Hello, I am a former farm machinery repairman and as some would say just a cheap skate who does not like spending my hard earned money if I can help it.
So when I went to change my air filter on my 2002 Ford Focus and could not get the screws out because the nuts were stripped out of the plastic housing.
The mechanic said it would cost over $300 for a new air box plus labor to install it.
I decided to repair it.
This pictures is of the box ready to go back into the car.
Step 1: Gather the Needed Tools and Supplies.
You will need a screw driver to loosen the clamps.
A 13/64" drill bit and something to drive it with. (I used a drill press,) a hand drill would work.
A 1/4"-20 Tap and tap driver.
A vise grips, a 8mm wrench and something to mark the holes I used a 5/16" transfer punch,) any way to mark the center and make a punch mark.
A small hammer and a sharp chisel to remove the gussets or a dermal tool, (I used a Dewalt RotoZip tool with a 1/8" bit).
4 each 1/4"-20 stove bolts 1 1/4 or 1 1/2" long
A tube of RTV Silicone Make A Gasket, I used red Permatex Brand.
2 pieces of 1/2" square stock 9 1/2" long either steel or aluminum will work, I used 1/2" square steel key stock because I could buy 12" long pieces at Tractor Supply Co. on Memorial day when I decided to do the job. Aluminum would have been easier to work with.
Once you have the items you need, you are ready for step 2.
Step 2: Remove the Hose From the Air Cleaner to the Intake Manifold
First loosen the clamp on the hose at the air cleaner.
Next loosen the clamp at the end of the hose connected to the intake manifold.
Grasp the hose and lift it off of the intake manifold and then slip it off of the air cleaner.
Lay it aside and go to the next step.
Step 3: Disconect Vent Hose and Electrical Plug.
Grasp the crankcase vent hose and remove it from the valve cover, if it is stuck you may need to give it a twist.
Press the release on the electrical plug and gentle pull it off, don't force it, it should not be real hard to remove.
Step 4: Remove the Air Cleaner Box.
Grasp the air cleaner and lift it out, (I could only show one hand as I needed the other to take the picture) one hand on each end, it may be necessary to give it a slight jerk as it sets in 3 rubber grommets.
Step 5: Removing the Gussets
To remove the gussets I used a RotoZip tool with a 1/8" bit.
Now I could clamp onto the stripped nuts so I could remove the bolts.
Remove the gussets toward the center of the box, leave the ones toward the outside of the box.
You could use a sharp chisel and a small hammer and gently shave the gussets away, just don't try to take to much off at one time or you may crack the box.
Step 6: Remove the Old Nuts.
Clamp a stripped nut with a vise grips and using a 8mm wrench or socket wrench, remove the stuck screws, and remove the cover from the box.
Replace the old 6mm bolts in the cover with new 1/4"-20 stove bolts 1 1/4" or 1 1/2 " long.
Using one of the old bolts screw it into the old nuts and tap them out of the plastic box housing with a small hammer.
Your box housing should look like the last picture, and is ready for the bars.
Time for step 7.
Step 7: Fitting, Drilling and Tapping the Bars.
Now is the time when you are ready for the 1/2" square Aluminum or steel bars 9 1/2" long.
Put them up under where the old nuts were, and you will see where the corner on each end needs to be rounded.
With a file or grinder round the corners so they will fit up against the bottom of the bolt flange and in tight against the sides of the box.
Once they fit, it is time to mark where the holes need to be drilled.
I used a 5/16" transfer punch and tapped it lightly with a small hammer, I could not show tapping it as I needed one hand to take the picture.
I used a drill press to drill my 13/64" holes where the transfer punch had made the marks but you could drill it with a hand drill.
Use a little light oil on your tap to make it easier.
Step 8: Installing the Bars With RTV and Installing the Air Filter and the Cover.
I used Permatex Red Hy-temp RTV silicone gasket maker but any RTV silicone would work.
I put the RTV down one side with the air filter in place then put the cover in place and tightened the 1/4"-20 stove bolts just snug, this held the bar in place while the RTV dried.
I did the same to the other side and then went right on to the next step as the silicone will harden even if you get it into the car and running down the road before it hardens.
WOW it's fixed.
Now lets put it back in the car.
Step 9: Put It Back Together, It Is Fixed.
Make sure nothing is down under where the air filter goes.
Set the box down in place and wiggle it to be sure that it is in the grommets, press it down firmly.
Plug the electrical connector back onto the box.
Connect the crankcase vent hose back to the valve cover.
Replace the air box to intake hose, slip it onto the air filter housing then down onto the intake manifold and tighten the hose clamps.
CLOSE THE HOOD.
You have just repaired you air cleaner box.
You probably just saved your self about $300 or more.