Help! 302 overheating

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#16

06-04-2016 | 02:01 AM

No704

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Joined: Nov 2015

Posts: 68

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From: Tempe, AZ

Quote:

Originally Posted by grandpas1974

Forgive my ignorance, but I'm assuming an overflow tank is the same thing??? No, the truck doesn't have one. I have considered it, and with the symptoms i'm seeing I still may give it a try even though that shouldn't be the reason I'm having overheating issues I wouldn't think. Most people on the forums agree they are not needed, but it's cheap and a no harm no foul addition. A senior member (maybe HIO....) had referenced JEGS recirculating cans on a thread a while back. I may look into that, although if I remeber correctly it required a specific type of radiator cap.

This weekend I plan on replacing the radiator cap and checking for any signs of antifreeze evaporate. I'm going to try to burp the system of any air and fill the radiator back up with coolant. I figure start small and work my way through the possibilities. I've been using an approx. 70/30 mix of antifreeze and water as suggested in the service manual. Is this what others are doing??? Or should I be using a different ratio???

If you have a nipple off the neck on your radiator by the cap put a length of hose on it running to a bottle. Run the hose to the bottom of the bottle this will let the coolant be able to flow back into the engine as the temp drops. I have had good results using a miller hl 40 oz
Good luck!

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#17

06-10-2016 | 09:36 AM

grandpas1974

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Joined: Jun 2013

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So I ordered a new lower radiator hose and internal spring from NPD, it arrived yesterday. Since I have to drain the radiator anyway and I'm not sure how my father installed the new radiator a little over a year ago I'm going to go ahead and flush it this weekend. While i'm at it I figure I will go ahead and replace the thermostat and water neck since they are pretty cheap. I'm planning on going with a 195 stant thermostat (P/N 45359), which I believe is stock temp ('74 302 2bbl). It gets pretty warm here in FL in the summer and winters are mild, is there any reason I should opt for a 180 instead given the described issues???

Also, the water neck (Mr. Gasket P/N 2662) comes with an O-ring seal so I don't know if I ALSO need the paper type water outlet gasket (Fel-Pro P/N 35067) or not? Anybody know?? These parts are all available at the local Advance Auto.

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#18

06-10-2016 | 11:12 AM

Tedster9

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Joined: Apr 2002

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From: Waterloo, Iowa

A 180 should be fine. There should be a couple pipe fittings on each side of the block, above the oil pan line, down low. Remove these. Use an ice pick or something to punch through the accumulated rust and scale and flush till it runs clear.

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#19

06-10-2016 | 11:32 AM

grandpas1974

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Quote:

Originally Posted by Tedster9

Stupid question, but do I leave both upper and lower hoses connected for the flush so water flushes through the engine block?? Or disconnect them and flush water directly into the water neck? Thanks for your help, never flushed the cooling system before.

Also, whats the best thread sealer to use on the plugs when re-installing in the engine block? Standard teflon be ok?

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#20

06-10-2016 | 02:51 PM

Tedster9

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Joined: Apr 2002

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From: Waterloo, Iowa

I'd try and direct everything through the top/hose and try and get strong flow through the openings. Maybe do those first. They aren't normally part of a flush but if the engine hasn't been opened in a while (ever) it will have a LOT of crud. Pipe dope would work best for sealant, I think.

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