Best coolant for a 307 ?

Roy Ale

New member
Oct 20, 2020
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Victoria BC
What is the best coolant for a 1982 307 engine ? one site says the 307 needs the old style 2 year green coolant as it has better lubricant for the water pump . The older green coolant is not that common any more . I now have the 5 year long life Prestone in the 307 . Just put it in as the water pump had to be changed . The water pump was not leaking but bearings were grinding and loose . So now i am wondering did the water pump fail do to having the wrong coolant in engine . Last water pump had only about 9000 k on it , but car was in storage most of that time. And was a reman pump . Should i put in an additive to increase lubricant ?
 
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Olds 307 and 403

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Oct 4, 2018
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Melville, Saskatchewan
You could add water pump lubricant, it should not hurt. I have been using the universal coolant in Olds V8's for a few years with no issues.
 

Bill Demmer

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Oct 12, 2018
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Planet Earth, Milky Way Galaxy
Your W.P. bearings are totally sealed against the coolant in the system. The type pf coolant you use has no bearing on the bearings. Use the long-life coolant, and add the appropriate amount of W.P. lubricant. W.P. lubricant is for the seal. It also contains anit-rust and corrosion inhibitors. If you can afford a new ACDelco pump, I'd use it. I've had nothing but trouble with reman'd/off-brand W.P.s. Set your belt tension with the proper belt tension gauge-your bearings will thank you.

Bill
 

Olds 307 and 403

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Oct 4, 2018
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Melville, Saskatchewan
Bill good advice, where does one get a belt deflection gauge? I wish any water pumps besides Flowkooler had a closed impeller like the factory heavy duty cooling models. I am surprised anything A/C Delco is worth the extra money. Almost anything from them is Made in Mexico or China and not premium quality like it used to be.
 

Roy Ale

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Thread starter
Oct 20, 2020
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Victoria BC
I had a shop replace the water pump . The new pump is an ASC WP-455. Any input about this Water pump ?

Belt tension. The shop uses a belt tension gauge. they get the belts very tight , seems way to tight to me ! when i adjust the three belts i do not get them that tight. Could my loose belt tension adjustment have anything to do with WP bearing failure ? I would think to tight would cause bearing failure .
 

Olds 307 and 403

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Oct 4, 2018
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Melville, Saskatchewan
Too tight causes bearing failures. The ASC stuff seems to be good quality.
 

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