Note. If the water pump fails, it is best to replace it entirely. However, you can limit yourself to replacing the seal and the shaft with the bearing.
Cross section of a water pump
- a = 25,8 - 26,2 (22,8 - 23,2) mm
- b = 2.0 mm
1 - shaft and bearings (the figure shows the pump with an electromagnetic fan; shaft with viscous fan is longer); 2 - hub; 3 - casing; 4 - sliding ring seals; 5 - gasket ring; 6 - retaining ring; 7 - impeller
1. Fix the water pump in a piece of metal pipe, directing the impeller upwards; then, using a soft metal drift, press the shaft through the impeller and the shaft with bearings through the pump casing. Remove the impeller.
2. Press out the o-ring seal with a punch pointing out the outer end of the pump.
3. Remove the center and spacer rings from the impeller.
4. Clean the pump housing and impeller with kerosene and wipe dry. Keep in mind that the shaft and bearings, together with the fan hub and sealing parts, must always be replaced with new ones.
5. Fix the pump casing with the impeller pointing downwards, then put a drift (piece of metal pipe) onto the outer raceway of the bearing and press in the new shaft and bearing so that the raceway is flush with the end of the housing.
6. Position the pump housing with the impeller pointing upwards and lubricate the O-ring seat in the housing with sealing paste.
7. With mandrel (metal tube) press the O-ring at a right angle into the housing.
8. Install a new spacer ring on the thrust ring. Then lubricate the spacer ring with brake cylinder paste and press the ring into the impeller with the beveled side first.
9. Clean the shaft, impeller seat, and sealing surfaces, then place the shaft on a support and press the impeller flush with the shaft end. Check size «A» (see illustration Water Pump Cross Section).
10. Heat the new fan hub to blue (up to about 300°C). Clean the shaft and use a 2mm metal spacer to install the hub. Put the hub on the mandrel (metal tube), insert the shaft and press it in to the shim. Wait until the hub fits snugly around the shaft, then dip it into the hearth and remove the spacer.