Water Pump

[MastuhWaffles]

Well after 9 years today the water pump gave out on my truck, I saw the temperature shoot up and the red light come on so I pulled over and shut off my truck. Well I'm going to replace it tomorrow, is there anything I should know about replacing it or is it fairly straight forward?

 

[RonD]

What engine?

Need a fan clutch wrench set or good belt strap wrench and thin crescent wrench or ??

But fairly straight forward, on some water pumps the bolts are different lengths, some are obviously longer or shorter, some not so much,(Toyotas!!!) keep them in the correct order

 

[MastuhWaffles]

what engine?

Need a fan clutch wrench set or good belt strap wrench and thin crescent wrench or ??

But fairly straight forward, on some water pumps the bolts are different lengths, some are obviously longer or shorter, some not so much,(toyotas!!!) keep them in the correct order

4.0 sohc v6

I let it cool down all the way and just coasted it into the hangar to work on, still starts up fine and sounds just like normal so I don't think I did any damage to the engine.

 

[RonD]

yes, keep a good thought


Overheating is a bit like buying a lotto ticket a month ahead of time

You pay your money but won't know end results for awhile

When an engine heats up the head metal expands, as well as the block metal but not as much, and when engine is shut off metal cools down and shrinks.
So every heat up/cool down squeezes the head gasket between head and block.

When you over heat, the head metal expands even more, especially aluminum heads, this adds more pressure on the head gasket, and it can be crushed, or weakened.

You could pressure test cooling system before starting the water pump job, and it could tell you of a problem before doing that work, but it isn't definitive that no damage was done.


Which is why you "keep a good thought"

 

[MastuhWaffles]

yes, keep a good thought


Overheating is a bit like buying a lotto ticket a month ahead of time

You pay your money but won't know end results for awhile

When an engine heats up the head metal expands, as well as the block metal but not as much, and when engine is shut off metal cools down and shrinks.
So every heat up/cool down squeezes the head gasket between head and block.

When you over heat, the head metal expands even more, especially aluminum heads, this adds more pressure on the head gasket, and it can be crushed, or weakened.

You could pressure test cooling system before starting the water pump job, and it could tell you of a problem before doing that work, but it isn't definitive that no damage was done.


Which is why you "keep a good thought"

I just don't understand why it decided to crap out all of a sudden, my truck only has 70,000 miles on it.

 

[MrGiggles]

There's really not much in a water pump to fail. They'll start pissing from the weep hole, but can run for a long time like that until the bearings fail.

That being said, with a leak it won't hold pressure, and your boiling point decreases dramatically. On a hot day, it can definitely cause it to overheat.

I would sniff the coolant with a block tester just to make sure a head gasket isn't leaking, but it's probably okay.

I'd replace the thermostat while the coolant is drained as well.

BTW, you can use an air hammer and punch on the big fan nut. It may be a left hand thread as well, usually there is a decal on the core support if it is.

 

[adsm08]

Fan is not left-hand thread.

 

[MastuhWaffles]

There's really not much in a water pump to fail. They'll start pissing from the weep hole, but can run for a long time like that until the bearings fail.

That being said, with a leak it won't hold pressure, and your boiling point decreases dramatically. On a hot day, it can definitely cause it to overheat.

I would sniff the coolant with a block tester just to make sure a head gasket isn't leaking, but it's probably okay.

I'd replace the thermostat while the coolant is drained as well.

BTW, you can use an air hammer and punch on the big fan nut. It may be a left hand thread as well, usually there is a decal on the core support if it is.

It's never had an issue on a hot day before, I've driven on hotter days than this. When it overheated I let it cool down and started it up again to drive it back to the ranch, and maybe only 2 minutes the light came back on and I had to pull back over to let it cool off. The pump probably died, it also makes a high pitched whine.

 

[RonD]

With a 4.0l SOHC I would change thermostat if it was overheated, and check around the housing for current or past coolant leaks, stains.

Good read here on that: http://bengrosser.com/howto/fordthermostat/


So if you loosen and remove fan belt from water pump and then spin the water pump it makes a noise?

But no coolant is leaking out the underside of the pump?

No coolant leaking would be unusual, weep hole on the underside of the pump is there to help ID a failed or failing pump, if impeller starts to go it causes a wobble that breaks the seal and coolant starts to leak out, or if bearing starts to go it causes a wobble and seal starts leaking.
So when a water pump fails it always leaks, certainly possible for electrolysis to eat away at the impeller blades until it simply can't circulate enough coolant, but that wouldn't be sudden, I would expect warmer and warmer operating temps over a few weeks and months

 

[MastuhWaffles]

With a 4.0l SOHC I would change thermostat if it was overheated, and check around the housing for current or past coolant leaks, stains.

Good read here on that: http://bengrosser.com/howto/fordthermostat/


So if you loosen and remove fan belt from water pump and then spin the water pump it makes a noise?

But no coolant is leaking out the underside of the pump?

No coolant leaking would be unusual, weep hole on the underside of the pump is there to help ID a failed or failing pump, if impeller starts to go it causes a wobble that breaks the seal and coolant starts to leak out, or if bearing starts to go it causes a wobble and seal starts leaking.
So when a water pump fails it always leaks, certainly possible for electrolysis to eat away at the impeller blades until it simply can't circulate enough coolant, but that wouldn't be sudden, I would expect warmer and warmer operating temps over a few weeks and months

Well I didn't have much time to look at it, but tomorrow I'm going to investigate and see whats all going on. There was coolant everywhere from it coming out the pressure relief valve but I didn't see any definitive leaks or such.

 

[RonD]

Coolant would come out of the overflow tank, when engine started to over heat.

So any bubbling over would tend to be on the passenger side of engine bay.

If it is "everywhere" then a hose probably cracked and started spraying out coolant, that could have been the cause of the overheating or the result as pressure in the system got higher than normal

 

[MastuhWaffles]

So problem has been found. My dad came up and we went about trying to see what happened. Well upon starting the engine and adding some coolant to the radiator since it all leaked out we found out that the thermostat and the thermostat housing pretty much exploded. And I literally mean exploded because they both were in chunks and coolant was spraying out of the housing. About $70 bucks and 2 hours later with a trip to Whataburger we had the new thermostat and housing in place which was an interesting job. Drained all the old coolant out and filled up with some new stuff. (Was on sale for the 4th specials.) And slapped on a new belt, the old one is in good condition but its at 70,000 miles so might as well. Did some testing and drove around for awhile on the road and highway and it stays below the halfway point on the gauge so fingers crossed its fixed.
Water pump was not the issue, you guys were right.

 

[RonD]

Good work

Thanks for the follow post and fix

Leaking/cracked thermostat housing on the 4.0l SOHC is not uncommon, but first time I read about it disintegrating

 

[MastuhWaffles]

Good work

Thanks for the follow post and fix

Leaking/cracked thermostat housing on the 4.0l SOHC is not uncommon, but first time I read about it denigrating

I'll take some picture of it later.