Just an update and another thank you for all of the helpful tips and comments.

Of the two sheared bolts, one had enough length protruding from the block that I was able to use a pair of vice grips to grab and unscrew the bolt. The other bolt was sheared flush with the head. I actually had trouble finding a left-handed drill bit at the local auto parts store, so I gambled on a screw extractor. I drilled into the bolt with a regular drill bit, then used the extractor successfully to remove the second bolt.

After cleaning everything up and using a new gasket and set of seals for the waterpump, I was able to get it installed without much drama. I ended up using both methods described in the comments to lever the pump upwards to compress the top seal. I inserted a small phillips screwdriver in the top bolt hole to wedge the pump upwards, but it was not enough to line up the lower bolt holes of the pump with those in the head. So I used a floor jack with a length of 2x3 to wedge the bottom of the pump upwards enough to get all of the bolt holes in the pump to line up with those in the block.

Once I tightened everything up, installed the rad hose and belt, and filled with coolant, I had no leaks. 30 min test drive on the highway showed no coolant loss.

Thanks to everyone who provided advice.

Jas945
93 945 NA

Thanks for the great responses. I assume that the bolt sheared off with little or nothing protruding from the block. I say assume because after the bolt sheared, I gently closed the hood and went inside my house for a beer. I haven't been able to motivate myself to go out and look at the aftermath yet.

I didn't think of using any mechanical advantage to lever the pump to compress the top seal, so that was likely my problem with fitment. I will definitely use either a pry bar or a floor jack on my next try.

I may have to try the drilling method described, since I am trying to keep to a budget and either having the car towed or removing the engine is not an option at this point.

Jas945

When I was faced with a broken water pump bolt, I was able to use a 90 degree angle drill to drill into it. It's very important to keep the hole centered in the bolt as perfectly as possible. That way you can progressively advance to a larger drill bits without hitting the threads. The larger the hole you can drill, the better your chances of being able to extract the remains. Drill a little - check with a mirror - drill a little more - check with a mirror, etc..... Using left hand drill bits isn't a bad idea either.

If the pump is still in place and if the bolt hole in the block is well centered with the pump's bolt hole, you may be able to use a short piece of steel tubing pushed into the pump hole as a drill guide. If you can manage to drill through the bolt with a large enough drill, without exceeding the minor thread diameter, you can sometimes grab the remaining thread "coil" with a pair of needle nose pliers and pull it out without using an eze-out.

A lot of the aftermarket pumps have lousy castings. Sometimes it helps to take a rat tail file and clean up the bolt holes a bit before installing the pump. There should be two holes that are slightly elongated. I forget if there are studs in those two holes or bolts. But what you do is, using just those two, slide the pump on, press upward on the pump (compressing the hat seal against the bottom of the head) with some sort of pry bar, and snug those two bolts/nuts just semi-tight just enough so the pump can't slide back down. Then install the other three fasteners and snug all five evenly to the final torque. Note the bolts/studs are only 6mm? dia so be careful to not overtighten and break them. You can save yourself a possible headache by first fitting the pump to the engine with no gasket or seal, and with all five fasteners screwed part way home, make sure you can slide the pump all the way up against the head. If you can't then you need to clean out the offending hole(s) with the rat tail a bit more.

Another problem with a lot of the pump castings is that the little edge where the timing belt cover lays on it, it's sometimes so crappy that the cover doesn't sit back where it should and ends up dragging against the back edge of the pulley. Take a look at the casting in that spot and if it looks like it could be an issue clean it up with a file before installing.
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (fixed the brake fluid leak - now on to the ignition)

Dear Jas945,

Hope you're well. I want to be sure I understand the problem. Is the sheared bolt brand new? If so, it must be defective.

Most of us, who have replaced water pumps, have sheared bolts that corroded over 10-15 years. I don't recall a post reporting the shearing of a brand new bolt. That's why I presume the brand new bolt was defective.

Is the bolt sheared flush with the front of the head, or does a short stub extend beyond the head's surface?

In either case, saturate the bolt with PB Blaster, Kroil, or a similar penetrating oil. These oils work their way through micro-channels in any corrosion. If corrosion isn't an issue, the oil lubricates the bolt. That eases removal.

If there's a stub of the bolt protruding, try to grip it with a vise-grip pliers. Before trying to remove it, tighten it ever so slighty, e.g., one-thousandth of an inch. Then, see if it will turn-out.

If the bolt has sheared flush with the head's surface, you may be able to weld a stub of metal to the top of the bolt, and then turn it out.

If the bolt has sheared below the front surface of the head, you'll need to pull the head and have a machine shop drill-out what remains of the bolt. It will be next-to-impossible to do this without pulling the head, because holding the drill steady - and keeping it centered in the middle of the broken-off bolt - is not easy, to say the least.

I'd avoid use of "bolt removal". The water pump bolts are so thin, that inserting a tool into them is likely to jam the bolt, such that the head will have to be removed, so an automotive machine shop can drill-out the broken bolt.

As to installing a water pump, I use a bottle jack and a piece of wood gently to lift the pump, and compress the doughnut seal at the pump's top. The jack holds the pump in place, while I gently snug the bolts and nuts.

I'd not re-use the old bolt. A Volvo dealer should have a bolt set, for small money. When tightening the bolts/nuts, go gently. While the system is pressurinzed, the pressure is not so high that super-tight is required.

One final thought get genuine Volvo seals. They work better than any aftermarket unit. Volvo brand seals go on easier, seal better, and last longer.

Hope this helps.

Yours faithfully,

Spook