How To: Clean out sunroof drains
 

This is for anybody who has a sunroof in their Blazer and has either had mysteriously wet floors or heard water sloshing around in the headliner while driving. If you had any of those problems, then chances are your sunroof drains are clogged. While I did not have this problem, I have a buddy who did on his 2003 ZR2 Blazer so I searched for a solution to fix it and could not find one. I couldn't even find anything that gave me the exit locations for the drains, everything I found told me I had to either remove the sunroof or remove the headliner in order to gain access to clean the drains. I knew there had to be an easier way....and here it is.

First lets locate where the drain hoses actually drain out of. There is a drain in each corner of the sunroof (4 total), 2 that drain the front and 2 that drain the rear. If you open up the front doors, you will see a small rubber hose sticking out from the frame just above the top hinge, those are the drain hoses for the front drains (pictured below)

https://blazerforum.com/forum/attach...ine=1368632770

The rear drains are located underneath the truck between the rear tire and the rear bumper about 1' in from the rear bumper. (pictured below)

https://blazerforum.com/forum/attach...ine=1368632770

Now that we have located them, we need a way to clean them out. I used an air compressor and some blower attachments.

https://blazerforum.com/forum/attach...ine=1368632770

Now for the process of cleaning out the hoses. Make sure the sunroof is open and inspect for dirt, leaves, or whatever else might be blocking the drain holes around the sunroof. I took the long curved blower attachment and inserted it into the drain hose in the door....
https://blazerforum.com/forum/attach...ine=1368632770

I slowly pressed down on the lever and let the air run out and through the hose. You can hear the air coming from the hole in the sunroof. Go slow because if your hose was completely clogged and had water sitting in it, it would probably blow out and fall into your truck through the open sunroof. Repeat the process for both front drain hoses.

For the rears, you can take a long screwdriver and stick it into the rear hoses to unclog whatever crap is stuck at the bottom preventing the water from draining. I say to use a screwdriver first because if they are clogged up and holding water, you might want to get all or as much water out of them as possible before blowing air up there and spraying it all over the place. I wasn't able to do this to the front because of the tight area and angle of the hose. Once you try to free up any clogs with the screwdriver, move onto the blower attachment and go to town. Repeat for both sides.

I did this to my buddy's 2003 ZR2 Blazer and my 2001 ZR2 Blazer. Both are obviously 2 doors but im assuming its the same for 2 or 4 door (I have not confirmed this). I also wanted to state that I did not damage anything in the process while using the air compressor but try this at your own risk. I don't want to say it wont damage anything and have people blame me if they use too much pressure and blow something out. Start out slow and make sure you can hear the air coming out of the sunroof drains.

How is that a good idea to have a drain tube spilling out onto the door hinge? You'd think someone could have thought of something better.