Coolant leaking from block

visionary

visionary

Senior Member
Since purchasing my 29 ccpu 3 years ago i noticed that it would leak a very small amount of coolant down the front of the motor and then onto the garage floor i always just figured that it was coming from the water pump, but it's not. it's actually leaking out of the front of the block casting about 3" below the head gasket just underneath the radious.

I cant see a crack but that doesn't meen there isn't one. it doesn't apear to be leaking into the oil or combustion chamber, just external. so i'm wondering if it could be a porous casting? any thoughts?

I'm tempted to try some kind of stop leak product in the coolant but i'd hate to plug the radiator, it runs nice and cool.

Thanks
Scott
 
I had a leak from the block of one of mine. It was from the back of the block in a newly restored motor . Both the engine restorer and myself missed the small hole in the block and we discovered it when we filled the car with water prior to inital start up .:( The fix was easy we just drillled the hole and threaded a brass plug into it . Unfortunately in my case we had to pull the engine out to do this. Been fine ever since . I and the engine restorer now pressure test all our blocks prior to restoration. Karl
 
Very well could be; however, try this:

1. Clean any oil/grease residue from the water pump/head gasket down.
2. Thoroughly dry this area with paper towels.
3. At night with lights out, get a flashlight to shine on this general area.
4. The reflection of the light off of the leaking water will pin point the source of the leak. (Many times sources of small leaks cannot be pinpointed in daylight or with an overhead garage light).
5. If the water pump gasket is leaking, it can be repaired; however, if the leak is coming from the side of the block, get some typewriter "White Out" paint & mark the exact location of the source of the leak.
6. Grind off engine paint & investigate -- someone may have previously plugged this leak.
7. If a cast iron leak, sounds like J.B. Weld may be the solution.
8. Report what you find.
 
Thanks for the info, the block is extremely clean, it doesn't apear to have a lot of paint buildup. you can actually see the dropplet form in the area just under that radious in the very front.

i like the idea of using a mirror for closer inspection, and i never thought about using JB weld.

Thanks
Scott
 
Hi Scott,

I'd still verify area with a flashlight at night to make sure & pinpoint "exact" leak source -- a thin film of water is always most difficult to see -- the water in the curved area would be readily seen if this is the first water accumulation drip point.
 
i would jb weld it also you got nothing to lose and can always go the pinning route if need be
try not to put any fix it in a can in the cooling system
 
On my B engine,I had a leak at the same spot at bottom of water jacket that showed up after cleaning cooling system with vinigar.I ground it down to bare metal & applied some JB weld & it,s been fine since.
 
Mitch//pa said:
i would jb weld it also you got nothing to lose and can always go the pinning route if need be
try not to put any fix it in a can in the cooling system
Click to expand...

We had a member that ran his engine for years and when it was rebuilt it was found to have a bullet hole in the jacket in the front of the engine that was saeled with jbweld.
 
You mean a crack like in this picture?
These are common on Model A due to freezing and stress. They can be readily repaired by metal stitching we use or a stop gap repair would be block sealer or JB weld as a last resort.
http://www.jandm-machine.com/metalStitching.html
 

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Originally Posted by Ed,
There are two different types of JB weld. There is a quick set, and there is the standard type that requires at least 24 hours to cure completely. The standard type is what you will want to use. I have not had any success using the quick set JB weld.[/QUOTE]

Scott,
You are from an area that has freezing temps...I would guess you have a frost crack and the area you describe is where I see many of them. Your options after confirming the crack are metal stitching, JB Weld or maybe a block sealer...I have not trusted just a block sealer for this type of block damage but I'd like to hear if any others have had success. Metal stitching is best left to a professional as the casting is very thin in the area you describe. I have the stitching pins and experience in their use to make this repair but find the JB Weld method works well also. JB Weld repairs must be executed carefully for them to give a long service life.
IMO, Ed has it right in his statement quoted above...use slow set JB Weld. I also have had good success with the slow set JB Weld for these types of repairs. I suggest: Locate the crack exactly...I have a Magnafluxing tool and am able to locate the crack in most areas of a block. Those that I can not, I use a block off plate that allows me to pressure check a block and soap the suspect areas. After marking the crack area, shallow "V" cut the line of the crack about 1/32" deep and then carefully clean/roughen the surfaces around the crack. I use a Dremel tool with narrow cutting wheel to groove the crack. I often make two additional shallow cuts about 1/8" away from the crack meeting these two cuts beyond the ends of the crack to provide an additional key to the repair. I use a course emery cloth to remove all paint and roughen the surfaces. I typically remove all paint and roughen the surface at least 1/2" beyond the repair area. Use a stiff putty knife to force the JB Weld into the grooves and finish with a thin coat over the entire cleaned area feathering to the edges. If you are careful to blend to the adjoining surfaces, the repair will not be visible. After a couple hours of setting, a course piece of sandpaper can be pressed into the repair to give it a texture to match the adjoining surfaces. I have been doing these repairs for about 10 years and have not had one leak yet. One other comment: I live in Minnesota and we need to be careful with our engines during the long freeze. I suggest using anti-freeze in an engine that has this type of repair if the engine will be subjected to freezing temps. If one is not using anti-freeze, I do not know that draining the engine of water as the only prep for winter will be enough to protect the repaired area. I think many of us don’t drain the engine until the last moment and not leaving enough time to dry the crack area from within, may cause the repair to “lift”.
Good luck with your repair.
Dave in MN
www.durableperformance.net
 
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Hi Dave,

"Some" dentists are aware that slow set epoxy has far better adhesive properties to adjacent un-alike materials than fast set epoxy for glueing crowns on teeth.

Allso, as you cautioned above, patience to provide clean, properly prepared surfaces are of utmost important to avoid JBWeld failures.
 
I have, to pinpoint the exact spot, especially if it is a very slow weep, used the blue shop type of paper towels, one layer and tape it over the area. it turns dark in the presence of liquid very quickly and will help pinpoint the spot if it is *very* slow to drip..

Hope it helps,

- Dave
 
After taking a closer look with a mirror it looks like a small crack less than an inch long, it's in the same spot as the picture posted by J&M machine.
it has actually formed rust in the crack highlighting it enough that i should be able to v it out with a dremmel tool and use the original formula JB as sugjested.

It really only leaks when the motor is warm, the heat must open it up enough to leak and when it cools down not much of anything comes out.
since i've owned the truck it's always been stored inside my heated shop with antifreeze in the system, so i'm guessing it's probably been like this for a long time.

I allways look foreward to coming on here most everyday and appreciate all your help.

Thanks Again
Scott
 
When using J.B. weld on a vertical surface it has a tendancy to run until it is starting to set up a bit. This can take a while so when doing something like this I like to mix up a small amount as a test batch. Then about 15 to 20 minutes later mix up what I am going to use for the repair. Keep an eye on the first batch and when it starts to set up just enough not to run you then know how long you have to apply the second batch. Works for me.
Dave
 
I have dealt with the tendency of JB to run by taping it in place with the wide green painters masking tape. The tape should overlap the JB weld well for good adherence to the iron as it does not stick well to wet JB. Works like a charm and peels off well after its set. Any that sticks can be sanded off.
 
earbleeder said:
what about welding? what is the block made from exactly?
Click to expand...

Cast iron, thought to be somewhat weldable with arc welded nickel rods but this is not recommended to most people because of potential warping or cracks forming right next to the weld. It can be done but usually only done after the engine has become very worn & damaged so that subsequent operations do not seem like such a chore.
 
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