Hi sparky, just a suggestion, try sliding a piece of white thin cardboard or similar under thermostat housing/hose area, run engine, leave to cool off then watch for water drops after turning it off, it may just leave indication of leak origin. Good luck. Aussie Bill.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

Check the front ear of the intake on that side for cracks.  Sometimes the front valley pan bolt isn't tightened enough and the intake hits the head of that bolt.  Then if the front bolt of the intake is tightened first (I know, that's the wrong sequence, but Murphy may have worked on it before you got it) it can crack the ear.  Come to think of it, if the valley bolt is hitting the manifold, maybe the manifold can't tighten against the gasket.

John in Selma, IN

John - "The Hoosier Hurricane"

Considering where the water passages are in the heads it is unlikely to leak up into the valley cover area pretty much ruling out a head gasket problem.  This leaves only a leak at the intake manifold to head junction if everything is otherwise OK as you say. Can you see coolant running along the top of the block between the valley cover and head when you look down between the runners of the intake manifold?  You could dry everything off again then run a pressure test with a radiator pressure tester and watch closely to see where it starts.  The long bolt at the front of the right side of the Intake manifold is very close to the water passage  and the gasket is pretty thin. BTW some old aluminum manifolds get porous where they get close to the head in this area which is probably some kind of electrolisis so there could be a pin hole (if you have an old Al manifold).

Doug T

The Highlands, Louisville, Ky.

I sealed the studs today, and new intake gaskets. Still have water running between head and valley pan on right side. I'm convinced water not coming from either one of these or t stat housing or bypass hose, whats left?

You can remove the studs by double nutting the top portion of the threads and then unscrewing the studs with a wrench in lieu of not having a specific stud removal tool.  Almost any kind of sealer will suffice on the threads but my sealer of choice for this is either a thin film of RTV or some K&W CopperCoat on the threads.  Removing the studs that are not leaking and putting some sealer on those while you have the intake off would be highly recommended.  Might save you some grief later.

I also use K&W CopperCoat on the intake gaskets but if I know I’m doing a series of intake manifold changes (dyno testing) then I’ll simply coat the gaskets with white grease on the intake manifold side so I can reuse them.

Lorena, Texas (South of Waco)

Ted, I think you're on to something, I removed the intake yesterday and looks like a water trail coming from the two studs on right side. I got one stud out but the other one won't budge, any ideas how to get it out and what to put on them when I do. Should I mess with the left side or leave them alone since they don't appear to be leaking. Also,do I need some kind of sealant on the new intake gaskets? Thanks for all the replys.

I have had gaskets "Weep" a little on a fresh engine before and all you have to do is run the engine a while, let it warm up, and most leaks take care of themselves. Also I have been sent bullitens from some gasket co. that it is best to break-in an engine with Water before adding coolant, this helps the gaskets swell.

Tim

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

The earlier model Y heads did not have the ‘blind’ threaded holes in the heads for the four studs holding the intake manifold down which means coolant can leak from these particular threaded holes.  If sealer was not put on the threads before installing the studs, then some coolant weepage can occur at this spot and it will run down alongside the valley cover and leak at the back of the engine.  This particular leak is typically hard to find because it’s such a small leak to begin with and typically shows up as a very small puddle under the vehicle at the back of the engine usually after the engine has been shut off.  Sometimes looks more like a leaking head gasket than what it really is.

Lorena, Texas (South of Waco)

It happened to me too!  The leak was seeping from between the thermostat housing and bypass tube, and took a good, frustrating two hours to figure out.

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

 

Same thing for me, it was a slight trickle from the upper hose (I could barely see it) it hit the valley pan, ran down to the back end of the engine, and was dripping off of the bellhousing.  

A.J.

South Jersey

SMSgt USAF Retired 
1955 Ford Ranch Wagon & a couple of old guitars...Life's Good!