Hi my name is Diesel and I'm the owner and operator of 4u2cdetailing.com. Now what I'm about to do is clean the radiator of this Ford F350. The best way to clean a radiator is to use a bug cleaner. You can get it from your local auto store. What I would usually suggest is taking some soapy water and getting all the paint around the area saturated with soapy water. The reason why is because the bug cleaner is usually really too strong for the paint. Sometimes people use a degreaser. You really don't want to put that on the paint so now that I have all the soapy water on the bumper I will go ahead and spray the radiator down really well. You really don't want to wipe the radiator. You really don't want to use a brush on the radiator because they have gills on them and you can actually ruin the gills. As you can see there is some damage to this one already. That's going to happen but you don't want to be the one to do it especially if you are doing your car or God forbid someone's car, let that soak really well, take your hose, go ahead and put it to stream. Me I usually use a pressure washer but if you don't have access to a pressure washer if you use a water hose or you can just go to one of the $1.25 spray washes and use their pressure washer and all you do as you can see the bugs are just coming right out. Now this one right here he obviously doesn't want to go anywhere so I'm just going to kind of give him a little help and as you can see that's all it really needs. All the bugs are gone. You didn't ruin anything. Every now and then spray the bumper off, spray any painted surfaces around the area just so if it does leak on, if the cleaner does leak on the paint it won't ruin it.