There is no set time or mileage. It should be replaced when it leaks or becomes noisy or ALWAYS when replacing the timing belt. You should consider them to be a set, when one needs changed, so does the other. They are cheap compared to the labor expense of changing them. The water pump is powered by the timing belt and takes just an extra few minutes to change when doing the timing belt. I speak from experience since I had to pay for the job twice when the water pump of my '96 Outback went bad within weeks of replacing the timing belt. Good luck! --Ken
probably water intrusion in your switch assy.
This may sound like a smart-alec answer, but I am serious. Take your Forester to the auto parts store. Tell them you want the blades replaced. They will do it for you for the cost of the blades. No extra charge, at least in my experience. I changed my own timing belt and water pump, but the wipers I leave to the experts! -Ken
What are the symptoms that you are trying to fix? I asked a similar question and the answer eventually became "head gasket".
I recently replaced the water pump on my 2000, and they should be the same. The water pump is driven by the timing belt and you replace them both at the same time. Only down side, and it's a BIG down side, is that you have to remove the front engine pulley that is attached with a bolt torqued to 135 foot-pounds. There is a special tool (we made one) necessary to hold this pulley still so that you can loosen the bolt. Normal hand tools that you may have will not do the job. I would recommend taking your Forester to someone who has done the job before. --Ken
Did you give the dealer a price limit? Most people would change both, but if you told him, "don't go over x" and changing the water pump would do that, he had no choice but to not change it.
Water pump and timing belt should be replaced at the same time since the labor is essentially the same. Both need to be replaced at 10 years or 100,000 miles. In my opinion it is not a job for a first timer since it involves removing everything at the front of the engine. If you want to give it a go, purchase a Subaru service manual available from eBay sellers for around $10. You will then have detailed instructions to decide whether you have the skill and tools to do the job.
Head gasket is leaking
Water pump is on the left front of the engine, being driven by the timing belt. Since you cannot see the timing belt when the engine is fully assembled you also cannot see the water pump. You did not ask, but I always recommend renewing both at the same time.
The evaporated water is replaced by the added water.
The Thermostat is located in the bottom of the water pump. Under the front end on the driver's side, there is a radiator hose running to the corner of the engine. The point where the hose enter the engine is the thermostat housing. It is held on by two bolts.
The Oldsmobile AleroThe vehicle that replaced the Achieva was Oldsmobile Alero (produced from 1999-2004).
Likely a head gasket issue, especially if this is a 2.5L DOHC. The head gaskets on the 1998 Phase 1 Subaru 2.5L DOHC engines have a high failure rate.