New Water Pump

The bearings on the water pump were a little worn, allowing a small amount of wobble on the shaft.  It seemed to be working well, with no leaks, but doubts over how long it would continue to do so, and the crippling nature of the eventual failure, made it sensible to replace the pump now before it became a problem.  Besides, I hate leaving known faults not rectified.

I got a new genuine pump from Dunsfold LR.  Replacing it was simple enough – starting with a good degreasing and cleaning of the engine, the radiator top and bottom hoses were removed, the 24V generator and the fan belt tensioner were slackened to allow removal of the three belts and then the fan and shroud were removed.  This was the hardest part, as the small screws holding the fan shroud to the rad were all rusted in.  They are shouldered, and the threaded segment is very thin and easy to shear.  A spray of penetrating oil (forget WD40 – it’s not much good at freeing up rusted fixings) made them easy to get out with no breakages or chewed heads.  the fan was very tight on the pulley and needed to be tapped off with a mallet.  the risk here is it damaging the rad as it comes off, so a few sheets of steel from my garage were laid into the radiator’s fame to protect the core.

With the fan off and shroud clear, the water pump’s seven fixing bolts were easily accessible.  These came out easily as someone (probably REME) had lubricated the bolts before fitting.   With the rad bypass hose (below the pump) disconnected and the bolts undone, the pump was removed.  With the mating face on the timing chest cleaned up with a razor blade and the new water pump’s face cleaned with degreasant, they were reassembled with a new gasket and sealant.  The bolts were given a generous amount of copper grease to ensure similar ease of work in the future.

The radiator was given a good clean and inspection at this point, followed by a thorough spraying with WD40 to protect it over winter.  The shroud and fan were cleaned and refitted, with their bolts and screws greased like the water pump bolts.

The thermostat was a little suspect, too.  The engine was running quite cool , which is to be expected with the standard MoD 74oC thermostat, but it was lower than this would explain.  The time taken to reach maximum temperature was also very long – 15-20 minutes of swift driving.  I suspect the thermostat was seized in its open position, so it was replaced with a new 74oC unit from DLR at the same time.  Again, the bolts had previously been oiled or greased, so it was a very quick and easy job.

After all this, the engine was given a bit of a tidy up with a brush application of the engine paint supplied with the Lightweight .  It isn’t a perfect job, but it was just a quick job to neaten the appearance under the bonnet.  The chassis rails got a brush of black paint too.

The original track rod was quite bent, which is the likely cause for the scrubbed shoulders on the front tyres.  This damage was probably done at the same time as the dented diff pan (it isn’t in contact with the diff and isn’t leaking, so will not be joining the “to do” list).  I saw the diff pan on the pre-purchase inspection, but hadn’t noticed the track rod.  Thankfully, I had another track rod from my 109’s 1982 axle (which was replaced with the 1972 axle during the rebuild).  the damaged rod was removed and its good rod ends swapped over to the “new” rod, whose ends were a little looser.  The rod was cleaned up and fitted, followed by careful adjustment and then painting 9the rest of the axle was given a coat, too, to cover the green over-spray from its body respray).

Finally, I replaced the oil sump temperature sender with the new one also included in the vehicle sale in an attempt to get the oil temperature gauge working, but this was unsuccessful – with both senders, the needle goes off scale as soon as the ignition is switched on, but connecting the gauge to the coolant temperature sender in the head shows more normal indications.  Clearly, the fault is in the gauge itself, but at £90+VAT for a new one (just the single gauge, not the entire cluster of three), it’ll have to wait until a second hand unit becomes available – it is an optional extra instrument fitted only to monitor the oil temperature on FFR vehicles as they were expected to have engines idling for protracted periods, which simply won’t occur in our use of it.  So, for now, the gauge is disconnected from the fuse box and unpowered. It will be repaired eventually, but is not important for now, how ever much it irritates me!