Replacing a water pump

Basic Car Repair

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1.	Checking fanbelt tension
2.	Adjusting fanbelt tension
3.	Fitting a new fanbelt
4.	Draining the cooling system
5.	Flushing and cleaning the cooling
6.	Checking the thermostat
7.	Changing a hose
8.	Refilling/adding anti-freeze
9.	Checking a radiator pressure cap
10.	Replacing a water pump
11.	Checking an air-cooled engine system
12.	Shim-adjusted overhead camshaft
13.	Pushrod and rocker
14.	Overhead camshaft and fingers
15.	Checking externally-adjusted
16.	Renewing engine mountings
17.	Fitting new steady-bar rubber
18.	Changing an exhaust manifold
19.	Changing the oil
20.	Changing a cartridge filter
21.	Cleaning a bowl-type filter
22.	Cleaning a centrifugal filter

Although a defective water pump will leak coolant, this is not always obvious because it is dispersed around the engine bay by the drive pulley or fan.

If there isa persistent water loss, but checks on hoses show no apparent leaks, it is pos- sible that the seal on the pump spindle is damaged and is allowing water to leak through the pump bearings. As a rough guide to pump condition, loosen the fanbelt (see Look- ing After the Fanbelt’) and try to rock the pump spindle by mov- ing the pulley up and down. If there is more than a fraction of free play, the pump is probably leaking. Leaking pumps some- times make a squeaking sound, but a squeaking pump is not necessarily leaking— carry out the spindle test before deciding to renew it.

Replacing_water_pump

Step 1. Drain the coolant and remove the top and bottom radiator hoses at the pump.

2. Slacken the generator mounting bolts and remove the drive belt. Where the pump has the radiator cooling fan attached, undo the fan-blade attachment bolts from the pump pulley and remove the fan. If there is insufficient clear- ance to remove the fan blades,undo the radiator cowl, or if necessary, remove the radiator.

3. Using a suitable socket extension bar and wrench, undo the attachment bolts or nuts round the outer edge of the pump. If the pump is linked to the cylinder head by a small- bore by-pass hose, remove this. Draw the pump from the engine, if necessary lightly tap- ping it sideways with a mallet to jar it free.

4. Scrape any dirt and the remains of the old gasket from the front of the engine. Fit a new gasket to the new pump, holding it in place with non-setting sealant. Smear sealing compound on the gasket seat- ing on the engine. If the pump has a by-pass hose fit a new one, with new clips, first attach- ing it loosely to the pump stub.

5. Offer up the pump to the engine, if necessary fitting the by-pass hose on the cylinder head stub—thread the hose clip on the hose first.

6. Tighten the securing bolts or nuts evenly round the edge of the pump. If appropriate, tighten the by-pass hose clips, then refit the radiator hoses, fan and radiator, re-tension the fanbelt and top up with coolant.