Well I've replaced my radiator and there are NEW cooling system problems! I was planning to do the thermostat, just need to track down a long torque-wrench and an hour or two of free time, but in the meantime I noticed the occasional warm running condition transformed into all-around overheating. Checked the coolant level, GONE. No coolant. What???? I re-filled it and after about 10 minutes of running it seems to be leaking from somewhere under the engine just behind and below the fan. Is this where the water pump is located? What could it be?

Thank you much. Maybe one day I'll get the whole system sorted. That day is not today.

 

Yes - that is the water pump to the rear of the fan. More than likely the seal between the water pump and the head has failed. May need a new water pump (or even more). Has the car been overheated recently?

 

In the course of me driving it and experiencing new coolant-leak problems-- air locks, my radiator blowing, this new problem-- it has overheated a few times, but never into the red.

I noticed this morning the reservoir was empty again, big pool of water under the car. I filled it again with water, and drove 3 miles to work. The temp gauge stayed at 1/4 the entire way, very low, and drove fine. I guess it leaks intermittently? I'll drive it some more, but maybe it only leaks when the car warms up? That worries me about warped metal.

I guess I have no choice but replace the pump and hope it's not warped metal causing a leak, right? I also read somewhere about a "pump vent seal" that can go bad. Could that be what I'm experiencing as well? Is that also a "replace the pump" thing?

 

the pump needs replacing if and only if its either leaking profusely around the shaft seal, or the impellers are broken and its not pumping water.

as act1292 suggests, the little donut seal between the pump and the head directly above the pump is the commonest failure, in this case, coolant puddles on the pump in the recesses. here's one freshly installed (the water pump is the shiny silver piece)



so if you see coolant on TOP of that shiny visible part, then its that seal above the pump. aftermarket seals suck, use a real volvo one, its cheap.

another big cause of coolant leakage is the heater hoses... These are relatively small hoses between the back of the engine and the firewall. they are hard to get to, so oft neglected.

 

The leak seems to be coming from below that area. I can't observe any leakage on the top of the water pump. Does that mean the heater hose? Is this something I can fix myself? I suppose it could still be the pump itself?

 

ok, it could be leaking from the shaft, which is behind that pulley with the two belts in my picture, or it could be leaking from that big hose, which is the radiator return hose, or it could be leaking from where the pump is mounted on the block. I'd clean it off with a garden hose, let it dry thoroughly (in the sun, or whatever), then start the car and watch for leaks. an inspection mirror might help you look behind that pulley to see if its coming from the shaft, but watch out for the fan and belts!

there's also a little 'weep hole' on the bottom of the shaft part of the water pump. they are designed so it starts dripping long before the seal completely fails, lets you know it will be water pump time in the next few years.

if you DO need a new water pump, I *highly* recommend getting a real volvo one, the aftermarket stuff is mostly pure unadulterated chinese JUNK. Tasca Parts | Lowest Prices Anywhere for Genuine OEM Parts or Volvo Parts - Authentic OEM Volvo Parts direct from Volvo Parts Webstore | VolvoPartsWebstore.com are both discounting Volvo dealers.

the pump kit is Volvo PN 271975, and includes not only the pump itself, but the gasket against the engine block, and the seal against the port on the bottom of the head.

 

Hello,

Upon further observation it appears to be leaking from the area indicated by the red on the photo below. I even see some rubber sticking out, so some kind of seal there must be busted. You mentioned above that this is a particular seal that should be replaced with genuine Volvo parts. what's the seal called?

It doesn't seem to leak THAT badly for around-town driving. I just have to carry some jugs of water with me, maybe top off 1/4 gallon every time I drive it. At the very least I'm ensuring a VERY clean, fresh cooling system . My Haynes manual doesn't really explain anything about how to fix this issue, it only describes how to remove the water pump, hah.

 

thats the top gasket I previously mentioned, goes between the top port on the pump and hte bottom of the head.

part # 8 in this drawing.



you probably also need to replace gasket 2 when you remove the pump to replace this.

this is one of the places where aftermarket seals are notorious for failing. use only genuine Volvo seals.

Volvo Water Pump (940 740 760 780 240 244 245) - OE Volvo 271975OE | FCP Euro

 

this is VERY helpful... especially the schematic.

Should I go ahead and just replace the whole pump or just the seals? Thanks.

 

gasket #2 and sealing rings #7 and #8 here,
Cooling system B230F. Fits: Volvo | VolvoPartsWebstore.com

 

I picked up a set of water pump seals from my local independent volvo shop and got to work on the car yesterday. Figuring out how everything came apart was a pain in the ***-- particularly figuring out the belt tensioner system for the first time-- but I figured it out eventually.

The trickiest part about installing the new pump to block gasket was how and how much exactly to push the pump up against that round seal so that the gasket/pump holes would line up with the mounting bolts on the block. Hopefully in my searching around with the mounting bolt I didn't scrape up the gasket and screw up my seal. Unfortunately my ancient lower radiator hose was too brittle to re-use so I'm picking up a new one this morning, then I can test it for certain and see if any leak persists. It's not leaking from the upper seal, or the return hose as far as I can tell, only possible leaking point would be if I damaged the main pump gasket in my struggles to mount the pump back onto the block.

We will see!

Project was kind of a four-hour PITA for a first-timer-- my haynes manual is kinda vague on a lot of things. But if I had to do it all again now, it would be very simple.