99 Monatana Water Pump

[pvisser]

Hello we have a 99 Montana. The water pump has a slow leak, and I would like to replace it before it becomes a real problem.

I am just looking for some quick tips to make the replacement as smooth as possible.

Thanks
Paul

[1999montana]

Paul,

This is one repair that you won't have to stand on your head to do, literally.

The water pump is hidden behind the pulley that drives it.

This is what I did:

Drain the coolant until it is below the top rad hose and pump; about 5 to 6 liters, I think.

Before you release the tensioner, loosen the four bolts (think it's four) that hold the pulley onto the pump, then release the tensioner and remove the belt.

If you forget and remove the belt first, you can place a big screwdriver across the face of the pulley and catch two of the bolts (to prevent the pulley from turning) while you loosen one, and then just repeat the sequence until you have all of them loosened.

Remove the bolts previously mentioned, and tap the face of the pulley carefully with a small hammer to loosen the grip and it should slide right off. Be careful not to bend it by trying to pry it off.

This would be a good time to replace the upper and lower rad hoses if you haven't done it already, just drain the rest of the coolant out so that you don’t cover the ground with coolant.

I filter the coolant through a rag placed inside a funnel into a suitable container (to catch anything that shouldn't go back in the rad) and hold the coolant for re-assembly and top up (this assumes that the coolant is still serviceable and not past its life of course).

There are about 6 or 7 bolts in the water pump housing. You will have to feel around for a few of them on the underside.

Before you remove the pump, compare it to the new one, and reference the orientation of the old pump (to the face of a clock noting the notch / tab that indexes to the water pump housing on the engine).

I didn't, and then spent 20 minutes rotating the pump housing until I could get all the bolt holes to line up so that the bolts would go into the housing properly. I thought it didn't matter as long as the weep hole was on the bottom, but I think it ends up down and to the right or left for some reason.

I used some RTV sealant on the gasket to make sure it sealed. I didn’t follow any torque specs on the bolts to the housing or the pulley. Just use common sense and make sure they are good and snug. As a rule, go around the pump in a circle to make sure the pressure is even. I’d think no more than 15 ft/lbs would be right. Someone may have the right spec though. The pulley bolts are ‘Fn’ T’ torqued, :sarcasm1: meaning you don’t want them to fall off, but you don’t want to torque them a half turn past stripped either.

The rest, you should be able to do in reverse order.

I know some of this sounds vague, but it was over two years ago now and I haven't revisited it since.

[Cressidaadr]

Good writeup. I had forgotten about getting the bolt holes lined up and like you said, I was frustrated with this as well and it took many tries to get it to fit.