Anyone know the size/diameter of screw for the air filter box?

[doity]

It looks like there are 2 large sized Phillips screws that secure the air box.  My car was in storage for awhile and got a lot of moisture in the engine compartment and it is hard to loosen the screws and I think I might have over tightened them previous and I can’t find a screwdriver with a large enough head.  My thinking was if I knew the size I could go to the hardware store and buy the right size tool and new screws.  The old ones are already partially stripped and I don’t want to make matters worse.

 

 

thanks!!

[fordrodsteven]

Mine were also pretty rusted in. I was able to get one out. I drilled out the other and went to the  local hardware store to purchase hex head bolts with the same thread and a small hex. I also ran a metric tap through the threaded holes first when I was putting it back together.

Edited July 9, 2019 by fordrodsteven (see edit history)

[doity]

Thanks Steve.  I took it to my mechanic and he had a problem getting it off.  He eventually used a impact screwdriver and he put some goop around the threads to prevent it from rusting again.

[Barney Eaton]

I thought I would wait and see what responses were posted............so here is my input.

The air filter box is plastic so the female side has brass inserts.......probably needed because the air cleaner should get opened every 10K for inspection.

the screws themselves are M6 phillips head 20mm long...........note the threads are only on the end.    I suspect this screw was used so that they would "feel" tight when you ran out of threads.

A #3 Phillips screwdriver fits the head nicely.

I do not know if replacement screws are available........you might check the pick-n-pull to see if other GM cars used a similar screw on their air box.

A substitute might be the hex head screw pictured to the right..........common screw on GM cars,  25mm long,  and there is plenty of room for the head and it will not trap water like the phillips head.

CAUTION...if you use a substitute screw,  there is the possibility that you can over tighten and pull out the brass insert.....so just screw them down snug. 

[B Jake Moran]

Good information Barney, thanks for adding.  My 1st thought was go to the U Pick It Yard and get under hoods of most Buicks from that era and you would likely find similar or exact screws for future use.

 

2.  No need to overtighten.  Most mechanics "under" tighten. 

 

3. Always make sure especially on Philiips screws to use the right size.  It meets the corners in the screw head for maximum torque. 

 

4. If the fastener does not come out easily, assume some corrosion, even if not seen once out.  In this case,  install the correct size screwdriver, then with it firmly seated, smack it on top with a small hammer or rubber mallet. 95% of the time it will loosen the adhesion.  Then line up the screwdriver and turn.

 

Sorry if this advice is sophomoric and basic but I don't know the O.P.s level of mechanical skills. 

[doity]

Thanks Barney.  It seems that the electric shop that fixed my touchscreen issues was the culprit.  In their notes they mentioned ‘Dirty Air Filter’ but did not reach out to me to see if I wanted it replaced.  And it was pretty bad.  Judging from how hard it was to remove them you would think that they were twice as long

[doity]

12 hours ago, B Jake Moran said:

 

 

Sorry if this advice is sophomoric and basic but I don't know the O.P.s level of mechanical skills. 

Well I certainly can’t do a overhaul on an engine but I do have more than basic level knowledge of tools and mechanics.  I grew up in an era of numerous shop classes and the whole ‘fix it yourself’ ethic.  I’ve done basic stuff on the Reatta like swapping out the CRT, the engine computer, radio box,  etc.