Broke a water pump bolt!

[gslender]

Was just tightening the bolts on the waterpump in my NA6 and it snapped - this was only to 15 ft-lbs and the recommended spec is 14-19 ft-lbs !!

So after drilling out tapping and finding a replacement bolt, I carefully did them all hand tight and ignored the torque wrench.

I've never seen that before, but have heard that some bolts, when over tightened can break when next done up to their recommended torque values - I guess also, some bolts need to be replaced.

So what's the common approach - follow the guide and have you had this happen? Replace all bolts first? Hand tighten and hope for the best?

[JBT]

I've witnessed many NA/NB water pumps being replaced and never a broken bolt. Just bad luck I'd say.

[project.r.racing]

Torque wrench correct? In lbs or Nm? 14-18lbs = 19-25Nms for the water pump and oil pump bolts. I have seen mechs confuse the two before my mistake.

Or as above, just a unlucky breakage. Not common but has happened before.

[gslender]

I think I know what caused it... I was a little too generous with the silicone gasket goop to hold the gasket on the pump... a bet a bit of it was squeezed into the bolt hole, and I left it over night to "set" and then the next day when I tightened them, it probably acted as a stop and allowed too much torque resistance.

I've heard this happen when bolts hit an object or protrude too far into the bolt hole - so even a small amount of torque with zero ability to move can cause them to just snap!

Man I swore loudly when it happened.... but, I just grabbed the drill, tap kit and made good!

I'll learn from this and ensure the bolt hole is clear/clean before I continue.

G

[koop21]

i know how you feel gslender, this happened to me too but on my gearbox front cover. Damn gasket goo was the cause of it being over torqued too!