CPS HOLD DOWN BOLT
 

That is what I would do.Bad luck on this one.Put some grease on that bit and tap to catch shards.
I recon you will pull the cover to get room.

Another option would be to helicoil the hole.

I would drill & tap to the next common metric size, which would be M10 x 1.5. You will need an 8.5mm (.335") tap drill. The existing pitch isn't quite close enough to go to a 3/8-16 or 3/8-24.

Another route beside a heli-coil is a Time-Sert. They are stronger than helicoils and don't pull out as easy.

Time-Sert Metric Kits

The CPS bolt hole does not go all the way through the front cover. A real quick measurement looks like you've got about 3/16" of material behind the bolt.

I wouldn't make the hole any deeper, but any of the options above should work fine. It doesn't take a whole lot of torque to hold the CPS in place.

Well, just got back into town this p.m. and have already partially drained the rad., removed the overflow bottle, removed the fan and shroud and the hole is very accessible.
Early this week I purchased parts/materials for several options for the fix:
1. D/T and use a heli-coil for the original 8mm bolt, or
2. D/T and use a 'threaded insert' for the original 8mm bolt, or
3. D/T for a 10mm x 1.5 bolt.

The heli-coil has very 'prissy' threads, but they are steel.
The threaded insert is a solid piece that is very beefy, but requires enlarging the hole to a 1/2", then tapping. I am considering the #2 option.
The 10mm bolt is just a tad larger than the hole in the CPS bracket, but could easily be drilled out for the larger bolt.
I really like the idea of going back with steel threads rather than continuing with the aluminum threads.

Will keep you posted on the final choice.

I vote no on option 2. You don't want to enlarge the thread for the hole to 1/2". Let me find a pic.

Edit: Let's see if this works. Here's the front cover removed showing the CPS hole and your bolt hole. Second picture is the inside part of the front cover. The front cover is not as thick as your bolt hole. You can see the solid raised area cast into the cover that is tapped for the bolt hole. Stick your finger in the CPS hole and you can feel how thin the front cover is. A 1/2" hole might leave too little material around your drill and cause the front cover to crack. I can measure the size of that indention tomorrow if you want to know for sure. I've got a front cover laying around here somewhere.

Chris,

Great pics, advice and info. :-X22

I've got to spread it around or you would have gotten some rep.

Since the cover is aluminum, why not use a self tapping trilobial(sp) bolt of an appropriate length and diameter?

Update please.

Nice pics there Chris.
Here's what I finally did.
I discovered that there were still some threads in the bottom half of the holes so I used a longer 8mmx1.25 bolt and ground it down to where it would not bottom out. I was very careful in tightening it up to make sure I did not strip out the remaining threads.
So far it is working fine.
I finally decided to use the 8mmx1.25 helicoil, but the drill bits and taps are too short to use a drill - stock jobbers drills are not long enough to chuck it up and drill 5/8" deep hole. Taps not long unless you get a 'pulley' tap and I did not anticipate that need.
So, I went back to the method I mentioned above.
I did drain enough coolant to allow me to remove the degas bottle, the fan and shroud.
That gave me plenty of room to work with if I could have done some drilling/tapping.
Those pics Chris took are very helpful.
If this does not work, I will gear up with bit extensions and a pulley tap to go with that 8mmx1.25 helicoil setup.

As always, you FTE guys are on the ball!

Thanks muches,

Larry