I'm really stuck. Bought a '94 940 that's been butchered by at least one mechanic.

Need to replace a mashed up mushroom gasket that's causing a coolant leak. The nut holding the return line to the back of the water pump is rounded. Really rounded. Won't budge.

There's no room to maneuver vise grips. A nut buster won't fit either. I'm thinking of cutting the nut off with my Dremel. Maybe the whole stud.

So is there a tool I can use I'm unaware off? Perhaps a secret technique for removing the nut? And if I get really desperate and lob off the stud, what surprises am I in for when I pull the pump off? Is the stud attached to the back of the water pump? Is it easily replaced?

Thanks so much!

Roger

Chris and spook, thank you for all your help. Much appreciated.

I'll head to my Volvo parts counter in the morning and pick up the suggested parts. I'll try the screwdriver technique first. If that doesn't work then I'll cut the stud off and replace that too. And yeah, I've been spraying this thing with PB for the past couple of days.

I've been topping off the coolant system with water after each trip. No sense in wasting good antifreeze. But I gotta get this job done before the New England cold weather sets in.

Dear Lovemy940s,

May this find you well First, saturate the bolt head and the nut with PB Blaster, an unusually effective penetrating oil. Give it a few hours, or longer, if you can spare the time. The penetrant will work its way through micro-channels in the corrosion, and ease removal.

Next, using an emery cutting disc and a Dremel Moto-tool or equivalent, cut a slot in the head of the rounded fastener. You should be able to turn it with a screwdriver, with a wrench on the nut. Or, you may hold the screw with the screwdriver while you remove the nut with a wrench.

The screw is Volvo part #982759 and the nut is Part #949278. A set will cost about $1.25 at a Volvo dealer.

I'd recommend using a Volvo brand sealing ring, when you re-install the coolant tube into the back of the pump. The Volvo brand sealing ring has a slight radius (curve) along the edges. This eases installation. Aftermarket sealing rings have a square edge.

Hope this helps.

Yours faithfully,

Spook

I believe if you look closely, you'll find it to be a bolt and nut rather than stud/nut. If that's the case, you may be able to grind the head off the bolt (on the front side of the pump) and drive the shank on through.