Sheared water pump bolt

callahanoffroad · Post by **callahanoffroad** » 10 Feb 2019, 14:21

Hello everyone!
Long story short I was finishing the water pump installation and noticed it was dripping coolant. So I pulled out my torque wrench, set it to 15 lbs/ft, checked all the bolts again. Got to the bottom bolt and it promptly broke off inside the block. These were new Volvo branded water pump bolts! So I'm just dumbfounded as to what to do. Half of the bolt is stuck in the block and I am not sure how to even get it out. Plus the water pump is behind the unibody so I cannot get a drill in there. The good news is that I've officially changed a Volvo timing belt and that gives me something to celebrate.

Any ideas or advice? I'd really hate to have to pull the engine block to get that single bolt out!

Post by **oragex** » 10 Feb 2019, 14:33

How about the torque wrench? Give it a check, left under tension it goes off calibration - here's a small test www.youtube.com/watch?v=4IvozfdbXRo

I bet that bolt took more like 30-40 ft/lbs or so so the wrench is pretty under suspicion at this point

As for the bolt, no worries - I' rather worry about the other ones because you'll need to pull them and use a gasket maker - such as this guy here - on both sides of the paper gasket https://www.autozone.com/sealants-glues ... 516195_0_0
Not too much of this sealant, really just a thin film on both sides, so it doesn't leak inside when the bolts are tightened (also read introductions for application and dry time). The sealant will dry and stick and seal the paper gasket.
If the torque wrench was indeed off, I'd fix it and put in there a new gasket and fresh set of bolts because the ones you have now are already stretched to the breaking point (remove them smooothly). 15 lbs/ft is quite easy to guess by hand, it's not a big torque, and the paper gasket makes it even easier to 'feel' because you'll notice the gasket starts crushing under torque - it should crush a little (say 30%-50% of it's thickness) and that's it. I would even only use 2-3 fingers on the wrench to get such low torque. No worries about a missing bolt, there's already a ton of them to hold the pump. By the way, the tensioner center bolt has the same torque I believe.

Use only distilled water in there

(I mix with the the Volvo concentrate)

callahanoffroad · Post by **callahanoffroad** » 10 Feb 2019, 14:49

oragex wrote: ↑10 Feb 2019, 14:33 How about the torque wrench? Give it a check, left under tension it goes off calibration - here's a small test www.youtube.com/watch?v=4IvozfdbXRo

I bet that bolt took more like 30-40 ft/lbs or so so the wrench is pretty under suspicion at this point

As for the bolt, no worries - I' rather worry about the other ones because you'll need to pull them and use a gasket maker - such as this guy here - on both sides of the paper gasket https://www.autozone.com/sealants-glues ... 516195_0_0
Not too much of this sealant, really just a thin film on both sides, so it doesn't leak inside when the bolts are tightened (also read introductions for application and dry time). The sealant will dry and stick and seal the paper gasket.
If the torque wrench was indeed off, I'd fix it and put in there a new gasket and fresh set of bolts because the ones you have now are already stretched to the breaking point (remove them smooothly). 15 lbs/ft is quite easy to guess by hand, it's not a big torque, and the paper gasket makes it even easier to 'feel' because you'll notice the gasket starts crushing under torque - it should crush a little (say 30%-50% of it's thickness) and that's it. I would even only use 2-3 fingers on the wrench to get such low torque. No worries about a missing bolt, there's already a ton of them to hold the pump. By the way, the tensioner center bolt has the same torque I believe.

Use only distilled water in there (I mix with the the Volvo concentrate)

This is actually a great idea. I think I'll take an Uber up to the store tomorrow morning and see what happens! Thanks!

Post by **cn90** » 10 Feb 2019, 15:06

A quick note on Click-Type Torque Wrench, I used to like it, it is fine but requires calibration etc.
This type is good for tight space when you just want to hear a "click" but again it can be mis-calibrated.

I now use Dial-Type Torque Wrench, it is low-tech but reliable.

I'd worry about all of the other bolts as they might have been over-torqued.

- If I were you, I'd go to dealer and get all new bolts and another paper gasket.
- Remove the WP, toss away all other bolts.
- Use new gasket and re-install the WP.
- I just snug the bolt and tighten a bit further, sorry I have fixed car for so many years, so I go by "feel".

Post by **theWIFES_S70** » 10 Feb 2019, 17:57

cn90 wrote: ↑10 Feb 2019, 15:06 I just snug the bolt and tighten a bit further, sorry I have fixed car for so many years, so I go by "feel".

I also use the dial-type torque wrenches, too. (Hello Craftsman!) So sorry to read about this broken bolt, what a pain to drill out and tap. But yes, it would only break off like that at 30-60 ft/lbs if you ask me. (Probably higher.)

Crazy how much some of do by feel on our cars!

Post by **cn90** » 10 Feb 2019, 18:24

- Actually for broken stud, it is easy, especially when it is fresh...

- If it is broke flush with the engine housing, then use a punch tool to tap at angle to get it out.

- If the stud is deep inside, then watch the video below.
But be careful, you don't have the space for a drill, so you will be to use a right-angle adapter!
Then you don't have direct visual view (tight space), you may damage the threads!

Anyway, it all depends where it is broken...

Post by **cn90** » 10 Feb 2019, 18:29

Below is the thread on using right-angle adapter drill...

Stripped Water Pump Bolt
viewtopic.php?t=39495

Post by **cn90** » 10 Feb 2019, 21:55

You may be lucky...the broken bolt you showed is probably flush with the mating surface.

I borrowed a photo from the web, is the broken bolt at 6 o'clock position?

Post by **j-dawg** » 11 Feb 2019, 01:25

cn90 wrote: ↑10 Feb 2019, 15:06 A quick note on Click-Type Torque Wrench, I used to like it, it is fine but requires calibration etc.
This type is good for tight space when you just want to hear a "click" but again it can be mis-calibrated.

I now use Dial-Type Torque Wrench, it is low-tech but reliable.

For sensitive applications, I check my clicker against my beam-type wrench - torque a sample bolt with the beam to the desired setting, mark the head, repeat with the clicker to verify it's close. This gets me the convenience of the clicker without the worry that it's wildly out of calibration. I've found that once I set the clickers they're very consistent from one click to the next, and my Harbor Freight cheapies have been consistent when I un-set and reset the torque too, but the number on the dial is liable to be off by a couple of ft lb.

It's more of a sanity check than anything. The relationship between bolt torque and actual preload is fraught with guesstimates, assumptions, and loose correlations. For something like a water pump, consistency across the bolt pattern is probably more important than hitting the exact number.

callahanoffroad · Post by **callahanoffroad** » 11 Feb 2019, 07:20

cn90 wrote: ↑10 Feb 2019, 21:55 You may be lucky...the broken bolt you showed is probably flush with the mating surface.

I borrowed a photo from the web, is the broken bolt at 6 o'clock position?

pic02.jpg

Yes the one at at the 6 o'clock position is the one that broke.

As far as the torque wrench is concerned it was clicking on all the other bolts. I never store it in the locked position. I try to take care of my tools. I was going very slowly and gently bc 15 lbs/ft is just a smidge off hand tight. I KNEW that it was making the bolts too tight. But bc my hands aren't calibrated to lbs/ft I trusted the device. I wonder if it was affected by the super cold weather. Looks like I'll need a beam type in the future!

Alright I'm going to try and fix the car today. I'll report back with success or failure