How hard is it to change the water pump?. 2000 Land Rover Discovery. Also need a serpentine Belt. Or should I just let a Mechanic do it?

 

Very easy. Just look at the Rave manual and follow that. You should be able to do it in maybe 2 hours tops. The only that that is tough the 1st time around is getting the fan off. Other than that you just need to take out the bolts (keep track of which is which), scrape off the gasket carefully and clean the surface, and put the new one on. Since you are draining the system anyway, it is a good time to flush out the coolant system and maybe throw a new t-stat in as well (but test it first).

 

Will look like this, D1 = D2 water pump. When they get high miles, the pump wobbles and leaks. Wobble = eat aluminum. Fan comes off by restricting movement of fan belt, wrench on fan bolt of the water pump, and hit wrench hard and sharp, toward the passenger side (on a NAS vehicle).

 

We bought our 2003 in July last year and did all the high miles service in hopes of not having to do any repairs in the winter.

As of November we have replaced the Viscous Fan, Crank Position Sensor and we are now also looking at the water pump. All in cold miserable weather.

The weekend's forecast to be 28 degrees Fahrenheit and we will doing the water pump and our garage will not fit the Discovery.

Our water pump is seeping coolant through the weep hole (coolant expansion tank has remained full and have NOT had to top off) as we can see coolant on the ledge right below the pump and on the the weep hole. We also have the A/C condenser fan is coming on during city driving (Hawkeye shows 98 degrees Celsius). After reading RAVE multiple times, I can not fathom any reason for the condenser fan coming on in the winter with below freezing weather.

We do not want take any chance of losing the pump/ coolant and have a head gasket job (truck has the original head gaskets) so off with the water pump. We are also going to replace the upper radiator hose as the bleed screw has been damp with spot of coolant and I dare not tighten it any more than a 1/4 turn past tight.

My guess why the pump went bad is the new load put on the pump bearings when the Viscous Fan was replaced. The old fan freewheeled but now the new fan puts a load on the water pump bearings. I have read a number of posts on this forums and others to replace the water pump when you replace the fan if you do not have the service history. We did not have a record of the pump replacement from the previous owner so we should have followed the rule.

We bought the brass impeller water pump per Disco Mike's post and the pump carries a two year warranty.

2003 Discover 124 K with high miles service completed

 

The fan is set to come on if coolant reaches 212F, so you are close. It would turn off at 202F. From RAVE in workshop manual:



(212 °F)

You are correct than many times the pump and the fan clutch hold hands as they jump off the cliff....

If you have hose off to the thermostat inspect for any of the little holes in the top leg being clogged.

Be sure you end up with belt route correct, cupped side of blades toward engine, all radiators and condensers free of mud clogging the fins, trash, etc.

 

Replacing the thermostat and coolant was the first service we did when purchased the vehicle and I will be sure to closely inspect those holes in the thermostat again when we change the upper hose.

In the spring our preemptive service will be replace the radiator (going to also replace the high pressure steering line as the line looks really rusty) and lower/ remaining coolant hoses. This weekend job is the water pump and upper hose because of snow on the ground and cold, I just do not have the motivation to lay in the snow/ spend time outdoors fooling around with the lower hoses. I am sure the plastic parts in cold weather are as brittle as an icicle.

The upper hose will be replace as I can bet money the bleed screw or housing will break when we go to bleed the coolant.

I agree with the RAVE technical data but with the weather being below 30 degrees Fahrenheit and not running the A/C the engine has to be getting hot for the condenser fan. My guess is the pump is tired or wearing against its housing and the pump is certainly seeping coolant. As a side note - the condenser fan was also our first clue about the Viscous Fan being bad in back in early December.

I am so glad we fixed the condenser fan when we bought the truck as the fan has been our canary in the coal mine.

2003 Discovery 124 K with high miles service complete