why would the water pump leak coolant here...

Post by **xHeart** » 02 Aug 2012, 15:06

In past two weeks i have focused on replacing the water pump, but why is it leaking here? There is no discussion on MVS of this location. Are there many designs of water pump for 850 model?

: location of seep; MVS_0193a.jpg (338.64 KiB) Viewed 1585 times

: a trail of coolant; MVS_0172a.jpg (297.96 KiB) Viewed 1585 times

: at the lower corner of TB cover; MVS_0164a.jpg (278.28 KiB) Viewed 1585 times

It look different.

Post by **rspi** » 02 Aug 2012, 15:57

How old is that pump? It looks pretty new.

I doubt that is the point of the leak. There is a lot of wind in the cover area due to the belt, cams, etc. spinning around. It will blow coolant all over the place. Try to snug/torque the bolts down again if the pump was installed within the past few months.

Post by **jimmy57** » 02 Aug 2012, 16:56

The "white" engine have no freeze plugs. The pump has one to be a little bit of protection for freezing. Volvos are sold and operated in places where even with coolant protection from freezing, the freeze point depression may not be enough and freezing coolant would result.
Porous aluminum castings are a part of use of aluminum. I have not seen a water pump leak at that freeze plug but for it to leak there would not surprise me.
Unfortunately it will require removal to repair. If you remove it you might as well replace it. If it a galled area where the side of plug was pressed it then removing and applying a sealant and pressing it in again should fix it. If it is porosity in the casting then sealing it would be "iffy".

Post by **xHeart** » 02 Aug 2012, 20:59

rspi wrote:How old is that pump? It looks pretty new.

I doubt that is the point of the leak. There is a lot of wind in the cover area due to the belt, cams, etc. spinning around. It will blow coolant all over the place. Try to snug/torque the bolts down again if the pump was installed within the past few months.

Pump was replaced at the time of timing belt, October 2010, says the copy of service record. I am preparing to take down the timing belt, and replace the pump with the hope to not do this again for a while. Which pump maker, Aisin is OEM.

jimmy57 wrote:The "white" engine have no freeze plugs. The pump has one to be a little bit of protection for freezing. Volvos are sold and operated in places where even with coolant protection from freezing, the freeze point depression may not be enough and freezing coolant would result.
Porous aluminum castings are a part of use of aluminum. I have not seen a water pump leak at that freeze plug but for it to leak there would not surprise me.
Unfortunately it will require removal to repair. If you remove it you might as well replace it. If it a galled area where the side of plug was pressed it then removing and applying a sealant and pressing it in again should fix it. If it is porosity in the casting then sealing it would be "iffy".

Freeze Plug - Is this element new in water pump design? I did not see it in MVS posts from few years ago.

I had replaced the leaking original radiator with Volvo's with the MVS help few weeks ago. Now my to-do list for heating and cooling before winter includes, replacing thermostat, bleeder hose, water pump, and switch to Prestone mixed with distilled water. Are there other repairs i am missing that would help prevent early failure?

Not drive! :lol:

It runs great!