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Discussion Starter #1
Problem...rock hard hoses, feels like theres way too much pressure in them even after its shut off
Anyone source the stock cap from a NAPA? Cant remember the lb rating, vented or non etc

sbc with 80 miles on it....shes been sitting for a long time and plan on dailying it.
Will a recovery tank change the gype of cap it needs?

When I pull the plugs out I want to pressurize the system and make sure theres no head gasket leakage.

Random thought..coolant seems to be moving awfully fast, need to take a measurement on the pulley has a high flow pump also.
Worried about combustion gases not sure the rest matters or not?
 

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1964 Chevrolet Chevelle Malibu 4 door
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14-16lbs is what I use, make sure your recovery tank / drain / blowby hose is free of restriction, might have had something building a home in it.

If your 67 is like my 64 get a plain jane cap, I tried using one with pressure relief built into the cap and the lever hit the hood, wouldn't close 100%.
 

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I use a Overflow / Recovery Tank on my 67's Rad with a Prestone RR-31 Cap
hardly ever Overflows into Tank and when it does it Sucks back into the Rad when it has Cooled Down
I know this as the Clear See Thru Plastic Tube I have on it shows it doing so

705050



705051


The Clear See Thru Tube goes to the Bottom of the Overflow / Recovery 1 Quart Tank
705052


The Black Rubber Tube on Top is for if the 1 Quart gets too Full then any over can go onto the Ground
JAZ Products 602-025-01: Recovery Catch Tank 1-Quart Black | JEGS
 

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Guy at Napa asked do I have an open/closed system, vented cap or not?
I use a recovery tank fwiw
The recovery tank uses a closed system vented cap. A 'Vented' cap = 'Closed' cap 鈥 'Vented' means is sucks from the ZERO PRESSURE tank as it cools down. 'Closed' means it does not go to the ground. A 'Non-Vented' cap = 'Open' cap- 'Non-vented' means it does not suck coolant back into the cooling system.

A cap in the 15-16 psi range would be good for your car.
 

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Discussion Starter #6
ok think i got the right cap then its a 15 lber.
Little nervouis about testing this sytem. Acted fine til (few yrs back) I ran someone clear til redline in 4th..hope I didnt crack a block . Its way abnormal.
The HV pump and pulley which may be too small moves water too quick. That couldnt contribut to it or it could?
Need to slow it down some, Ill get a stock rate pump on there.

Friend is mailing his tester for the rad and cap that will tell the story., Hope this thing isnt hurt thats all.
 

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The radiator hoses are supposed to be hard and very hot to the touch when the engine is warmed up. It is not a good determination of whether the system is working or not. If your running an auxiliary coolant tank a lower pressure cap is preferred. A 12# cap and 50/50 antifreeze puts the boiling point at around 260*.
 

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When I pull the plugs out I want to pressurize the system and make sure theres no head gasket leakage.
That same pressure testor can test the cap. Mine wouldnt open even at 25 lbs. Picked up a proper resto one that pops at 17 like it should.( non vented, but overflow is simply that) ALSO, that same testor showed me a head leak, which by the grace of God was in a cavity and leaking externally out onto a header. Finally saw it weep with 25+ psi in the system. Easy fix.

Test the caps.
 

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Discussion Starter #9
Thats what Im worried about is a HG leak. Doesnt even have 100 mi on it, never got warm.
Friend mailed me a tester should be here in a day or two.
Sure hope its just a cap but tried a few and the problem still exists.
 
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