Fitting an Electric Water Pump (EWP) to a XJS Jaguar - Step by Step

12/01/2015 07:22PM

One of our customers was kind enough to provide his notes for the fittment of our EWP150 to his XJS Jaguar.


I thought I would send you a couple of notes on my installation of the Davies Craig electric water pump. The installation is not that difficult, but there are a few things you will need to do for it to be effective.

  • As Davies Craig suggests below, there is a simple approach
  • As Davies Craig suggests below, there is a simple approach
  • As Davies Craig suggests below, there is a simple approach

As Davies Craig suggests below, there is a simple approach and that is to remove the impeller from the mechanical water pump but replace the bearing and instal the EWP in the bottom radiator hose. That way you can use all the existing belts where they were. However, I have done the following to get the installation as tidy as possible;

1. Remove the mechanical water pump and pull apart. Have a 90 degree 38mm spigot TIG welded to the centre of the back plate. Weld up the other two holes. You will need to source some shorter bolts. Note the water pump bolts are all different sizes! I used a loctite gasket maker which worked well as the paper gaskets are terrible. The next challenge is to find a good location for the EWP.

. Locate the EWP just behind and under the power steering pump. I sourced a coolant hose (38mm) from a Landcruiser HJ75 which bends in the right places. It will need to be cut to size so as to fit between the EWP outlet and the 90 degree input spigot on the blanking plate.

3. Next you will need to make a small piece of aluminium pipe that reduces from 44mm to 38mm with a 12mm T piece. Use a piece of the left-over 38mm Lndcruiser hose and connect between the input of the EWP and 38mm end of the short pipe.

. Cut the original JGUAR bottom coolant hose so as to fit the bottom radiator outlet (44mm) and the short pipe. Connect the 12mm outlet to the header tank. This 12mm hose originally connected between the top of the bypass pipe to the header tank which essentially is the suction line.

. I used some cable ties to keep the EWP close to the engine to ensure no movement towards the power steering belt.

. By removing the water pump you loose a belt and idler pulley. I sourced a new belt that goes between the power steering pump, crank and A/C compressor. You will need to move the compressor slightly forward to line up with the power steering pulley. This can be done with nuts acting as spacers. I also fitted an new light weight compressor making this a little easier. Adjustment for this belt is at the power steering end.

. The EWP has its own electronic controller so you don't need the thermostats. These can be removed along with the cross-over pipe.

. I fitted a new aluminium radiator which was manufactured by Race Radiators in Melbourne. This is heavy duty and super efficient. I had it manufactured as a single pass radiator with two inputs on the top right hand side. I had a new aluminium cross pipe manufactured with filler and put in place of the old cross over pipe. I sourced some right angle hoses to connect to the left thermostat outlet and lower input to radiator. The right hand thermostat housing connects to the top outlet with existing top hose. You should consider fitting Tefba coolant filters as they protect the radiator.


  1. As Davies Craig suggests below, there is a simple approach
  2. As Davies Craig suggests below, there is a simple approach
  3. As Davies Craig suggests below, there is a simple approach

. I sourced 2 x 12" High Performance Fan & Shroud Assembly . This kit fits the radiator perfectly. Davies Craig also provide fan kits and you may wish to just replace the main belt driven unit with a 16" electric.

. You will next need to install the Davies Craig thermo sender. I installed this in the right hand side thermostat housing which measures the coolant leaving the engine block before entering the radiator.

. The electric fans can be controlled by the Davies Craig electronic controller. You will need to install relays and also arrange for control from the A/C compressor.I can send you some suggested wiring if you wish.

. Be sure to instal the electronic control unit inside the car and NOT in the engine bay. I installed it in the glove box which works well.