took my heads off the other day to port and polish them because I had a blown head gasket. Put them back in and could only get one of those two bolts back in on the reverse flow coolant tube behind the heads. One of the bolts will hand thread about 1/4 of the way and then will start to go crooked and it too tight to turn. The bolt threads are fine and I even swapped the bolts to see if it would work right and nothing. If I can get the stupid thing to thread how can I seal up the hole and still have it flow coolant? Sorry for the long post but I've been working on my car a week and now it finally runs right and it sprays coolant everywhere Ahhhhhh

 

get a new bolt. I had to oder one because one of mine was screwed up I looked up the # in the parts manual that shoebox posted long ago and ordered it from GM parts direct.com

 

yeah I finally got it fixed. It wouldn't thread all the way in so I bought two more washer/gaskets to put on the bolt. I ended up with 4 rings on it but it bridged the gap and stopped the leak. Everthing works great now

 

well I thought I had it fixed but when the car warmed up and the pressure build up it started leaking a lot. I just don't know what to do. The car's been broken for over a week now and this is the only thing keeping me from driving it.

 

I would talk to a local chevy dealer and find out the exact thead of the bolt, then go buy a tap and chase the threads into the head. You might just have a metal piece in there.

 

yeah I found out the size tap I need except I can't find it anywhere. I spent 3 hours the other day looking for this odd sized tap. 1/2 13 fine thread I can find coarse thread everywhere but not fine. It's driving me crazy

 

Those are tough to put in and in an ackward position. Mine went in crooked MANY times. But I eventually got it. Based on my experience, I would keep trying. Do you have a cheapo mirror or something to see if there is any problems with the hole? Also, once they are in straight, they still need some good torque to screw in, they won't screw in with just your fingers.

 

look online.

 

Find the right tap. Check with machine tool suppliers. They carry or can get anything. Worst case senario (and I don't recommend...), you could move up to the next size tap that you can find and the correct bolt for the new size.

 

I would love to tap it to the next size except you can't get that bolt in the next size. It's a special bolt with holes in it and one going through the center. I'll just keep trying to get it in

 

The thread is 1/4 pipe thread. It is not tapered. If you use the tapered pipe tap, you will enlarge the hole and you'll have to get custom fittings. I did this anyway. Got some nice fittings and some braided stainless hose and it looks and works great. No more banjo bolts.