Clean GM Express Van Evaporator, Filter Install?

peteco · 05-08-2019, 07:22 PM

Has anyone attempted to clean the evaporator coil on their GM Express van? Also, I see there is a cabin air filter retrofit kit for GM trucks, and wonder if it would work on their vans.

After seeing the performance improvement of cleaning my house AC coils I thought it would help an older (2006) van's AC performance.

booster · 05-08-2019, 07:33 PM

Quote:

Originally Posted by peteco

Has anyone attempted to clean the evaporator coil on their GM Express van? Also, I see there is a cabin air filter retrofit kit for GM trucks, and wonder if it would work on their vans.

After seeing the performance improvement of cleaning my house AC coils I thought it would help an older (2006) van's AC performance.

I would have to look at the factory service manual (2007 which should be same) to see how much dash you have to take apart to get to the coil on both sides. Sometimes you have remove the entire dash, like I did on my wife's Tracer to replace the heater core. It may also be possible to find a spot where you could drill small hole in the ductwork and use compressed air to get the dirt out of the coil and hopefully out somewhere else.

peteco · 05-09-2019, 02:59 AM

Quote:

Originally Posted by booster

I would have to look at the factory service manual (2007 which should be same) to see how much dash you have to take apart to get to the coil on both sides.

I don't know why I didn't look at my 2006 manual, so thanks for mentioning it. The first thing I did was remove the resistor block. I could see the evaporator, and the plenum had a lot of leaves in it. I spent about 20 minutes vacuuming with a small hose, which didn't work very well, and using long tweezers to pull the leaves out. I then noticed the fan housing was close-by. It is very easy to remove the fan and gives much better access to the evaporator and plenum. It was much easier to clean out the leaves from the fan housing opening with a vacuum. The debris in the picture is only about half the amount that was in the plenum.

I then sprayed evaporator cleaner on the coils. After a few minutes I brushed the coils with a toothbrush and sprayed the cleaner off with a water nozzle. The bottom of the evaporator was still dirty so I sprayed cleaner on it and cleaned it as before.

There was some dirt buildup on the squirrel cage fan which my wife cleaned off.

I noticed some sort of grease was on the fan housing, which I assume was to help seal the fan housing to the casing. I cleaned it off and applied some Syl-glide grease to help seal it. I do not know why they did not use a foam rubber gasket to seal here.

I do not see a way to easily install a filter.

The AC seems to cool better with better airflow. As easy as this job is, I will check it next year to see how much debris buildup occurs.

rowiebowie · 05-09-2019, 03:08 AM

Quote:

Originally Posted by peteco

I don't know why I didn't look at my 2006 manual, so thanks for mentioning it. The first thing I did was remove the resistor block. I could see the evaporator, and the plenum had a lot of leaves in it. I spent about 20 minutes vacuuming with a small hose, which didn't work very well, and using long tweezers to pull the leaves out. I then noticed the fan housing was close-by. It is very easy to remove the fan and gives much better access to the evaporator and plenum. It was much easier to clean out the leaves from the fan housing opening with a vacuum. The debris in the picture is only about half the amount that was in the plenum.

I then sprayed evaporator cleaner on the coils. After a few minutes I brushed the coils with a toothbrush and sprayed the cleaner off with a water nozzle. The bottom of the evaporator was still dirty so I sprayed cleaner on it and cleaned it as before.

There was some dirt buildup on the squirrel cage fan which my wife cleaned off.

I noticed some sort of grease was on the fan housing, which I assume was to help seal the fan housing to the casing. I cleaned it off and applied some Syl-glide grease to help seal it. I do not know why they did not use a foam rubber gasket to seal here.

I do not see a way to easily install a filter.

The AC seems to cool better with better airflow. As easy as this job is, I will check it next year to see how much debris buildup occurs.

I can see by your pictures nothing changed from your model to my '2011. I heard some leaves in my blower this Spring and would like to check mine for debris as well.

So all I have to do is unplug the fan motor power wire and remove a few bolts on the fan housing?
.

peteco · 05-09-2019, 03:23 AM

Quote:

Originally Posted by rowiebowie

I can see by your pictures nothing changed from your model to my '2011. I heard some leaves in my blower this Spring and would like to check mine for debris as well.

So all I have to do is unplug the fan motor power wire and remove a few bolts on the fan housing?
.

3 small screws on the fan housing and 2 on the resistor block: 5.5-mm or 7/32-in socket. I suggest you remove both.

rowiebowie · 05-09-2019, 03:58 AM

Quote:

Originally Posted by peteco

3 small screws on the fan housing and 2 on the resistor block: 5.5-mm or 7/32-in socket. I suggest you remove both.

Thanks. I'm handy enough, but would not have attempted cleaning in there had you not posted.

.

booster · 05-09-2019, 04:13 AM

Great information, petco, it will go in the memory banks in case needed later. I think we tend to stay much cleaner in the air inlet area than most because the van doesn't sit outside unless we are traveling. Seems to make a big difference in a lot of things like this.

It will be interesting to see if you get better cooling now. We have found the AC to be plenty strong in the front are while driving, even in the 100-105* heat we hit on our last trip, along with full sun. Hardly ever took it off low speed. We always run in recirc mode though (max air setting on the knob which really helps, especially with lowering humidity.

peteco · 05-09-2019, 04:18 AM

Quote:

Originally Posted by booster

Great information, petco, it will go in the memory banks in case needed later. I think we tend to stay much cleaner in the air inlet area than most because the van doesn't sit outside unless we are traveling. Seems to make a big difference in a lot of things like this.

It will be interesting to see if you get better cooling now. We have found the AC to be plenty strong in the front are while driving, even in the 100-105* heat we hit on our last trip, along with full sun. Hardly ever took it off low speed. We always run in recirc mode though (max air setting on the knob which really helps, especially with lowering humidity.

It is so easy to check by removing the resistor block I suggest you just do it. I didn't mention it but there was some fine debris at the bottom that was holding moisture, which could promote corrosion or mold. Also, dust on the evaporator could affect efficiency, though it sounds like yours is working well.

rowiebowie · 05-09-2019, 04:28 AM

I just detailed my engine bay Monday, so no reason the fan compartment should not be as clean on the inside as on the outside.

peteco · 05-09-2019, 04:31 AM

Forgot to mention, to access the blower motor housing you need to remove the coolant overflow tank hold-down bolt and move the tank to the side.

rowiebowie · 05-09-2019, 04:35 AM

Quote:

Originally Posted by peteco

Forgot to mention, to access the blower motor housing you need to remove the coolant overflow tank hold-down bolt and move the tank to the side.

Thanks Pete.

Roadtreker357 · 05-18-2019, 07:04 PM

Thanks for posting the procedure to clean out the evaporator area. Had some time to remove the resistor and fan today. There were some leaves laying at the base of the evaporator area. Was pretty easy to vacuum them up through the fan opening.

I had some 3/4" tubing, cut slits in a piece of cardboard to insert the tubing through. Used a shop vac with the cardboard over the hose opening. Leaves stuck to the hose opening, just had to remove them and vacuum again and again.

Tom 07C210P

JohnnyFry · 05-19-2019, 04:51 PM

I got some noise when running the A/C fan so I removed the blower motor (easy: 3 screws and an electrical plug) and found a bunch of leaves up against the evaporator coil and in the enclosure. I used a shop vac, as well as reaching into the opening, to clean things out. Immediately increased air delivered and eliminated the noise. It looks like another one of those yearly spring jobs to put on the list!

booster · 05-19-2019, 05:09 PM

Quote:

Originally Posted by JohnnyFry

I got some noise when running the A/C fan so I removed the blower motor (easy: 3 screws and an electrical plug) and found a bunch of leaves up against the evaporator coil and in the enclosure. I used a shop vac, as well as reaching into the opening, to clean things out. Immediately increased air delivered and eliminated the noise. It looks like another one of those yearly spring jobs to put on the list!

It certainly does, especially if the van sits outside a lot. Leaves are really quite large, I wonder if some kind of screening somewhere may help. Most the time all I have ever seen in those areas of other vehicles are tree seeds and dirt. My old Buick actually has window screen type material on the inlet vents behind the hood (which we totally blocked with fuzz) so the inside is really quite clean for 23 years old.

Our van is nearly always inside except when traveling, so this may help explain why we have seemed to see better AC cooling in it than many others have reported for the Chevies.

SteveJ · 05-19-2019, 06:24 PM

Thanks for the how to and heads up on cleaning the evap coil. I didn't hit it with coil cleaner but did remove a bunch of crap with compressed air and a vac. Went for a short ride to give a grandbaby a thrill and it seemed to work better. But that could be my imagination, I've had no complaints. It's always done fine even in Texas August heat. And that's saying something.

Test conditions: 86* with a 65 dew point.

booster · 07-13-2019, 02:05 PM

A little late getting back to this, but on our last trip, I noticed water coming out from up by the front bumper when parked nose down, and looking under the hood it appears the water was from the AC housing and coming out around the flange.

I would assume this means plugged drain. Was the drain line accessible when you took out the fan motor and could get inside?

peteco · 07-13-2019, 02:45 PM

Quote:

Originally Posted by booster

A little late getting back to this, but on our last trip, I noticed water coming out from up by the front bumper when parked nose down, and looking under the hood it appears the water was from the AC housing and coming out around the flange.

I would assume this means plugged drain. Was the drain line accessible when you took out the fan motor and could get inside?

I sprayed a lot of water in when I cleaned and it flowed out readily, but I don't recall where the drain was. It should be easily accessible when you take the fan and resistor block out. It will be interesting to see how much debris you have with your vehicle spending most of its time indoors.

booster · 07-13-2019, 04:39 PM

Quote:

Originally Posted by peteco

I sprayed a lot of water in when I cleaned and it flowed out readily, but I don't recall where the drain was. It should be easily accessible when you take the fan and resistor block out. It will be interesting to see how much debris you have with your vehicle spending most of its time indoors.

Thanks Pete, it will be interesting. My guess is, if it is plugged up, it might be the ugly yellow pollen from the red pines in Custer State Park. Our first trip there we hit pollen season and it was so thick it was in drifts on the ground and all over the van. We still find it to this day sometimes. I don't recall ever being in much else, but there always are some tree seeds and if they are the right size it only takes a couple.

booster · 07-13-2019, 09:52 PM

Turns out it was all a false alarm. There is no drain to the ground, at least on our 07 van. There is just a hole in lowest part of the underhood housing just about in line with resistor pack, next to the screw that is second from the left along the front edge. I didn't even feel it when I went looking initially and didn't find it until I poured water in the housing with the fan out and watched where it came out. It dumps right on the wheel well and then just runs down and out on the wheelwell. If it is nose down it looks like it would hit the frame and run to the front where we saw it coming out. There is a also a second fairly low spot right under the fan cage that will hold water if it gets there, but it is higher than the condenser area. If water is sitting there is slowly dribbles out along the cover edge. Water there would not be from the evaporator, though.

I found one small leaf and about 5 long red pine needles in the housing and the evaporator looked nice and clean.

peteco · 04-09-2020, 03:09 AM

Heard leaves flapping in the fan, so it was time to clean the evaporator housing again. I removed the resistor block as before and started removing leaves with my long tweezers and a small flexible tube hooked to my vacuum. There was a lot more leaves than the last time. After a while I got tired and stopped to think a little bit. Then it hit me: turn on the fan to blow the leaves out the resistor block opening. This worked OK, but I then added another twist: I used a compressor blowgun to "stir up" the leaves and debris while the fan was running. This worked even better at blowing all (hopefully) of the leaves and debris out. The picture shows the blowgun in the resistor block opening.

I was puzzled why I had so many leaves in the housing. I had the windshield replaced in December. So I looked and noticed the windshield bottom frame was lifted off the windshield more than I recall on the original windshield. So leaves were slipping into the air intake through this gap. I will contact the windshield installer to get them to seal the gap.

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