Interesting experience yesterday: Driving along the highway about 60 mph, I heard a ‘clunk’, like I’d run over some unseen road debris.  Then, I noticed droplets on the windshield, though it was sunny. Didn’t think much about it, since farmers here are careless with their irrigation systems, and frequently let them spew water onto the road, even major highways (people in convertibles driving at night could certainly attest). But, the droplets didn’t evaporate as expected, and got even worse.  Then I realized the hood was covered also, and turning on the wipers just smeared the windshield. Finally glanced at the temp gauge (needle on ‘H’), and pulled over.  Found a split in the lower hose, right where the front mount is only 1/2 inch away.  Hoses WERE overdue for replacement, but what I can’t figure, is the ‘clunk’ sound I heard. My coolant system runs with zero pressure (modified cap) due to a leaky head gasket, so the hose failure shouldn’t likely have been so audible (?). Another mystery is why the escaping coolant was coming up over the hood at speed. Go figure.

6 VOLTS/POS. GRD. NW INDIANA

Could you have had a slug of water hit the fan?

  Dennis in Lititz PA

In all probability, the fan was slinging water all over the place.  The clunk may be unrelated to the broken hose - like running over a manhole cover


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Mmmmm….could be.  Initial release of coolant concurrent with hose failure?  Fan is 6-blade/clutch type, though not sure how that’s relevant.  Lighter-weight blades might be more flexible/resonant, especially if the initial coolant slug caused some bending/mechanical contact (I have a fiberglass lower shroud also). .  Main concern is why the hose split was adjacent to the very near edge of the front mount.  I wonder if there is enough engine rocking/twisting torque to rub against it under hard acceleration (?). I’ll likely paint that edge with something (suggestions?) and see whether it transfers to the new hose. Still a mystery to me why coolant under neg. (?) pressure (being sucked up by the water pump from an unpressurized radiator) leaking out in front of the fan’s air blast would start coming up over the fenders/hood at 60 mph. Must be some very squirrelly air currents in the engine compartment of a ‘55 Bird at speed.

6 VOLTS/POS. GRD. NW INDIANA

The pressure is not negative.  Maybe it can be slightly below atmospheric on the inlet side but whatever the case, it was higher in the hose, in order for it to leak.

I've had coolant get on my windshield when a radiator cap was no longer functioning correctly.  There must have been a low pressure area to pull it out from under the hood and make it's way from the front to the windshield.


Lawrenceville, GA

I didn’t see this happen it but I heard it from a good friend wouldn’t stretch the truth too far. He had a 57 bird, with a/c and did a lot of long distance touring. Pulled a small low trailer for his wife’s wardrobe. Trips like Seattle-Chicago- LA on Route 66.

Hot weather, Midwest highways, he’d overheat over 70mph. He said above 70 the hood (unlatched for air flow, like in a parade) would lift till it started to block the windshield. He fitted a junk yard hood latch so the hood could move up a couple inches before the latch would catch it. With the rear of the hood open, the air flow was enough to cool the car. Given the 55-56 and 57 don’t have much difference up front, there’s a lot of pressure and strange air currents under the hood at highway speed.

Don’t try this at home, as they say. Doesn’t answer your “thunk” question.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Color me chagrined.  What felt like a ‘split’ in the hose, was actually, only a surface indentation (from rubbing against the front mount edge when engine torque-rocks).  It wasn’t leaking there after all.  I’m guessing the ‘clunk’ sound was the radiator breaking away from it’s soldered left lower mount (likely where the leak probably is).  Since the rad. is original to the car, I may try to have it repaired/rodded, though I do have an aluminum one put away, and will likely paint & install that instead.  I just need to pull the thermostat and flush out the block first.
Question: The alum. radiator’s upper hose connection has a different angle, and it looks like attaching the stiff/new OEM hose could be problematic (?).  Any advice would be appreciated.


6 VOLTS/POS. GRD. NW INDIANA

I’ve used metal tubes, usually emt electrical conduit with a piece of hose on each end. I buy a rad hose with as may bends as possible and cut pieces off to fit. Been doing it for years on dirt track engines with rad pressure caps testing 29 psi. Paint the outside satin or semi gloss black. 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Yup, I've done that very thing before as well. I use a short strap from an old life jacket strap with a short strap and a plastic buckle. Works very well. The aerodynamics of the bird hood actually keep it low enough to see without the strap. But the strap, you know, safety and all that stuff. I've been doing this with my bird since 1967 when I drove it thru the desert in New Mexico. Of course, I was only about 18 so nothing could go wrong.

       A  L  A  N   F  R  A  K  E  S   ~  Tulsa, OK    

[quote]DANIEL TINDER (8/27/2022)

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Color me DOUBLE chagrined!  Radiator not leaking (loose bracket epoxied back in place now).  When I flushed the block, reason for coolant loss was quite obvious: A timing cover bolt that also holds the gen. bracket (and plugs a coolant passage) WAS MISSING!  So, the ‘thunk’ I heard was likely either the bolt hitting the fan, or bouncing up under the car.

P.S. As a side note (related to a different/previous thread discussion re: ‘fan clutches’). I’ve decided that the replying poster was right. The added weight stress on water pump bearings (and clutch failure risk) indeed isn’t worth the minor gas savings/HP boost on a street-driven car that seldom exceeds 2000 rpm in normal use.

6 VOLTS/POS. GRD. NW INDIANA