DIY Lower windshield cowl/drains
07-12-2016, 11:20 PM
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2000 CLK430, 2012 BMW X5 3.5d
DIY Lower windshield cowl/drains
Learned this the hard way. Had an expansion valve replaced so I decided to remove the windshield cowl drain to gain full access to the expansion valve. Had an AC shop do the replacement with a new valve and drier but saved several hours of labor buy giving them full access. The upper assembly and wiper has to be removed. Info regarding this is available on this site. The problem is getting the entire lower assembly out. I learned the hard way and wrestled it out and this was a mistake. Once its out you CANNOT put it back in no matter how I tried. During removal I cracked it and chewed up the intake gasket. Was pretty stupid as the part is fairly expensive. Bought one on eBay for 32.00 vs 125 at the dealer. The plastic cannot be glued - its polypro and anything I tried just pealed off. There just isn't enough room to get it in properly. So here is what I did.
1. The firewall center is removable and this has to be taken out. I figured this out this morning when I started looking around. Figured MB had to engineer a way to remove it easily. Its a pain and lots has to come out but it will give you plenty of room. There are two bolts on either side - one just above the duovalve and the other near the brake booster There also is an ac line near this point and the bolt holding it should be removed to just slightly give you some access to the bolt and to move the ac line out of harms way.
2. Next - Disconnect the battery and open the wiring junction box which is next to the duovalve. Remove the two wiring harness connectors and a third long single connector. There also is a very small connector with a single wire. I wouldn't move things around to much because the wiring is fairly old and you don't want to break anything. The entire assembly needs to be gingerly moved off the firewall shield which is held by two clips which have a ziptie through them. The rubber grommet simply pulls up with the wire harness though it.
3. Pry off the tops of the two rivets that hold the asbestos shielding and remove it. Now remove the two bolts holding the firewall shield.
4. Gently pry off the brake booster vac line at the brake booster. This goes through the firewall shield. Pull it through.
5. Remove the vacuum line (white) going through the shield - it snaps at a connector.
6. Lift up on the shield - it goes straight up and out.
7. Unclip the two clips at the intake vent (if he drain housing is still in the car) and the lower assembly will come out and will go back in VERY easily. Slide the housing in starting with the deep box end. Make sure when you put it back in to mate up the lower drain at the side of the brake booster.
8. More than likely the foam pieces in the upper housing which looks like a filter and below the windshield will be rotted out. They can be purchased separately at the dealer for about 2 dollars each.
9. Lube the wiper assembly before assembly which is probably dry.
10. Bolt back the wiper assembly and install the remaining covers.
I suggest taking off the battery lead because the electrical box has some fairly big amp lines running through it and you don't want to arc anything or short anything to ground. Could mess up the computer any other electrical components.
I wish I knew about the center firewall removal before pulling the box. I takes time to remove everything but it lowers the frustration level and it prevents breakage.
1. The firewall center is removable and this has to be taken out. I figured this out this morning when I started looking around. Figured MB had to engineer a way to remove it easily. Its a pain and lots has to come out but it will give you plenty of room. There are two bolts on either side - one just above the duovalve and the other near the brake booster There also is an ac line near this point and the bolt holding it should be removed to just slightly give you some access to the bolt and to move the ac line out of harms way.
2. Next - Disconnect the battery and open the wiring junction box which is next to the duovalve. Remove the two wiring harness connectors and a third long single connector. There also is a very small connector with a single wire. I wouldn't move things around to much because the wiring is fairly old and you don't want to break anything. The entire assembly needs to be gingerly moved off the firewall shield which is held by two clips which have a ziptie through them. The rubber grommet simply pulls up with the wire harness though it.
3. Pry off the tops of the two rivets that hold the asbestos shielding and remove it. Now remove the two bolts holding the firewall shield.
4. Gently pry off the brake booster vac line at the brake booster. This goes through the firewall shield. Pull it through.
5. Remove the vacuum line (white) going through the shield - it snaps at a connector.
6. Lift up on the shield - it goes straight up and out.
7. Unclip the two clips at the intake vent (if he drain housing is still in the car) and the lower assembly will come out and will go back in VERY easily. Slide the housing in starting with the deep box end. Make sure when you put it back in to mate up the lower drain at the side of the brake booster.
8. More than likely the foam pieces in the upper housing which looks like a filter and below the windshield will be rotted out. They can be purchased separately at the dealer for about 2 dollars each.
9. Lube the wiper assembly before assembly which is probably dry.
10. Bolt back the wiper assembly and install the remaining covers.
I suggest taking off the battery lead because the electrical box has some fairly big amp lines running through it and you don't want to arc anything or short anything to ground. Could mess up the computer any other electrical components.
I wish I knew about the center firewall removal before pulling the box. I takes time to remove everything but it lowers the frustration level and it prevents breakage.
