Lets say the lower hose is colasping. Maybe adding a coolant recovery system would fix this. Sounds strange right? When the hose colaspes it displaces coolant. If theres no air in the system where will it displace to? I don't think it'll go in to the recovery by over coming the cap pressure. Your thoughts.
I know this is not the right fix but it was on my mind.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

The more I think about it, it just seems dumb. This problem usaully happens at high speed driving which also provides the best cooling which in turn "shrinks" the coolant alouwing room for the hose to colaspe
Never mind

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

If there's room in the system (air, esp. with older big tank top system) the air will be compressed, so I can see the hose collapsing.


How pressurized is the system when you're not close to boiling over anyway????????????

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

the proper lower hose is supposed to have a spring in it which keeps it from collapsing. one of those ribbed "universal" hoses will work too.


good luck
tophat

No, adding a coolant recovery system would not in the slightest affect the collapsing lower hose.
Only when you squeeze it by hand. It works the other way round when the hose collapses.
The one and only correct fix, a spiral reinforcement in the lower hose, is so cheap and easy that it's not worth noodling around on anything else.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

actually when your lower hose is colapsing, it's because the pump is outflowing the rad capacity (due to restriction) or because the hose has gotten so soft and worn that the negative pressure that the pump puts in the system makes it collapse instead or drawing coolant thru it.

I'm sure there's benefits in using a recovering coolant deposit and a matching system for this, but not just fixing the lower hose problem when it becomes an issue. That hose and other "cheap" reinsurements of cooling and oiling system should be replaced much more often in order to keep an engine running good, strong and safe.

I replace my hoses every 2 year or so (especially the ones that contains coolant) and the thermostat and other stuff like that as well. Maybe someone would see me wasting money, but all my slant 6 engines have run well over 800.000 km flawlessly. Most of them averaged above 1 million km... only one of them drop dead before the 1 million km mark and that was because I installed one cheap piece of garbage under the carburetor that was supposed to improve fuel delivery and efficiency, and it did on lower engine speeds, but at high RPM the flow restiction and "economy improvement" turned out to overlean the mixture and I burnt all the 6 ex valves... in the middle of a round 5,000 km trip. I returned home with 6 dead ex valves, didn't want to leave the car and drove it back and that caused major damage to an already tired engine.

Except for that one, good filters, good oil, molikote on every oil change, new coolant every 6 months tops one year, new t-stat every time I change coolant, and more generally speaking not being cheap on the engine servicing has proven to produce excellent results IME.

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

On my /6 with overflow, I've seen my radiator hoses collapse after the car cooled down; when I investigated, I found that the vacuum relief valve in the radiator cap was gunked up and wasn't letting air in. I clean it and all was well.

The gunk appeared to be some of the Bars Leak brand stop leak added long before. I've had good experience with Bars Leak and it has caused few other problems (except when my brother-in-law dumped in ~4X the recommended amount).

You should try to never have negative (less than atmospheric) pressure in your cooling system, as it stresses components the wrong way.