I have been trying to trace this coolant leak, and to this point, I have been able to rule out an obvious leak from the water pump.

It is dripping off of the fuel pump, both the bottom of the pump itself, and from where the pump mates to the block. Is it possible I could have a water leak there?

Continuing my search up, There is a spot where the timing chain cover mates to the block, appears a little wet, and has a little bit of white scaling on either side of the seam. Is it possible for there to be a leak under the timing chain cover? Is it possible for the water to be getting into the timing chain cover from the water pump side?

I DEFINITELY DO NOT have water in the oil, or oil in the water. The mating for the head to the block is definitely okay, and best I can see, it is not coming from the intake manifold.

I do not have a long period of time where I can pull my truck apart and dink around, so I am needing to try to diagnose this before I take the truck offline. It started leaking about 6 months ago, and is intermittent. It is more likely to leak when hot and pressurized....but I have had it leak while cold as well.

Any ideas and suggestions would be greatly appreciated.


thank you,


ackmeister

 

dont know what engine you have but 2 of the 460s ive had were constantly leaking from the water pump/ timing chain cover area. id fix it and it would last about 6 months or so then start leaking again. these were 70s era blocks btw

 

My 429 had a leak in the front cover where there is a dead chamber between the coolant passage from the water pump and the timing chain area. There's a weep passage under the coolant passage that comes out the side of the timing cover that drains this area to keep the coolant out of the oil. The water pump had started to erode the cover causing the leak.
What engine do you have?

 

I have a 460, should be 70's era. Best I can tell, the leak is coming out where the cover mates to the block, about half way down on the drivers side (above the fuel pump).



So could my timing chain cover have rotted out underneath the pump?

 

You might try a pressure pump that goes on raditor and pressurizes the system. They work pretty well for most leaks. They can be rented at Autozone for Free with refundable deposit.

 

Correct me if I'm wrong, but I think some of the bolts that hold the water pump on go into the water jacket. If these corrode they can start to leak. When I encounter this problem I pull the bolt , clean it up or get a new one and just silicone the threads. Always works for me.

 

ckusackus, Your timing cover is most likely the culprit. I had a rotten spot in mine and it was leaking coolant into the dead space that I seen mentioned here, then coming on through the timing cover and leaking out at the fuel pump. I fixed mine with J-B Weld and its been fine for almost a year now.

Of course I had to strip the front of the motor down.

 

lol good ole JB weld. I got a new water pump a few months back, when the leak started, thinking that was it. So I reckon I will plan on a front tear down of the motor with a wrench in one had, JB weld in the other, and what the heck, swap out the waterpump out while I am at it, since I have no idea how old it is.

Superdave, did you have to remove the timing chain cover to fix this assuming it is? I would venture to guess it is rotted, as I have already had to replace a couple of rotten freeze plugs.



Am I gonna have to pull the radiator for this job or am I going to be able to get the fan and shroud out leaving the rad. in?

thanks to all for the info :-)

 

Fan and shroud should come out before the radiator, loosen shroud, loosen fan and take them out together. But the radiator should probably come out to give you room to take the dampener off. Might not be enough room for the puller and possibility of damage. Besides, those fins are sharp!
And yes the cover will have to come off to get to the passage/chamber that's rotted thru'.
Hope this helps.
Greg

 

ackusackus, Yes I had to remove the timing cover to fix mine. I had a couple of pinholes. It actually was a bit of an imperfection in the aluminum casting which had made it real thin there and it had rotted through. I ground the holes lightly with a die grinder then cleaned the daylights out if it, then went after it with the J-B Weld. Let it set for 24 hrs, put it "all" back together and it has been fine since.

This been almost a year now. Not leaked a drop still.

 

ackusackus, You also said you got a new water pump when all this started. I assume you mean you installed it also.

Did you remove the waterpump backing plate ( its sandwiched between the water pump and the timing cover ) to expose the timing cover? If the inner gasket is leaking ( the one behind the water pump backing plate ) it will also let water get into the "dead space" in the timing cover and it will find its way to the weep slot on the back of the timing cover between the block and timing cover on the right side as you would be looking at the engine.

You may want to pull the water pump back off first and remove the plate and inspect the looks of things behind it. Actually you would also be able to see if you have rotted places on the timing cover before you pull it. And remember here there are two very different gaskets on each side of that plate. (And they need to be in the right place or you will have the very leak you descride.) The one that lies between the plate and timing cover has closed in squares on the outside edges of it ( where it seals the water passages between the plate and timing cover ) , and the one right behind the pump is open except for the outer edge sealing surface.

Matter of fact if you pull the water pump plate and things look good timing cover wise, I would replace the inner gaket and outer one and put it back together to see what happens. This would be easier than pulling the timing cover. Use some good old Permatex 2 on it.

 

Actually, I have not replaced the waterpump yet. When it started to leak, I bought it, but then the leak stopped, so I decided to hold off. For the most part the leak has been intermittent, but this past week, it started leaking, and it is leaking really bad and consistently. I held on to the pump cause I figured it was just a matter of time before I did have to replace it.

Regarding the backing plate gasket, I did not get that in the waterpump kit, only the gasket that goes around the waterpump housing. Is that something I have to get seperately, or will I have to make my own?

 

Should be in the front cover gasket set.

 

ackusackus, You have to get the inside gasket seperate. Just specify you want the gasket that goes between the backing plate or and the timing cover, and if it looks like the outer water pump gasket they gave you the wrong one.

 

very cool, thank you very much!!!!!!!!