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block crack, UGH


TFC

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Been working on getting my 52 B3B back on the road,  ran into a coolant leak I was not expecting.  Pic attached.  Not sure what my best option is here, not really up for pulling the engine out again.  Any advice is greatly appreciated. 

crack.jpg

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TFC, that topic has been discussed here for example -> http://p15-d24.com/topic/45136-cracked-block-now-what/

Certainly one of the best solutions that you have. But of course nothing someone can do on a Sunday afternoon ...

 

Welding would also be possible, but would require to pull and dismantle the engine. Also the right equipment and welding skill is required (cast iron).

 

There are also endless examples in the www. Try a search for videos.

 

I totally understand your wish not to pull the engine. So, since your crack seems not to be huge, I personally first would try it less troublesome:

1. Drain the coolant

2. Drill a bore to each end of the crack (to avoid it tears further). But I wouldn`t drill it completely through. Eventually you could get an issue with 6.

3. Carefully / slightly open the crack with a grinder (not too much ! Maybe 1/3 in depth)

4. Thoroughly clean the crack with a solvent cleaner. Dry the area with a hair dryer. Repeat if necessary.

5. Take a 2 component epoxy resin. Mix iron powder to the epoxy. Not too much, it still should be fluent.

6. Fill the crack with the epoxy. Maybe a injection will help. To make the epoxy temporarily thinner, eventually heat the area with a hair dryer.

7. Stick on a good adhesive tape

 

Sounds more complicated than it is. My Dad did this at a crankcase of an light-aircraft (!) He had run it for several years with no issue.

Good luck ! Jan

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FEF has a VERY similar crack.  I've cleaned it up 2 times now and applied POR exhaust manifold filler and it lasts about 3 years.  I hope this winter to get it fixed permanent (lots of parts to pull off to do so  :(  I feel your pain.  As long as it's just the water jacket it's not the end of the world.

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Thanks guys,  Was thinking about running a sealant in the coolant.  Also thought about drilling the ends, grinding a trough and filling it with the ever popular "JB Weld".  Jan, curious why you would not drill all the way through?

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My buddy built performance motors for over 40 years and he said NEVER use Bars leak. Although my dad worked for FWD Segrave for 43 years and he said every truck left the shop with two cans of Bars leak in it. 

Inquiring minds want to know???

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I worked for a good sized crane, forklift, boom,sissorlift rental company.

 

WE purchased every piece of equipment used from many sources and any and all repairs were done in our shop before ever rented out.

 

We also had about 30-40 forklifts with Mopar flathead engines, mostly 25" type. Every new (used) purchase of these had the radiator and block flushed out and radiators were sent out for repair if needed.

All were put back together with antifreeze, a can or two of Bars leaks (i do not remember if it just was one 1 can or more), at least one, plus about half of a #303 can of water pump lubricant. I am not sure that stuff  (water pump lube) really did any good. The owner and boss said to add it -- Sooooo.

 

They often were out on rent for 6 months to 1 year plus! Never had any leaks. 1 blown head gasket in 110 degree weather in 5 years was pretty good I would say!

 

DJ

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I have done some serious block cracks and use "Stitch and Lock" threaded pins.... expensive but will be done right.... never ever a leak and can be hidden 100%

JC 413 Max Wedge Pinning Block (19).JPG

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Belzona is expensive and a very good product .

I used it on an Airflow cracked block.... Vee'd the 2" crack 1" below the deck. Cleaned out well and used this product as a trial....leaked slowly a month later.?

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I'd try one of the glue/filler/epoxies first.  Low cost, fairly easy to do, and no real downside to trying it.

 

If possible the crack should be ground wider at the bottom than the top and not all the way through.  that leaves a floor in the damaged area that prevents the filler from escaping when pushed firmly in to adhere.  A Dremel type tool works well the the last stage of that.  Slow but easy to control.  The undercut doesn't have to be big, just enough to key the repair to the block and provide more surface area of adhesion.

Probably use JB weld as it has worked well for me in the past.  push it in well. If needed you can texture the surface with a piece of coarse sandpaper on it until it after it sets up some.

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Thank for all the input.  Spent sometime on this problem yesterday.  Drained coolant, got in there with my dremel and sandpaper, my intent was to clean area up see extent of the crack, drill ends to stop its growth.  After cleaning the area found it very hard to see the crack even with a magnifying glass.  Had to refill with coolant to get it to weep again just to see where it is.  My thinking now is to punt,  just run a block sealer in the coolant and see what happens.   Good Idea? 

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You went through all the work to grind it and prep it just clean the coolant off very well and JB weld it. My dad always said there is two ways to do things. The right way and the wrong way.  

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I wouldn't stop drill that, no matter your final fix choice.  stop drilling is intended to stop crack growth due to vibration or movement resulting in metal fatigue.  Neither of those are present in that location as it is presumably a freeze crack.  One time pressure fracture not a 'shake and break' situation like a fender or frame.

 

Your almost there with the cleaning and dremel work.  I'd use some of the the little fiber reinforced disks to cut a narrow channel, maybe 1/8" down or a little less.  Then angle the disk both ways to widen the bottom.   a little epoxy and you're done.

 

The additives will certainly stop it, but I worry about heater cores.  And, it may open up again at the most inconvenient time, especially if you drain and flush as a maintenance item.

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51 minutes ago, kencombs said:

I wouldn't stop drill that, no matter your final fix choice.  stop drilling is intended to stop crack growth due to vibration or movement resulting in metal fatigue.  Neither of those are present in that location as it is presumably a freeze crack.  One time pressure fracture not a 'shake and break' situation like a fender or frame.

 

Your almost there with the cleaning and dremel work.  I'd use some of the the little fiber reinforced disks to cut a narrow channel, maybe 1/8" down or a little less.  Then angle the disk both ways to widen the bottom.   a little epoxy and you're done.

 

The additives will certainly stop it, but I worry about heater cores.  And, it may open up again at the most inconvenient time, especially if you drain and flush as a maintenance item.

Ken,  Thanks of the input, particularly about the stop drilling.   My preference would be not to drill especially since it seems impossible to find the ends. 

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If it were my truck I think I would try a sealer mixed in the coolant first. Run it for a while and monitor it closely. A crack like this is likely to stop up with the sealer. The sealer will not work if the leak is stopped by external epoxy. The block sealer needs to flow into the crack when the engine is up to temperature in order to form a bond.

Once this has taken place then you can do a external cosmetic repair.

Jeff

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Pretty sure Bars just works on small leaks in radiators. There is "better" stuff that is supposed to work well in fine cracks in steel and cast iron. It is a liquid that has some sort of ultrafine ceramic particles in it along with a heat activated bonding agent. Be damned if I can remember the name of it. Next time I see one of my mechanic buddies I will ask him. I know that he has had some positive results using it.

Jeff

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That upper crack area is fairly common on Mopar flatheads....

It can be caused by pulling up too hard on the block deck area... this.by over tightening a 7/16" X 20 fine thread stud.... 55lbs is the max torque on a head stud nut ...

Never torque to 60-70 Ft lbs on a stud/fine thread nut fastener being used on a cylinder head...

.60-70Ft Lbs torque only the 7/16 X 14 course head bolts?

 

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3 hours ago, Dodgeb4ya said:

That upper crack area is fairly common on Mopar flatheads....

It can be caused by pulling up too hard on the block deck area... this.by over tightening a 7/16" X 20 fine thread stud.... 55lbs is the max torque on a head stud nut ...

Never torque to 60-70 Ft lbs on a stud/fine thread nut fastener being used on a cylinder head...

.60-70Ft Lbs torque only the 7/16 X 14 course head bolts?

 

Thanks for the observation, Sure hope I did not cause this, did switch from bolts to studs/nuts with this rebuilt.   Yes, I did dial the torque back(55ft lbs) as required with the fine pitch thread.

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Guess we all have our experiences.  My experience with Barr's leaks has been nothing but positive.  Most dramatic was with a coolant leak between the piston jug and block of a Subaru horizontal/boxer engine. Leak went from 1 drop per second to zero within about 15 minutes.  With your truck, may have to pressurize the cooling system with a 15 psi radiator cap unless your using one already.  My B1B cooling system is not pressurized.  If I had your leak would definitely try Barr's Leaks with 15 psi radiator cap.

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10 hours ago, squirebill said:

Guess we all have our experiences.  My experience with Barr's leaks has been nothing but positive.  Most dramatic was with a coolant leak between the piston jug and block of a Subaru horizontal/boxer engine. Leak went from 1 drop per second to zero within about 15 minutes.  With your truck, may have to pressurize the cooling system with a 15 psi radiator cap unless your using one already.  My B1B cooling system is not pressurized.  If I had your leak would definitely try Barr's Leaks with 15 psi radiator cap.

 

I believe on a stock radiator the weep line is below the rad cap and a pressure cap does nothing.

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Mark;

Think about this for a moment. The system needs to be pressurized for any of these products to work well. They need to flow into the crack in order to seal it. Doesn't need to 15#....4# would make it work. But in a 0 psi system there isn't much chance it is going to be forced through the crack.

Jeff

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