What could be causing this problem?

[1974vette]

when i floor my '74 from around 45mph and do not let off of the accelerator until im around 70 mph, the bolts that secure my water pump to the engine loosen up and my coolant begins to leak. this is the 2nd time that this has happened and i do not think that it should be doing this...if anyone could help, i would be very appreciative.

 

[ArkShark]

I would guess a small vibration is causing the bolts to 'rattle' loose.
I have no idea what could cause that. Could be lots of things.

A temporary fix would be to try using some lockwashers & loctite next time you install the bolts.

Anything else rattling loose? Have you checked all the other engine bolts?

 

[Bob Chadwick]

Are the bolts actually coming loose as measured with a torque wrench or are they simply leaking. If you don't coat a couple of those bolts with Permatex, they will begin to leak because they go through the water jacket.

 

[1974vette]

arkshark, sorry i forgot to mention, but i already have lockwashers on the bolts...

bobchad, the bolts are actually coming loose...i had to retighten them after pulling into the driveway

thanks for your replies...maybe we can figure something out....

 

[mvftw]

I agree, you can use teflon pipe sealant

 

[Bob Chadwick]

Are you torquing them to specs? I think it is JohnZ that explains stretching and tension holding bolts in place. I think it called for either 30 or 40 ft/lbs but I would need to check my AIM to confirm. Let me know if you need this info.

Mine are torqued down to specs with no lock washers and don't come loose.

 

[4 webers]

It is a not so common problem , and tightening the bolts , locktite, sealant, lockwashers etc, will not cure it . It is a fan clutch or fan balance problem , they show up every now and then in the dealerships. It should be tended to soon ,,,,,,,,,,,, have seen a few get a bit out of hand and sorta eat related components ,,,,,,,,,,,


geo

 

[1974vette]

one of my buddies mentioned something about it being a problem with the crank...i have no clue though...thanks for all of the replies...i will get it checked out ASAP