killingmoon65

...and everything was going so smooth! Who has had any luck with easy-outs? What about heat from a small torch? Are all the bolts normally replaced on this procedure? The car is a 78 and these bolts look pretty crappy. Is it recomended to chase the threads as well? Thx. Max
PS Anyone going to the Downriver Cruise in Detroit tomorrow- Sat 24th?

dr bob

Several prominent listers will warn you against using easy-outs on thes tiny (6mm) bolts.

The current wisdom as I understand it:

-- Pull the vise-grips out and use them to grab the little stub end of the broken bolt, for those that stick out.

-- Before you do anything, soak the remaining bolts with Kroil. Poor alternatives are PB Blaster, and maybe WD-40 if you are really desperate.

-- Find some left-hand drills. Use your Dremel to grind the end of the bolt flat. Center-punch the remaining bolt so the drill will stay centered. Drill slowly with the left-hand drill, progressing up in size until you get to about 3/16". The stub should come out with the drill bit. If not, by 3/16" drill and centered on the stub, you should also be close o being able to start pilling the remaining bolt out bit by bit with a small pliers, then with a pick and porceps.

-- Chase the threads carefully when you are done, after getting ALL the old bolt pieces out of the block. Taps come in 3-tap sets, with a tapered- a plug- and a bottoming tap in the set. The taps are pretty hard, so they are also a little brittle. Carefully use the taps in sequence to reform the threads in the block, without breaking any taps off.

RyanPerrella

and definately use new bolts everytime you replace the WP. For the $5 of so it will cost for all new bolts, i would (after being at the clinic Bob hosted) definately always replace all bolts everytime, no matter how good they look. if you still dont drive the car allot if you replace the pump in 6 years your new bolts should still look pretty new assuming you run with an anticorosive coolant. Obviously if you have some that are broken you have to get new bolts anyway, but again if your going to do this or pay someone else to di it, whatever, make sure you just use new bolts. It will save the next owner the nxt time it needs to be done.

S4-on-your-back-door

I used 8.8 grade bolts with antisieze when i replaced my WP. I also had 2 bolts break on me, could'nt ez out them so i just left them in and cleaned around them real good, they now act as studs and actualy helped keep new WP inplace while i bolted it down. you can loose a couple of bolts and be ok, just remember DO NOT OVER TORQUE THESE BOLTS just snug them firmly or you will strip the threads.

perrys4

What Dr. Bob says...Keith will attest to that!! & out of 10 broke on my job,,one easy out broke in the bolt. Had to drill around it and use a heli-coil. Delayed the job 5-6 hours!! Definately use new bolts and use an anti-seize compound on them.....

dr bob

Oh yeah--

-- New bolts Mandatory.

-- Never-Seeze Mandatory

-- Torque wrench Mandatory. This is an inch-pound torque wrench, mind you, in 1/4" drive flavor.

Tom928

Would there be any merit to replacing the WP bolts with studs and nuts?
Of course you would still have the bolt that holds the cam cover.

jeff jackson

Tom...of COURSE there would be an advantage to this replacement...BUT...thei varying length of the water pump bolts is the issue thats hard to be addressed. Might be worthwhile though for one of the major vendors to offering this option in "kit form" replacement / upgrade for users doing the TB / WP replacement maintenance. It would certainly be an attractive option to "repeat" procedure owners anyway...

dr bob

What Jeff said, plus:

It would be an interesting update, provided... that the studs are somewhat stronger than the bolts they replace. The temptation would be to try stainless studs, a little threadlocker, stainless nylok nuts with flat washers to actually hold the pump on. Getting the tightening torque just right with nyloks is an exercise in patience with the torque wrench, since you need the friction/breakaway torque of the nylok, plus the actual tightening torque on the nut to get things just right.

The effort to acquire and install the studs, and to guarantee that all future owners and/or mechanics would know how to and would actually follow the required torqueing procedure, would be a lot more than that needed to just put new bolts in to the right torque, into holes that had been chased with the correct bottoming tap, with a dab of never-seeze on the threads, etc.

Just my opinion of course.

Fabio421

Socket Head Cap Screws are stronger than a grade 8. These may be a good alternative also. But if you use some anti-sieze on the bolts during the replacement, it shouldn't be an issue if you ever have to remove them.

dr bob

I respectfully disagree. Socket head capscrews are different from hex-head capscrews only in the head where the wrench attaches.

The problems with water pump bolts seem to manifest themselves as breaks/fractures just outside of the block. This tells me that the bolt is being stretched when it's installed, and/or the threads are seized in the block. Buying a tougher bolt may save you some grief later, but only if it's saving you from failing to use the torque wrench and/or failing to use a little Never-Seeze on the threads when you install the bolts. The pump is located by a couple dowel pins when it's in place, so there is no shear loading on these bolts at all. The tension on the bolts with clean threads is not even close to the bolt's capability when the correct amount of torque is used on installation.

Use the right tools, use the right materials, use the right anti-seize, and you'll avoid broken water pump bolts in the future.


Those socket-head capscrews, especially in polished stainless, look great when they are installed. The unfortunate thing is that those bolts are all but completely hidden by the timing belt covers.

Jim bailey - 928 International

I would agree that often the water pump bolts are put in "good and tight" . The installer may stop when the bolts feel "soft" then with a bit of corrosion the next guy to touch it is ..." It " . There is very little pressure in the cooling system the bolts simply do not need much torque to put a lot of pressure on the gasket you get leverage from the thread pitch. Then some like to be "safe " and use locktite. !! One of the big disadvantages of the ratchet wrench is you have the same length of lever no matter how small the socket where standard wrenches the smaller they are the shorter they tend to be simply because you should not need a big mechanical advantage given the low torque value and ease of breaking bolts. And I admit to having broken too many bolts.

dr bob

Let's face it Jim: The biggest guys need the smallest torque wrenches. Too darn easy to use the stretch-it method on bolts. The small bolts suffer first.

JP Rodkey

Here, here. After many years, and a handful of 928 engines, I've never had a problem using 'proper' materials and technique. Over the years, I've acquired four torque wrenches with total range between 1 inch-pound to 250 ft-lbs. and use them to what most would consider a maniacal level. I can't imagine doing any serious work without them - and it's all serious work to me.