I'm getting a rad fluid leak from the torque converter cover hole after driving the car for a few minutes. Checked the back of the intake and nothing there. Trying to figure out if there are any freeze plugs on the back of my 1969 455 block where the tranny mates up. I checked the csm and it only points out a cup plug and camshaft plug. My 350 on a stand only has those plugs as well...are there any other plugs on the back of the block I'm not seeing that a 455 has and a 350 doesn't. Just trying to get everything straight before pulling the tranny off. thanks

 

Make sure you check that rear heater hose connection at the back of the intake. I've had them leak but only when hot & under pressure. Are you using the vac operated heater control valve(a/c car)??? They can leak through the little vent holes for the diaphragm if it ruptures.

 

Thanks Rob but I'm not using the heater core right now so there are no hoses to the intake as the water pump has a cap off right now...just trying to figure out if there are freeze plugs at the back of the block as the CSM is vague and I can't see it on my spare 350.

 

The only way for coolant to get into the bellhousing is from a leak at rear of the intake or the head. My first guess would have been a leaking heater control valve, but if you have your heater ports capped, look for leaks at the caps, or the back of the intake gasket, or the back of the head gasket. The other, much less likely possibility, is a crack at the rear of the block that goes into the water jacket. There is no other way for coolant to get there. The plugs on the rear of the block in the bellhousing area don't go into the cooling jacket.

 

I've had condensation on the torque converter before that made a puddle on the floor.Is the humidity high there?
railguy

 

Unless you're near Three Mile Island, condensation wouldn't be Prestone Green.

 

Thanks Joe I'll take another look again. I've also noticed that my thermostat housing is leaking. Is there a possibility that under high RPM the housing leaks more and then sends it down the intake and out the back to the torque converter cover drain hole. I've checked the top of the intake and there is some staining but given the amount that drips from the cover I would think that residual liquid would stay on the top of the intake...but nothing shows up other than staining. Just wonder if this is a possibility. thanks

 

Certain coolant leaks seem to happen after the car is turned off hot, and the temperature and pressure go up. I've had a couple minor leaks over the years that did this. Never when it was running and I was looking, but I'd come back later and there was the puddle.

When I first read the thread title, it reminded me of something a buddy told me about. He works for Benz, and they had an issue at one time with transmission fluid getting into the radios. It was somehow working its way in via one of the wiring harnesses ha ha. True story, he saw it. I don't think your problem is of this variety...

 

Ok here's the update. After taking the car for a drive I brought it home and with a glove ran my hand again through the whole aluminum intake back location. Low and behold there was the leak in the very bottom corner of the intake where it meets the heads on the drivers side. It's not gushing out but it's definitely leaking at a moderate clip. Torqued the intake screws again as the motor is a recent rebuild and got a bit better but not much. So here's my next question and I'm sure you know where I'm going

Is there a less painful way of plugging that leak other than doing a re and re on the Edelbrock air gap aluminum intake? Is there some RTV type of sealant I can try jamming into that exact location to plug up the leak that works well? Thanks for any ideas but if majority say re and re than pain it is.

 

You can try to loosen the bolts on the RIGHT side first then the LEFT and re-tighten the left first then the right, Might be able to shift the intake enough to stop the leak, That is if the gasket is in place. Good luck

 

I would suggest you just R&R the Gasket. If its leaking on the outside, it could possibly be weeping on the inside as well.

 

This isn't the sort of thing you want to take shortcuts with, especially with a newly rebuilt motor. You want years of trouble-free. Do it right and then you don't have to worry about it.

 

^^^This. There is no way to apply sealer from the outside that will do any good. Get a new gasket, and read and follow the installation instructions in the Chassis Service Manual. Pay particular attention to applying RTV around the water ports on the gasket and inserting the four gasket locating features into the locating holes in the heads.

 

My thermostat housing gasket was leaking and the coolent would pool on top of the air gap manifold. When I would accelerate it would slosh to the back of the engine when I hit the brakes it sloshed to the front but the funny thing is it didn't look like it was leaking.

Replaced the gasket with a thin layer of honda bond (I'm a honda tech) on both sides and it's fine now.

 

The leak has gotten much better over time since the torque down but I'm going to do the r and r regardless since it broke through already. I've looked at the CSM and it's my first attempt at this so I'm going to do a trial on a spare 350. Is there a special technique to putting RTV on the front and back of the block where the intake sits? How much RTV do I put around the water jackets of the gaskets based on experiences of others? Sorry it's my first attempt and don't want to bugger this up. Thanks.

 

The RTV bead should be about 1/8" wide, though this is not that critical. Be sure to apply RTV around both sides of the gasket (top and bottom). Note the four embossed locating bosses near the corners of the gasket and be sure they fit into the locating holes in the heads. Some aftermarket gaskets have had those bosses improperly stamped, so try fit the intake to the heads before applying RTV. Also, I have never had good luck getting the rubber end seals to stay in place, so I just throw them away and apply a heavy bead of black RTV on the front and back edges of the block before installing the intake. I usually let the RTV skin over before installing the intake. This isn't difficult, just pay attention to the details and be aware that the iron intake isn't light. Watch your back.

 

Thanks everyone for all your assistance. One last question...when placing the Edelbrock AirGap aluminum intake back onto the factory J heads should I torque the ARP 3/8" bolts the builder used to factory 35 ft/lb? Thanks.