Broken water pump bolt

[alfari]

So after reading up on the Cardisc and reading all the extremely detailed threads on timing belt replacement and gotchas to watch out for (thank you Alfisto Steve, Black Alfa, Sean, Jason, and everyone else) I felt comfortable enough that I could tackle the timing belt change with the help of my Fiat guru father-in-law keeping me in check.

Everything was going extremely well, cams lined up with Rick's template at TDC, got the belt on, put the brand spanking new waterpump on with new gasket and gasket sealer on both sides of gasket, start to put back in the twelve bolts connecting the pump to the head, and on the last bolt......I think I stripped the threads or broke the bolt.

At this point it was late in the day, and rather than try to work any further on it I decided it would be better to come back to it after getting some rest, and didn't want to face what had happened and so didn't pull it out to see what had happened.

I found one other thread here where this has happened to someone (Sean) and he successfully continued on without fixing the bolt but as we know the engine didn't make it to the next TB change for other reasons (hope you have it back on the road soon Sean). I'm tempted to do this, but being that it is a pressurized system and the location of the bolt that broke/stripped has me worried about doing this.

This happened to the first top side bolt on the left side of the middle housing that goes upwards to hold the thermostat, the one at about the 11 o'clock position.

Should I:
1) Leave it - the location is ok and the gasket sealant on both sides should prevent it from leaking
2) Face the music, pull it out and correct it, whatever happened. If so,
a) do I need to replace the gasket as it has been tightened down
already?
b) what size are the ten larger of the twelve bolts.

I know I'm going to get flak for not determining if it was stripped or broke, but after many hours working carefully and worrying about the timing belt I just wasn't ready to face this at the end of the night.

Thanks in advance,
Spencer

[elite38868]

Don't you hate it when that happens?

Can you take a picture of the location of the bolt or find a picture of one and show us which bolt. I'm more of a visual person. <s>I had this same problem and it never leaked, but it depends on which bolt</s> (duh, you just said it in your post!!).

Also, just read the rest of your post! When I was taking apart my engine, I was proud to find the timing spot-on and the waterpump leak-free So, hopefully that means I did a good job, LOL.

[Richard2]

Personally, I'd feel better fixing it. Did I mention I have a couple of helicoil kits? Guess why.

[goats]

regardless of whether its broken (easy fix) or stripped (pretty easy fix) you gotta fix it as Richard says. You would HATE to put everything back together to find a drip-drip-drip-drip.

Working on any of these blind threaded holes in any material, and any threaded holes in anthing other that steel, a torque wrench is a MUST-HAVE in my view

[alfari]

Sean: Here is a photo indicating the location of the bolt (not my waterpump, swiped from another thread).

Goats, Richard2: You're right, I would not like to get it back together to have to take it apart. If both cases are an easy fix then I shouldn't be taking the chance.

Both before and after this happened I did not see anything in cardisc about maximum torque for these bolts. Does anyone know what the spec is so I don't make the same mistake again? Any advice for when fixing?

Thanks guys, I'm feeling better about this.

[Richard2]

I haven't got my manual here, but I'm pretty sure some where it list torques for different size bolts/studs. It won't list torque for water pump mounting bolts, but will give you a general torque for bolts that size.

[goats]

shows water pump bolts torque 5.9 - 6.9 ft/lbs

Thats SKINNY for a ham handed guy like me (no 3/4 drive needed there -- less is more!) ! Thats why a torque wrench is a MUST HAVE!

Same applies to
a) valve cover bolts on old American Iron
b) Auto trans pans on any car!

Take the pump off again and see what the scoop is with that bolt. If you need to helicoil it, I would say DO IT but then again, there is enough beef there to drill and tap (and at 6.5 ft/lbs you dont need much) and Mech Eng 101 (or was it 102, it was so long ago!) says your only need 3-ish threads to get 95ish % of the tension strength-- I know Mr T can chime in here as can a good number of our esteemed digesti---If you drill and tap, you will need (maybe??) to enlarge THAT HOLE on the pump to accomodate the larger bolt. IF YOU DO, Please mark that hole on that pump with an identifier so that the NEXT TIME you will know to ream it out a smidge (only if needed to clear the ?12? mm bolt)!

[jhutton]

the same thing happened to me, so i feel your pain, i had about 10 different bolts that broke when i did the timming belt water pump job on my car. just take the time and drill them out, and make sure you use anti seize on the new bolts. it seems the last person to rebuild my engine didn't use any and i cause me a bunch of headaches.

[ChazzyD]

I'm 99% sure that you stripped the threads in the engine block. The bolt is steel and the block is aluminum. The bolts are not long enough to get enough threads IMHO. Especially if you put the wrong bolt in the wrong hole. You may have enough threads in the block to put a longer bolt in and not have to do anything else besides chase the threads with the proper tap. Pull the bolt and see before you remove anything else and save a lot of hassle. You have to test fit every bolt into a w/p hole to see if you have the right bolt in the right hole before you ever attempt to bolt the w/p on to the block. Even then, they could be longer IMHO. They don't need to be very tight to seal properly, they are small bolts and don't need much torque. I don't think some of them will grab more than 3-4 threads, so stripping them is a sure thing without a torque wrench and the wrong bolt in the wrong hole. The w/p change makes me nervous when I do one.
Charles

[alfari]

Thanks for looking that up goats, I was looking in 0-35 through 0-41 expecting it to be there. I'll be working on it tomorrow or Sunday so we'll see how it goes. I'll probably have to make a new gasket as I've been told the sealant will likely cause it to not come off in one piece.

Will definitely be using antisieze, plus replacing any of the suspect looking bolts.

Thanks everyone.

[Alfisto Steve]

Spencer why don't you measure depth of the hole and length of old bolt before you remove the pump to see if bolt was shorter than hole. If so get the correct size tap which I believe is 6 mm x1.00. Check bolt to be sure that is correct tap as I am away from my tools and parts today.

Retap hole and get longer bolt to match hole but with thin washer besure it does not bottom out in the hole and head and washer go flush on top of pump housing.

Do not use extra washers as tensioner goes over that area and bolt head can not protrude in its way.

[MrT]

I stripped (I think) exactly this bolt hole once. I found that the bolt that was going into the hole was quite a bit shorter than it might have been, and was engaging only a few threads. At least six more were available for the longer bolt I used, and I was able to torque it to proper spec once I realized that MY CHEAPO TORQUE WRENCH WAS MISCALIBRATED BY 10 FT LB. Ouch. Get a 5 lb sack of flour and put it 1 foot from the socket and make sure (with the wrench parallel to the ground) that the 5 ft lb setting clicks there. Accept no substitutes. You can make this test on ANY bolt, including the wheel lug bolts. They don't have to move, just provide a stable reference point for you to test the calibration of the torque wrench.

Michael

And as Steve says, Do not use extra washers as tensioner goes over that area and bolt head can not protrude in its way." Guess why he knows that....

[Alfisto Steve]

The reason is we found Michaels 93L came to him that way and we had a few tense moments with tensioner and timing belt running true until we found bolt preventing tensioner from working correctly as belt kept wanting to ride off cam pulleys as I remember.