My CHECK ENGINE SOON light came on while driving into the office this morning. That made what was already going to be awful morning even better.

This light came on for me a few years back and at the time it had to do with a loose gas cap. That doesn’t seem to be the case this time around. On the way home I stopped at Autozone and had one of the techs read the ODB II computer for me. Turned up an error code of P0440, which according to his reader had to do with the Purge Valve that sits on top of the manifold.

I also checked the Avalanche forum to see what I could find, but so far only found one post about 440 being a generic code having to do with the emissions evaporative system that can include any one of these issues:

• Missing Fuel Cap
• Defective or damaged Fuel Cap
• Distorted or damaged Fuel Tank filler neck
• Torn or punctured Evaporative System hose(s)
• Defective Fuel Tank Sending Unit gasket or seal
• Split or damaged Carbon Canister
• Defective Evaporative Vent Valve and/or Evaporative Purge Valve
• Defective or damaged Fuel Tank
• Defective Fuel Tank Pressure Sensor

I think I’m going to start with the Purge Valve as a starting point, only because that’s what the AZ tech’s device said specifically.

The forum had a diagram of the part that helped me locate where under the manifold cover it’s located. (#3 in the picture below). So I went under the hood tonight to see how difficult/easy it will be to replace. It’s not too bad actually – It’s close to the front with two lines connected to it, one for the vapor pipe and the other for the solenoid. GMpartsdirect.com has it available so I’ll order the part and see about replacing it.

Changing out the pads for the front disc brakes on the Pacifica is about half hour job. First thing to do is jack up the side you’re working on and secure it with proper jack stands. Once you remove the wheel you’ll be confronted with rotor and caliper assembly:

What I typically do next is release some pressure from the pistons by depressing the caliper. You can get a special tool to do this, but I find a C clamp does the job just fine. It’s rather difficult, if not impossible, to swing open the caliper housing without doing this.

Another view of the depressed caliper:

I next loosen the two bolts attached to the slide pins at the top and bottom of the caliper.

I tend to remove the top one completely and let the caliper swing open. I’ve seen folks remove only the bottom one and let it swing up. In my case I have to rest it on something so I just use another jack stand. Either way, the results are the same:

The pads are easily removed at this point. I also remove the pad retainer clips.

I then start the reverse process by first installing the new clips:

…and subsequently the new pads:

Be sure to use some grease at the contact points of the pads and the retainer clips. The grease reduces any noise and possible sticking.

Because the new pads will be thicker than their old, worn-out counterparts, you’ll probably need to depress the pistons a bit more so you have clearance to swing the caliper back into place. I usually just use one of the old pads here, placing it flush to the pistons, and depress them again with the C clamp.

Once those pistons are depressed all the way, swing the caliper back into place. Replace the top bolt that was removed, tightening it and the one at the bottom.

The new pads are now ready to go.

Took the truck into the dealer on Friday. All winter long I’ve been hearing a sort of grinding noise coming from somewhere underneath the truck (sort of sounds like the rear diff) and it’s progressively gotten worse and worse. The tech and I took it for a drive around the lot and he heard it right away, but said it was the driver’s side wheel hub. Ok, no prob… fix away.

I call them around 3:30pm because I haven’t heard anything back yet and the guy tells me, “We were just talking about you.” Whenever the dealer says that to you on the phone it can’t be good. He said the techs had the truck up on the lift and “heard noises coming from all over the place”.

The rear wheel backing plates, which seemingly don’t really do anything, were completely rotted away and were one source of noise. They need to be replaced. Another sort of rattling noise is coming from the rear wheels… this time it’s the left rear parking brake. The lining had seperated from the shoe. Replace that. Oh, and your pads are really low so they’ll need to be replaced and the rotors resurfaced. And finally… we come back to the rear differential. Needs an overhaul. Case and axle bearings were shot. The axle shafts definitely show wear, but an axle bearing repair kit can be installed to elliminate having to replace the axle – oh thanks. Heck, while it’s up on the lift you guys might as well flush the tranny for me and refill her with some new fluid.

Grand total: $2,309.16

Fun!

Last week I got into my truck and attempted to lower my window. As I did, I heard a loud noise and the window subsequently stopped moving. I took off the inside door panel later that night to take a look around and it turned out the wire that’s part of the window regulator just tore in two. I ordered a replacement regulator from car-stuff.com and it came this week. Removal and installation this evening went without a hitch. Once of my colleagues needs to do the same thing on his car so I thought I would help by documenting the process…

Driver side window regulator replacement on a 2002 Chevy Avalanche.

1. Remove the door panel. There’s a 7mm bolt that’s exposed just under the door handle and another one that’s behind the control switches. You’ll want to remove the triangle shaped trim to the right of the window as well as the trim cover behind the door lever. Disconnect the wires from the control switches and slowly lift the door panel. There’s another connection to the speaker you have to remove, and then also the door light bulb and wire located towards the bottom of the door.

2. Next you’ll need to remove the water deflector. I’ve done this a couple times so mine came off pretty easy, but make sure you don’t rip it because you’ll need to replace it. I removed the bolt that holds the door lever. It slides off and I just let it hang there. I did end up having to cut a slit through the plastic in order to get the deflector over the door lever.

3. At this point you’ll need to raise the window all the way up. If your wire has broken like mine it should be pretty easy to do. I secured the window with blue painter’s tape. Use a lot of it and you’ll get the same strength as duct tape, but without the residue.

4. Remove the wire harness that’s connected to the window motor.

5. Loosen the two bolts on the clamps that hold the window.

6. On the Avalanche, there are a total of six bolts that hold the window regulator in place. Remove all six.

6. Once the bolts are removed you should be able to jiggle the clamps loose, collapse the window regulator in on itself, and rotate it 90 degrees in order to be able get it out from inside the door.

The failed regulator:

The new regulator:

7. Now to install the new regulator simply do everything in reverse. Before I placed it inside the door I loosened the two bolts on the window clamps. After getting it in the door, I added all six bolts back in place, and once was happy with the way everything was situated, tightened them down. At this point I also reconnected the motor’s wire harness. The window clamps were just a few inches lower than I needed them to be so I temporarily reconnected the wire harnesses back to the control switches and raised the regulator up. This was also a quick way of testing to make sure the new motor and regulator were working properly.

8. Once raised, tighten the two bolts on the window clamps.

9. Remove the tape, and test the window.

10. Replace the water deflector. I used a weather-proof plastic tape to help the membrane stick back onto the door. You should double check exactly where your door panel will go back on to make sure no tape is revealed behind it.

11. Replace the door panel.

12. Celebrate the fact that you’ve got yourself a working window again.