Water Leaks Through the Block

[TK in LA]

What is the opinion (like belly buttons) of a leak from the water jacket. I've seen a couple of blocks in the past the the water jackets have rusted through causing water to seep. One I saw was brazed and didn't leak. Is the block salvageable of scrap?

 

[Ray in La Mesa]

Outside leaks in the water jacket can be repaired with JB Weld very successfully. I clean and enlarge the hole back to good metal inside and out. Then I smear the JB Weld on the inside edge of the hole before I cover the outside to give it more bite. You can use masking tape to keep the JB from sagging till it drys.

 

[pat in Santa Cruz]

depends on where the leak is from. Common areas are below the water pump where it gets thin, and along the lower curved area of the water jacket where it cracks. The cracks can be ground and filled with JB Weld. Its not the best thing, but the engine will go on for a long time that way if you're just trying to keep it running. I had one block that was rusted so thin below the water pump that I scrapped it because it was time for a rebuild anyway and its not worth the time and money to risk a re-build on a bad block.

 

[billwill]

What is the opinion (like belly buttons) of a leak from the water jacket. I've seen a couple of blocks in the past the the water jackets have rusted through causing water to seep. One I saw was brazed and didn't leak. Is the block salvageable of scrap?[/I would try to salvagethe block.than it depends where it is leaking.

 

[Special Coupe Frank]

Depends on whether you're talking about an external leak or internal....

Since the stock Model A cooling system is not pressurized, you stand a better chance of successfully repairing external cracks with JB Weld, PC-7, or other epoxy systems than would be possible with a modern engine.

It might be worthwhile to examine the rest of the engine and assess it's total condition... if it's already been bored a couple of times and/or has internal cracks, it might be better to find another block ?

Model A engines are also known to develop cracks across the deck surface of the block, either between the valve seats or from the valve seat to the cylinder bore...

Again, these can sometimes be repaired, but if the rest of the block has been bored extensively or has other damage, it might be more feasible to find a better block ?

Better to get a total picture of what you're up against before you start investing time and money on surface repairs, in my opinion.

Good luck with it !

SC Frank

 

[TK in LA]

Thanks for all your comments. The one I'm currently concerned with is a water leak through the casting to the outside under the water pump. I've seen the repairs to the block internally where the crack was pined and welded with good success and I've also seen where the outside leak was brazed but you'd need to turn the block over to do it properly. I've tried JB weld on an external leak in the past but with not a lot of success. The motor needs to be rebuilt probably but doesn't smoke or overheat. I'm in the process of trying to sell the motor when I noticed the leak. I don't want someone to buy it if it isn't worth saving.

 

[Special Coupe Frank]

If you can, you might want to drill a small hole (1/8") at each end of the crack, to prevent it from growing longer; then grind it out a bit to give the JB Weld something to hold onto...

Whether you repair it or sell it as-is, make the buyer aware - if they decide to buy the engine, they were informed...