Water Pump bolt issue

[deadflo]

Ok, hoping to get some more advice on my water pump replacement.
Had no issues getting the bolts out, there were torqued on very lightly.

Got everything back on today, put prestone in , and it started leaking right away.
It was leaking from a bolt not tightened enough, one of short bolts, lower right as you face the pump from the front.
Pulled the pulley off again (left the radiator in this time) and went to tighten the bolt further. It goes in a ways, but then just rotates, like the hole is stripped?
Must have been this way before I pulled it out, cause I didnt strip it going in, or cross thread it. 
I tried loosening all the other bolts again,and moving the pump around, thinking I might not have it centered, but it appears to not be able to tighten it.
I am using new bolts from Motorsport.
What next?

 

[siteunseen]

The lower left is a 12mm and the right one is a 10mm, looking from the front. Maybe somebody forced a 12 in there. 

Try your old bolts.

[Zed Head]

I think that every water pump bolt is a different length.  Make sure you didn't get one in the wrong hole.  The threads should grab with at least 1/4" of bolt to go before the head, maybe about 1/2".  Pretty sure also, that under no pressure, you can have a bad bolt and still have no leaks.  I've seen a few broken bolt heads on systems that looked like they were leak-free, even in use.  Not recommended but a sign of something off in your case.  You might have some other issue going on.

[deadflo]

It was one of the shorter bolts, I thought both of those were the same size? When I pulled the bolts out, I put them in an old pump, so I would know which holes they went back in. I will go out and check and see if the other short bolt goes in better. I did try the other old bolt again as well.

[siteunseen]

Mine has 3 long bolts that go to the left side. Skinny at the top, 2 bigger middle and bottom left. 2 skinny shorts go on the right side. One about 2 o'clock the other at 5 o'clock. 

[Zed Head]

A PO might have got them mixed up, who knows.  If you did strip the top threads, or they were already stripped and you stripped the bottoms, you might just run a long bolt in there to the bottom and see how much thread you have left.  Measure travel from when it grabs to when it stops.  Then find an appropriate bolt, or cut a long one to fit.

[deadflo]

OK, looks like I found out what was wrong. I pulled that bolt out, and this is what came out with it. I don't really know what this is, but i'm guessing this must be a a previous "helicoil" fix????

[Zed Head]

Examine your old bolts and see if one has a different thread pitch or size.  It does like an insert but no telling if it's correct for the stock bolts.  It looks oversize, and like there was enough extra room to pull it out of the thread.  You'll need to know size and pitch to insert a new one.

Take it off the bolt and see what the locking portion looks like, at the top under the bolt head.  Just for fun.

[rossiz]

indeed. you may be re-doing that...

[siteunseen]

Yep! I think think it's an m8x125 size you'll need a heli coil for.

[Zed Head]

But if the hole has already been drilled and tapped for the heli-coil/insert, he's kind of limited.  He might just have to do what the last guy did.  Could be an SAE thread.  Doesn't look he did the right work for the stock bolt, that's why it pulled out.

[siteunseen]

That hole is wallard out anyway. You might just put in a bigger bolt. No heli coil

But then you'd need to make the pumps hole larger too.