Water pump replacement & cooling system checklist

[Polara 500]

I always appreciate reading the informed feedback from this site. Question regarding cooling system maintenance... while replacing coolant, thermostat, water pump and hoses, would you go ahead and remove the water pump housing and replace those gaskets while you're most of the way there?
I'm trying to get the cooling system back up to par on my 66 Polara (383), as after never having the temp gauge exceed 180 for 4-5 years, even in hot summer traffic in Atlanta, it began to get hot this past year. After noticing a slow leak and realizing that I had neglected to change the coolant for about 5 years, I knew it was time to drain, flush, fill, etc. So I drained it, flushed it, etc. but before I was ready to add new coolant I noticed water draining from front of engine. So here's my plan so far:
- Have new thermostat ready to replace.
- New upper and lower hoses (at least 5 years old).
- Replace water pump.
- Scraped old gasket material off.

Any further advice is much appreciated. Photos show what old stuff looks like when I removed them today.
Thanks!

 

[Big_John]

would you go ahead and remove the water pump housing and replace those gaskets while you're most of the way there?

Not unless it was leaking.

Basically, if it's not broke, don't fix it.

 

[Omni]

...I noticed water draining from front of engine.

Is the coolant leakage from the water pump weep hole?
If so the pump may be telling you that it is time for a change.
Omni

 

[CBODY67]

IF you want to replace the pump as an investment in not having to worry about it again and with no knowledge of how long it has already been there . . . just to make sure and then have a new baseline time to deal with, changing it while there can be an option.

The other thing, according to "old wives", is that antifreeze will leak where plain water will not.

A side issue can be that with the deteriorated cooling performance of late, it could be that the water passages in the cyl block are getting "accumulations" in them. Knocking out the core plugs and flushing the block out that way, messy as it is, might be needed. Such accumulations "settle out" in the lowest spot in the system, one of which is the back of the block. Another "investment".

IF the radiator is getting accumulations in it, too, that can affect the performance of the fan clutch. How? The fan clutch locks-up when the thermostat on it "sees" heat higher than a certain temperature. If the radiator is clogged with decreased flow, then "no heat" in that area, so the fan clutch thinks it's not needed . . . as the temp gauge indicates otherwise.

If the existing fan clutch is still "tight", re-use it. You can also get a Phillips head larger screwdriver, a hammer, and dimple the front of the fan clutch, on each side. That will increase the internal pressure of the fluid in the clutch a bit, so it'll be harder for it to freewheel or unlock. Might extend the life of your clutch, too.

Just some thoughts,
CBODY67

 

[Polara 500]

Not unless it was leaking.

Basically, if it's not broke, don't fix it.

I appreciate that! Thanks

 

[Polara 500]

Is the coolant leakage from the water pump weep hole?
If so the pump may be telling you that it is time for a change.
Omni

Yes it was, and I'm definitely putting in a new one. Thanks

 

[Polara 500]

IF you want to replace the pump as an investment in not having to worry about it again and with no knowledge of how long it has already been there . . . just to make sure and then have a new baseline time to deal with, changing it while there can be an option.

The other thing, according to "old wives", is that antifreeze will leak where plain water will not.

A side issue can be that with the deteriorated cooling performance of late, it could be that the water passages in the cyl block are getting "accumulations" in them. Knocking out the core plugs and flushing the block out that way, messy as it is, might be needed. Such accumulations "settle out" in the lowest spot in the system, one of which is the back of the block. Another "investment".

IF the radiator is getting accumulations in it, too, that can affect the performance of the fan clutch. How? The fan clutch locks-up when the thermostat on it "sees" heat higher than a certain temperature. If the radiator is clogged with decreased flow, then "no heat" in that area, so the fan clutch thinks it's not needed . . . as the temp gauge indicates otherwise.

If the existing fan clutch is still "tight", re-use it. You can also get a Phillips head larger screwdriver, a hammer, and dimple the front of the fan clutch, on each side. That will increase the internal pressure of the fluid in the clutch a bit, so it'll be harder for it to freewheel or unlock. Might extend the life of your clutch, too.

Just some thoughts,
CBODY67

Thanks CBODY67, I had a friend ask me about the core plugs as well. I'm going to hold off on that for now but definitely replacing the pump. Radiator and fan seem fine, but will definitely keep your comments on hand if that changes. Thanks

 

[MoPar~Man]

I've come across mention that measuring the voltage between the coolant and the radiator or body ground is an indication of electrolysis and the condition of the coolant. It would have been interesting to know what your reading would have been before you took the cooling system apart. Also a Ph reading.

Technical notes of interest to Marine Engineers