1990 XJ-S Coupe (US Spec, 5.3L V12)




9/16” Open End Wrench



There are four belts in the front of the engine – one for the Engine Cooling Fan, one for the Power Steering Pump/Water Pump, one for the Air Injection Pump/Air Conditioner Compressor, and one for the Alternator.  They come off in that order.


While apparently you do not have to, removing the Engine Cooling Fan makes things easier – see that page for the Engine Cooling Fan Belt removal.


Raise the front of the car with a Jack/Stands.


To remove the Power Steering Pump/Water Pump Belt, first take the outer left-side Air Filter Housing off to get a better shot at loosening the Power Steering Pump adjustment nuts.  The XJ-S Service Manual Volume 3 Section 57.20.02 describes how to change this belt.  Loosen the Belt Tension Adjustment Nut closest to the engine with a 9/16” open-end wrench – loosen it all the way.  Then loosen the Power Steering Pump Pivot Bolt at the rear-bottom of the pump – I did this from underneath the car.  Now the pump should be able to pivot towards the engine – if it seems tough, tighten the Belt Tension Adjustment Nut furthest from the engine – that’ll pull the pump inwards.  Unplug the wires going to the Auxiliary Fan Thermal Switch, and take the belt out.


Loosening the Power Steering Pump Belt

(Viewed from Left Side)





Next is the Air Injection Pump/Air Conditioner Compressor Belt.  The XJ-S Service Manual Volume 4 Section 86.10.03 describes how to change this belt…


     Air Pump/AC Compressor Belt Removal

(Viewed from Right Side)


Loosen the Air Pump Belt Adjustment Nut closest to the Pump using the 9/16” wrench.  I could not see a pivot bolt, so I just used a bar to leverage against the pump/car body and move the pump toward the engine.


You could also tighten the Adjustment Nut closest to the engine to pull the pump inwards.  Remove the belt.  (I have taken this belt off the pulleys numerous times by unbolting the Air Compressor).


Finally, remove the alternator belt.  This is done from underneath (hence raising the car).  Using a 9/16” open-end wrench, loosen both adjustment nuts, and then loosen the one closest to the alternator as much as you can, letting you pull the alternator in and loosening the belt enough to get it off.


Alternator Adjustment Nuts

(Viewed from Top-Front of Engine – Front of Car Toward Bottom of Photo)











I got my new belts from (their part number IN100974) for $22.44.  Put the new belts on in reverse order.


  1. The Alternator Belt should be tightened so you get 0.17 inches of deflection when putting a 3.3 lb load on the belt’s midpoint (XJ-S Service Manual Volume 4 Section 86.10.03).


  1. The Air Pump/AC Compressor Belt should deflect 0.22 inches when putting a 6.4 lb load on the belt approximately 2” away from the Air Pump Pulley (Volume 2 Section 17.25.17).


  1. The Power Steering/Water Pump belt should deflect 0.16 inches with a 6.5 lb load midpoint (Volume Section 57.20.02).


  1. The Fan Belt should deflect 0.17 inches with a 6.4 lb load at the mid point (Volume 2 Section 26.20.07). 


Good luck with that – I tightened them so they would deflect about a ¼” when I get them a push.  Next project…