Hi Everyone,
I have a 1995 F-150 4.9L manual trans with 137K miles. For the last couple of months I've had a coolant leak dripping from between the engine and the transmission. I just assumed that it was blowing back from the front of the truck when I drove it and then it would drip from there. Well, I've replaced the thermostat housing, thermostat, bypassed the heater core, replaced the radiator, all the hoses, and the water pump-all with no leaks. I just got back from the test drive after the new water pump and radiator and guess what...it's still dripping quite a bit from my transmission. I've had two mechanic's look at it and they can't find anything and so I thought I'd put it out there for you guys to discuss. Any help would be appreciated. I use this truck for hauling my Dune buggy out to the sand dunes and that season will be here shortly so I need the truck to be reliable.
thanks,
Nick

 

Freeze plug? I dont know where theyre located on the engines but maybe. Does your oil look ok? What about a head gasket leak?

 

The oil is fine and no steam from the tail pipe. The truck runs beautifully. I never thought of a freeze plug. I live in San Diego, CA where it doesn't get below freezing, ever. I'll check it though, thanks.

 

they rust out.

pressure test the cooling system at a radiator shop.

 

Coolant can be leaking from a heater hoses or intake manifold and traveling down to the back of the motor/trans which is the lowest point...........take a look in those areas....But as always, the pressure test will tell all.

 

Conall:
Had similar problem on 94 Ranger. Passenger rear corner of intake manifold had rotted away next to coolant channel. Had to pull intake build it up and reshape. Probably would have been cheaper to get a used intake from part yard.
Good luck.

 

Sound like a head gasket or freeze out plug. Clean the engine, then pressureize it. Keep an eye on the head gasket in the back. If that is not leaking it must be a freeze out plug`

 

I have a '93 4.9 with 5-speed that had the same problem. It was the freeze plug on the rear of the engine. It can be replaced without pulling the transmission. The others are probably rusty too, especially if has been run with straight water or low coolant to water mixture.

 

I know, it is most likely a freeze plug or a head gasket, but on issue i had on mine that took me a while to figure out.

I had a pin hole leak in a heater hose. you could hardly see it even if you were looking. And it only leaked when i was driving for some reason. And when ever i would park and pop the hood every thing would be covered in coolant. It was extremely aggravating.

Again, i know you have looked over it carefully, but you never know.

Good Luck!!!

 

again, that is why you use a pressure check to test the cooling system.

 

Well, It turned out to be all the freeze plugs. I had to replace six steel ones with new copper ones and it was a real pain. I had to remove the transmission to get two and the intake and exhaust manifolds to get the rest. But, I did a bunch of work that needed to be done at the same time and the truck runs great. Thanks for the help.

 

so even in california things rust out.

who would have thought such a thing could happen.

glad you got it fixed and thanks for the update.

 

oh yeah, we have a little rust out here but it's not too bad unless you live right on the ocean. The salt air really works over a vehicle. These freeze plugs are the only rust I have on any of my vehicles...
I got this truck from my brother and it's possible he didn't take proper care of the coolant as the freeze plugs were rusted from the inside out.

 

I had the blocked off coolant transfer ports peeing out a bad intake gasket at the rear. and you havethe freeze plug idea....and of course a good ole head gasket seep to the outside.

worst case scenario would be the tranny cooler failing and you shifting on prestone....yuck.

 

Freeze plugs.

I see the requirements for freeze plugs in cold weather areas but why not use a different metal type for the plugs Mr. Ford Engineer?

To late now....also happens with other manufacturers. I had an olds with a 350 and all the freeze plugs had to be replaced and it was a Texas car.

Coolant Maintenance issue by PO or poor design of the plugs? Who knows.

I needed the car and until I got bucks for a fix I drove it a mile, let it cool for 30 minutes then put in water then drove another mile.

Ahhhh the good old days.....