, if you have variable-assist steering. Behind the fitting/EVO valve is the pump's pressure valve, and behind that is a spring (see photos below). Don't let the pressure valve and spring fly out.
Remove and (if Necessary) Clean the Reservoir
Pull the pump body from the reservoir. Do not pry around the fitting or mounting bolt holes. Because the reservoir is made of thin metal, you will bend it, making it impossible to get a good seal to the new pump. You also cannot pry around the pump body because you will distort the sealing surfaces for the large o-ring around the new pump. The best way to get the pump and reservoir separated is to hold the pump shaft in a wood vice and pull on the reservoir. You can also hold the reservoir in the vice and use a thin brass punch in the bottom of the bolt holes to gently loosen the pump from the reservoir. You can also buy a pump/reservoir assembly or a separate reservoir if you need one.
Wipe the interior of the reservoir clean and examine it, inside and out, for rust. Scale rust on the outside is okay; just wire-brush it off and re-paint with a rust-preventative. Make sure you tape it off so you don't get paint overspray inside the fluid tank. If you have rust on the sealing surfaces around the bolt holes, fitting hole, or pump body seal, or on the inside surfaces of the reservoir, you need a new reservoir. If you have deep rust that will not wire brush off or has perforated or nearly perforated the metal, you need a new reservoir. You don't want to do this again next year, do you? In all likelihood, the new or remanufactured pump will last several years, so you want to make sure the reservoir will last as long.
Assemble the New Pump
Your new or remanufactured pump should have come with a set of gaskets. Mine came with two sets of pump-to-reservoir seals, plus pressure-fitting seals, and it had the large body o-ring factory installed (see pictures below).
If you had an EVO valve on your old pump, you'll need to install it on the new pump. My remanufactured pump came with a new pressure valve and a straight fitting. I had to remove the straight fitting and replace it with the EVO from my old pump.
Installing and Testing the New Power Steering Pump
Install the Pump
Place the pump in its approximate position. Make sure the wiring harness is below and behind the pump body.
Apply Loctite Threadlocker Blue #242 to the threads of all mounting bolts before assembly.
Position the alternator/PS bracket and run the four bolts into the engine block, finger snug.
Position the pump and run the three bolts through the bracket and into the pump body, finger snug. Note there are three identical bolts and one slightly shorter with a rounded tip. The shorter bolt is for the rear bracket.
Place the hose bracket around the PS hoses, slide the bracket into position on the pump body, and run the bolt through the bracket and into the pump body, finger snug. Make sure the bracket confines the hoses away from the steering shaft.
Run the rear pump mounting bolt through the bracket in into the engine block, finger snug.
Attach the pressure hose to the EVO valve fitting and tighten to specifications.
Tighten to specification the four alternator/PS bracket bolts, the three front pump mount bolts, the rear pump mount bolt, and the hose bracket bolt.
Re-attach the electrical splice box bracket to the alternator/PS bracket and tighten to specs.
Install a New Filter
A new filter is needed to preserve your warranty.
If you are installing a NEW in-line filter in a system that did not have one, find a convenient place for it along the route of the RETURN hose. Cut the hose where the filter will be installed. Depending upon the position and routing of the return hose, you may need to make two cuts to shorten the hose by about one inch less than the length of the filter. In other words, if the filter is four inches long, you may need to remove three inches from the hose.
Insert the filter in the line, paying attention to the fluid flow. The filter should be marked with an arrow, or with "IN" and "OUT," or maybe just 'IN'. The "OUT" end should be closest to the pump, since you are installing the filter in the RETURN line. Do not attempt to install the filter on a pressure line!
Attach the filter with hose clamps. The filter I bought came with stainless steel screw clamps, but they were about 1 mm too small. If I opened up the clamps as far as possible without disengaging the screw, they were too small to slip over the barb on the filter. It took longer to get these clamps on than to install the pump! Just a head's up in case you buy the same brand: you may want to spend an additional dollar and get a couple of larger clamps.
Attach the return line to the pump fitting and secure with a hose clamp.
Install the Pump Pulley
Install the pump pulley with a pulley installation tool. If you bought a puller, they usually come with an installation tool, but a bolt and washers with work just as well. The pulley I purchased came lubed with white grease, but if you are re-installing your old pulley or a new, unlubed pulley, make sure the bore hole is clean and lubed before attempting to press it on.
Installation is as simple as starting the bolt with a number of washers and tightening. Make sure the pulley is squarely aligned to the shaft. You can't press it on without damage if it starts crooked. Hold the pulley with one hand, to keep it from turning, while tightening it with the other. As you press the pulley into place, you will need to back off the bolt and add more washers every 1/2 inch or so. I used one, then two, then three open-end wrenches to gain the extra depth, instead of removing the bolt and adding washers.
At some point, the pulley may begin to offer so much resistance that you can't hold the pulley with one hand. At this point stop and install the serpentine belt, which will hold the pulley from turning, then continue pressing the pulley until the face of the bore hole is even with the end of the pump shaft. This should align the pump pulley with the belt track. Check this as you are pressing the pulley. You don't want to go too far in.
Final Reassembly and You're Nearly Finished
Carefully replace the lower radiator shroud into the radiator mounting crossmember. Make sure it is securely seated.
Replace the fan / fan clutch assembly and tighten to specifications.
Reinstall the serpentine belt. First inspect it for wear. Small cracks across the ribs are okay, but long sections of missing ribs, two or more adjacent missing rib sections over 1/2 inch long, or cracks (lengthwise down the belt) are not; these kinds of wear will allow the belt to jump off the pulleys. After installing the belt, check the wear indicator on the belt tensioner. There are two or three marks on the base and one indicator line on the movable arm. With the belt in place, the indicator should rest between the outer marks on the base. Replace if necessary.
Replace the upper radiator shroud and attach with four panel fasteners and two bolts.
Reseat the upper radiator hose into its hold-down clamps and clip shut.
Replace the air intake tube and tighten the clamp at the intake manifold.
Reattach the battery ground cable.
Add Fluid, Bleed, and Check for Leaks
Fill the reservoir with new clean fluid, of a type approved by the vehicle manufacturer, and replace the fill cap. With the engine disabled, crank the starter for a couple of seconds. Check the fluid level and add more if necessary. Repeat this at least three times or until you no longer need to add fluid.
If you have not already jacked up the front of the vehicle and supported it with stands, do so now. Don't forget to block the wheels.
Re-enable the engine and start it. Let it run for a few seconds, turn it off, and check the fluid level again. Add fluid if necessary and repeat until you no longer need to add any.
Start the engine and move the wheels full left and full right three times, but don't hold the steering wheel at either full-lock position. The squealing you hear when the steering wheel is turned full left or right is the pressure valve venting, and this puts strain on the pump. Stop the engine and check the fluid. Add as necessary. Repeat until you no longer need to add fluid. Don't overfill. You should be using the "cold" mark on the dipstick.
Start and let the engine run for a few minutes while checking for leaks. If any fitting or hose is leaking, turn off the engine and tighten the fitting or clamp. If the pump or reservoir is leaking, you will need to pull the pump and find the source of the leak. I wouldn't want to be you.
Assuming you have no leaks—and you shouldn't if you carefully assembled the pump and hoses—you are nearly finished, and congratulations are in order. Remove the jack stands, lower the vehicle to the ground, remove the wheel chocks, and carefully test-drive your once-again easy-to-steer vehicle.