[sobieski]

Replaced my expansion tank cap with a brand new one and now when the vehicle cools down, my top radiator hoses suction flat.

Could the cap be defective?

I also have a water pump leak and planned on replacing today too.





-sobieski

 

[gurunutkins]

If the cap is the only thing changed then yes it could be defective - did you get a good brand name?
the water flow is shown below and in theory so long as air can enter the system through the breather tube in the neck of the extension tank /cap seal area - then there should be no way the pipe can collapse unless the thermostat is plugged closed (not just closed because then the bottom channel is open).
Make sure the bottom hose out of the expansion tank into the engine (thermostat out line) is not kinked too.
cheers
Barri

 

[tyl604]

What am I missing in the diagram? Cannot figure out where the water comes out of the water pump. The drawing just shows water going into the water pump.

 

[gurunutkins]

The water goes out of the back of the pump through the 2 "ears" straight into the block.

 

[sobieski]

Whats the best way to get the old water pump gasket off??
It's "glued" on.


-sobieski

 

[sobieski]

Before

Then this

After

-sobieski

 

[gurunutkins]

That looks good - just make sure the surface is still flat before you re-install the new pump. Use a piece of glass and some marker dye (like prussian blue) or similar. Dont use any glue! the gasket may come with heat sealer on the outer side towards the new pump but nothing on the engine side. If you are really desperate to use something use hylomar or reinzosil. They remain supple and will peel off when you remove the gasket.
cheers
Barri

 

[sobieski]

Put the "old" coolant reservoir cap on and no more crushed top hose.
The "new" cap was brand spanking new - not sure why it would vacuum the coolant hoses as the engine cools down.
Any ideas would be great, before I go buy another cap (the "old" one has damage at the very bottom).
Thanks.