10.13 - Waterpump replacement ( John Ping,
The following method is applicable to all XJ40s and 4.0 XJSs which utilize the EAC-7325 water pump or some minor derivative of that model. Expect the replacement to consume two hours of steady effort.
Typical hand tools (open end wrenches, 1/2" and 3/8" ratchets & sockets, pry bar, and large flat tip screw driver) is all that is necessary for this job. Its an excellent idea to lay several towels across the engine area (and fender) to protect components ... and to help prevent loss of small parts. A portable fluorescent (cool touch) work light is very handy.
Note: If your pump impeller assembly comes with a gasket, go ahead and install it to the impeller assembly with some silicone RTV sealant. Really helpful to have the gasket in place when attempting to install the impeller assembly ... saves a lot of effort.
1) Disconnect the negative side of the battery. Its not likely that you will suffer electrical problems during this task, but if you accidentally touch a hot connection on the rear of the alternator ... the effort to disconnect the battery will prove immensely worthwhile.
2) Using a 13 mm open end wrench and large flat tip screw driver, loosen the fan thermal clutch nuts (4) on the water pump hub. Wedge the screw driver between the hub and one of the four studs/nuts to secure the hub while loosening the nuts. Using the screw driver, lift and remove the radiator / fan shrould clips (2). In one motion, remove the radiator / fan shrould and fan/thermal clutch assembly.
Note: The shrould has no lower fasteners ... shrould tabs fit into frame slots. Store the fan thermal clutch vertically ... do not lay it horizontal so as to prevent the loss of clutch fluid.
3) If equipped, disconnect the air pump magnetic clutch electrical connector. Its a medium sized two wire black barrel connector located near the front of the intake manifold. Loosen the air pump pivot bolt. Loosen (backoff) the air pump upper jam nut and clamp bolt. The jam nuts (upper and lower) are 14 mm while the clamp bolt is 10 mm.
Note: The owner's manual has excellent diagrams of adjustment points for the air pump and alternator. Its a good idea to review these diagrams prior to starting the job if you are inexperienced with Jaguar drive belt adjustment mechanisms.
4) Use the pry bar to apply additional tension to the air pump belt. With tension applied, reach underneath the air pump clamp bolt and loosen the lower jam nut. With tension removed, the nut should backoff with finger pressure (unless very corroded or dirty). Spin the lower jam nut to the bottom of its travel to provide adequate air pump adjustment for removal of Vee-belt.
5) With the air pump v-belt off, remove the air pump pivot bolt / nut. No need to remove the air pump hoses, just pull the pump out of the way (towards the air filter box) and secure with a bungee cord or equivalent.
6) The air pump adjustment bolt pivot fasteners should be loosened now to allow ease of installation of the air pump after the water pump is replaced. The adjustment bolt pivot fasteners are 14 mm.
7) Raise the front end of the car and place two jack stands under the front lift points (forward side of each front door). Considerable work needs to be performed from underneath the engine bay so the car should be lifted to provide additional working room and clearance.
8) Loosen the alternator pivot bolt and nut (17 mm). Loosen (backoff) the alternator upper jam nut and clamp bolt. The jam nuts (upper and lower) are 14 mm while the clamp bolt is 10 mm.
9) Use the pry bar to apply additional tension to the alternator belt. With tension applied, reach under the alternator clamp bolt and loosen the lower jam nut. With tension removed, the nut should backoff with finger pressure (unless very corroded or dirty). Spin the lower jam nut to the bottom of its travel to provide adequate alternator adjustment for removal of multi-vee belt.
10) Remove the alternator multi-vee belt from the alternator and water pump pulleys. Position the belt near the A/C compressor to protect it and provide working room.
11) Drain the engine coolant by loosening the radiator drain plug. A large container (3 to 4 gallons) for the coolant is necessary. After the coolant has stopped draining, re-install the radiator drain plug.
12) The water pump impeller assembly has eight (8) mounting bolts. Six (6) have 10 mm heads while two (2) have 13 mm heads. Working from underneath,
remove the four (4) bolts which are visible. Two have 13 mm heads while the other two have 10 mm. One of the 13 mm bolts may not clear the water pump pulley but this is not a problem.
13) Working from the top (engine bay), remove the four (4) bolts which are visible. All of these bolts have 10 mm heads. Two of the bolts support the entire water pump assembly (impeller assembly and volute) and they have steel spacers behind the support frame. Don't drop the spacers ... easy to fall behind the crankshaft pulley. The remaining two bolts also support the air pump adjustment bolt frame. A 1/4" ratchet with short extension and 10 mm socket (if available) comes in very handy for these two bolts.
14) With all the water pump mounting bolts removed, tap the water pump hub with a suitable mallet to release the impeller assembly. At this point, there are no fasteners supporting the water pump volute ... just hoses.
15) Clean the water pump sealing surfaces on the volute to minimize the potential for leakage.
16) Before you install the new water pump impeller assembly, loosen the two (2) bolts which support the water pump support frame (located above water pump volute). They have 10 mm heads and are easy to loosen with a ratchet and socket. This step is critical in enabling the previously removed water pump-to-frame spacers to be re-installed with minimal effort.
17) Mate the new water pump impeller assembly to the water pump volute. If you previously attached the water pump gasket as mentioned, the installation is far simpler now. Finger tighten the four (4) lower water pump bolts by working from underneath. This step will locate the water pump and prevent it from falling.
18) Working from the engine bay, carefully align the two (2) spacers and finger tighten the water pump-to-frame mount bolts. Finger tighten the two (2) remaining water pump bolts with the air pump adjustment bolt frame attached.
19) Working from above and below, carefully tighten the water pump mounting bolts in a crossing sequence to prevent uneven tensioning. Ensure all eight (8) bolts are uniformly snug when finished. Don't worry about using a torque wrench for this task as it only takes a reasonable effort with small open end wrenches or a 3/8" ratchet to provide sufficient torque.
20) Re-install the alternator-water pump multi-vee belt. With the pry bar, apply tension to the belt. While tension is still applied, spin the lower adjustment bolt jam nut into place to secure the belt tension. After correct belt tension is applied, spin the upper adjustment bolt jam nut into place. Snug both nuts with 14 mm open end wrench. Secure the alternator 10 mm clamp bolt.
21) Before re-installing the air pump, tighten the two (2) water pump support frame bolts loosened in step 16.
22) Ensure the air pump adjustment bolt is through the clamp bolt frame, then re-install the air pump pivot bolt.
23) Re-install the air pump vee belt. Using a pry bar, apply tension to the belt. With tension applied, spin the lower adjustment bolt jam nut up into place to secure the belt tension. After correct belt tension is applied, spin the upper adjustment bolt jam nut into place. Snug both nuts with 14 mm open end wrench. Secure the air pump 10 mm clamp bolt and don't forget to secure the air pump adjustment bolt pivot fasteners (bolt and nut) which are 14 mm.
24) Reconnect the air pump magnetic clutch electrical connector removed in step 3.
25) Carefully lift the radiator / fan shrould & fan thermal clutch assembly and position behind the radiator. It takes two hands and some patience for this task. Slip the fan thermal clutch assembly on the water pump hub / studs. Ensure the fan shrould lower tabs mate with the frame slots. Position the shrould and install the two (2) upper spring clips.
26) Carefully install the fan thermal clutch to the water pump hub using the four (4) 13 mm nuts with locking washers. This is the most tedious sequence of the entire task. Uniformly secure the nuts using a crossing pattern from above and below.
27) Lower the front end of the vehicle. Re-fill the cooling system. Re-connect the negative side of the battery.