Saturday, October 29, 2011

Power Steering Pump Service for Buick Rendezvous.

Disclaimer: I have no control over your work, and any work on vehicles is potentially dangerous for you, your passengers or the public. Improper service techniques can result in injury, death or property damage. The methods given may or may not be typical or accepted service procedure. You must use your own judgement before attempting any repairs on your vehicle or those of others. Do these and any other repairs at your own risk...

Another thing while I'm at it. Power steering noise is usually caused by a worn pump, not a defective rack. Extra effort to steer could or could not be the pump or rack getting ready to check out. A failing power steering pump will likely have leaks as well. A little noise first thing on a cold morning isn't a huge deal. However, once you warm up your ride, the noise should go away and not be heard over the engine. If you heard a whine, growl or groan from the front of the engine even when you aren't turning the wheel, suspect the pump is on its way out.

For nearly three weeks, I've put up with noise from the front of my Rendezvous and since the odometer is ready to hit 150,000 miles in the next month, it was time to replace the power steering pump. On the 3.4 liters, which GM put in most of their cars and minivans in the early 2000's this pump lives at the front of the engine (right side) on the very top. There only three bolts, two hoses and a belt to deal with. The only thing that should give you issues is the low pressure hose that connects to the reservoir. You will need to suck the fluid out of same with a poultry baster or suction gun and use a long handled 3/8 inch socket wrench or breaker bar to release the tensioner to remove the belt. You could use a belt tensioner tool, but the ones from Auto Zone don't work very well on this one unless you add an adapter from your tool box. Take the belt all the way off and set it aside. You'll need a 10mm, 13mm, and a 15mm socket as well as a pair of needle nose pliers, socket wrench handle, power steering pump removal tool (rent this) and 15mm open end wrench.

Before you do anything else, go ahead and check out the two idler pulleys. Grab them, spin them or just take them off and check the bearings for noise or roughness. If they make any noise, go ahead and replace them now. The reason being is that they'll cause the bearings on your new pump, your alternator, water pump, to fail because of play in the belt and heat transfer. These pulley's are about $17.00, while an alternator is about $200 and an A/C compressor is nearly $800. A power steering pump is about $40.00 at Auto Zone and a little more everywhere else, but I digress.

Remove the belt and cover from the front of the engine. Take your wrench and unscrew the pressure line from the back of the pump and your pliers to back off the clamp from the line on the reservoir. There are three 13mm screws holding the pump to the engine and you'll have to get to them through the pulley. Just unscrew them and be careful not to drop them. Take a flat head screwdriver and carefully pry the hose off the spud on the back of the reservoir as you remove the pump. That reservoir is plastic and if you break it, you'll be replacing it. You can make a 1/4 slit in the hose with a razor blade to make this easier, but no more or you'll be replacing the line. Just take your time, because there isn't a whole lot of room to work. Once you get the pump out, make sure all the fluid is out.

There are two clips holding the plastic reservoir to the metal pump. Pry on the tabs with screwdriver and use a small hammer to tap them off. Now you can pull off the reservoir and set it aside. The pulley will also need to come off, so get your tool you rented and follow the directions on the box. You can use this same tool to install the pulley on your new pump flush with the shaft. As always, don't break it as this is also plastic. Use a new O ring on the reservoir and use the clips to fasten it to the new pump. These clips are specific to each side, so don't mix them up. Tap them back on with a hammer until the tabs click in.

Put the pump back in, working the low pressure hose on the reservoir with a straight blade screwdriver. The slit will help the hose fit back over the spud. Be careful of the sensor and wire harness below the pump as you could break them as you manhandle the pump back in. Once you have the hose on, go ahead and slide the clamp back down and start the high pressure line (install a new O ring on the line first) but don't tighten it yet. Start the three screws that hold the pump in by hand and a deep well socket and once you're satisfied they're threaded in right, tighten them up with a 1/4 inch socket wrench. Then go ahead and tighten the pressure line snugly. Reinstall the belt (check to make sure the belt is in good condition) and fill the reservoir with clean power steering fluid. Start the car and move the steering wheel back and forth about 10 or 15 times. Check the reservoir to make sure the level is still full and keep moving the wheel back and forth until the noise from the system goes away. This is called "bleeding" the system; getting rid of the air in same. Be patient, because there will be more effort to turn the wheel and it could take a half hour or more. You could speed this up by putting the front end on jack stands, but this also requires some effort. Just keep turning the wheels back and forth and once it smooths out take the car for a drive and makes some turns with it. The noise should be much diminished if not gone altogether once all the air is out of the system. Maranatha!

1 comment:

Walter Grace said...

If you want to flush this out, just leave the pressure hose off and hook another clear hose to same with a clamp. Put the other end into a gallon jug. Start the engine and slowly pour fresh fluid in the reservoir until the fluid runs clean. Shut off the engine, reconnect the pressure line and you're done.