I have a 99 Astro with 75,000 miles that appears to be leaking coolant out of the weep hole on the water pump. It leaks only when the vehicle is on an incline and not when parked on a level surface. Why is this? Does the water pump need to be replaced immediately or can I buy some time? If the pump is to be repaced,is the “special tool” needed to remove the fan from the pump or is there an alternative? Any other advice would be appreciated and if the pump needs to be replaced, some pointers on what to look out for. I do have a Haynes repair manual, but it mentions nothing about the “special tool”. Local mechanic quoted $300+ to replace.
Yes you do need to replace the pump, because the internal seal on the shaft bearing is failing, and it will fail more and more in short order. Follow the step by step in the Haynes. I always use High Tack sealant on both the pump, both sides of the gasket, and the block to assure a good seal. My old dad used to coat the inside of the pump and the timing plate with rubber cement to prevent corrosion, but I have never tried that because it sounded fishy to me. Use a torque wrench to thighten the bolts, and clean the bolts first.