sheared bolts on front bracket

I have a 1987 astro that is baffling me. It has the horseshoe shaped bracket on the front of the engine that the power steering pump, the alternator, the air conditioner compressor and the tensioner pulley bolt to. This bracket is bolted to the front of the block with several bolts. There are two bolts below the power steering pump that fasten the bracket to the block and they are about 1 inch apart. These two bolts have twice sheared off at the head. When it happens the bracket comes lose just enough to flip the belt off. I cannot figure out what is causing this to happen. I am afraid to put the van back on the road until the problem is solved because it happened once with my wife and children and both times I had to have it towed home. Can anyone help me?

Jameslh

I've had the same thing happen to my 1989 Astro LT.
I replaced the horseshoe (horsecollar) bracket (mine had a tear in it by the power steering pump) and the bolts.
There is also a bracket behind the power steering pump that was broke. I had to replace that also.

The bracket on the back is the key, if it gets loose the front bolts will get all the pressure and will pop off. I had the same problem. I used oversized bolts on the front two, and made sure the rear bracket is secure.

The back bracket is everything. Mine just broke again. Just the back bracket. Torn in two by both holes that mount to the engine. New bracket cost ~$18.00 from the dealer. Horseshoe bracket is torn again as well, but I'm not replacing it this time. Not at $400.00 a pop. Thankfully the front bolts didn't shear off this time. I put in real hard ones last time.

Strong indicator that one or both brackets are broke is power steering fluid leaking from high pressure hose right behind the power steering pump.

I went through this ordeal twice, before I noticed how important the rear bracket really was. I am considering welding in some reinforcements at key points of the "HorseShoe" bracket on the PS side. It really annoys me to know that it could still happen again at any moment, I think I will get the welder out, and use "LockTite Red" on the nuts & bolts. It really is one of those things that could have been designed better, but at least I can make it stronger, before mine cracks too.

I had the same problem when I had my 1987 Astro. I have a few friends that have GM full size vans and if actually look at there engine set-up, it's no different. But it gets better look at our problem area by the Astro's power steering pump and look at a GM V8 engine, they have an easy fix - a support bracket and it works. Hope this helps.

A question for my own "edification".
If the head sheared off the bolts, what did you do to get remaining threaded shaft out?