1967 Ford F250- cooling system flush w/ Cascade??

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I have flushed the system out best I can with plain water several times until it all flows clear, but it doesn't take all that long for the coolant to start looking a little dirty. I was reading several places that Cascade makes a good flush chemical, but would it be OK in an engine like the 352 in my truck? I'm thinking there must be gunk trapped down in the block somewhere that isn't releasing with a normal flush. I have a new water pump, 4 core radiator, thermostat, hoses, and everything like that. Still gets hot if I let it idle too long. We have Cascade dishswasher gel under the sink, not the powder it seems like a lot of folks prefer. Open to suggestions.

Thanks
 
If the lower freeze plugs along each side of the block have never been removed, there's probably a TON of debris down there. When I pull those out of older engine blocks, I find casting core wire, sand residue, thick iron oxide "silt" and all sorts of stuff. Back when my '66 had its original 383, there was a time when it would turn new coolant into coffee with cream in a couple of weeks. A freeze plug started leaking, so I bit the bullet and popped all six out to replace them with brass plugs, and found all that mess. I used a straightened coat hanger to dig out both sides of the block while flushing with water into the thermostat housing from above (thermostat removed). After that, the engine ran another 15 years before I retired it and the coolant never got even slightly cloudy again.
 
Google says. Mechanics Forum.

Getting rid of those deposits is tedious but not difficult:

Drain the coolant and flush with tap water (dispose of the coolant safely!)
Fill the cooling system with about two cups of liquid dishwasher detergent dissolved in hot water.
Start the engine and run it until it warms up to regular operating temperature.
Drain the detergent solution and flush with tap water again until it runs clean. (The idea here is to remove all oils from the system.)
Fill the cooling system with two pounds of citric acid powder (available from industrial chemical supply houses, or from Mercedes-Benz dealers at a considerable premium) dissolved in hot distilled water (since your tap water is hard).
Again, start the engine and run it until it warms up to regular operating temperature, or at least fifteen minutes.
Flush with distilled water. At this point you should see all sorts of rust, mineral deposits, and miscellaneous crud loosened by the citric acid come out of the drain hole.
Refill the system with the appropriate mix of coolant and distilled water. Use a modern "long-life" orange coolant if you have an aluminum cylinder head, block, or both--green coolant promotes corrosion in aluminum.

Instead of Citric acid you could try vinegar.
It could take a lot of distilled water to flush all the [censored] out, several flushes.
 
Does this truck have a fan shroud on it? Being as old as it is they sometimes get pulled off and never put back on.
 
Mercedes Cooling System Citrus Flush

When I change the coolant again in my Volvo or Olds, I am going to use the above method. I have a super easy to access block drain on my Volvo, so it gets a lot of the gunk out of it.

If it has a clutch fan, give it a good spin, and if it spins like a top it's time to replace it.
 
I read CLR was good for flushing cooling systems. You might want to check that out.
 
CLR says "not for aluminum" right on the bottle. I might be tempted to try it BRIEFLY.

I've used Cascade dishwasher liquid with success.

There's a product called "The Works" and even though it's been weakened recently, I'd consider trying it briefly too.

Heck, why not try the Mercedes product?
 
The truck didn't come with a shroud as far as I can tell but I recently picked one up from a different year. Hope it fits. I don't think there is any aluminum in the system, but not sure. The fan is a solid fan, no clutch. I even upgraded from the stock 4 blade to a 6 blade rigid fan. Not a flex fan.
I do some work at a Mercedes dealer on occasion so maybe I'll talk to the techs about the acid powder. Sounds like starting a good cleaning with the cascade would be a good start no matter what. Shouldn't cause any damage from what I can tell.
 
Rig a flushing tee in the htr hose and reverse flush. What color is it? Rusty red or old shoe brown? If it is OSB, then it may be sealer. Last time I flushed a radiator cause it was dirty, the radiator sprang a couple dozen pin holes. Carefully remove the thermostat for best results. Carry water with you until you fix this. Good luck with this beast. Fix Or Repair Daily
grin2.gif
 
Originally Posted By: Koz1
Google says. Mechanics Forum.

Getting rid of those deposits is tedious but not difficult:

Drain the coolant and flush with tap water (dispose of the coolant safely!)
Fill the cooling system with about two cups of liquid dishwasher detergent dissolved in hot water.
Start the engine and run it until it warms up to regular operating temperature.
Drain the detergent solution and flush with tap water again until it runs clean. (The idea here is to remove all oils from the system.)
Fill the cooling system with two pounds of citric acid powder (available from industrial chemical supply houses, or from Mercedes-Benz dealers at a considerable premium) dissolved in hot distilled water (since your tap water is hard).
Again, start the engine and run it until it warms up to regular operating temperature, or at least fifteen minutes.
Flush with distilled water. At this point you should see all sorts of rust, mineral deposits, and miscellaneous crud loosened by the citric acid come out of the drain hole.
Refill the system with the appropriate mix of coolant and distilled water. Use a modern "long-life" orange coolant if you have an aluminum cylinder head, block, or both--green coolant promotes corrosion in aluminum.

Instead of Citric acid you could try vinegar.
It could take a lot of distilled water to flush all the [censored] out, several flushes.

I would first do the citric acid flush THEN the detergent flush. The system should get some kind of neutralizing treatment after the acid flush, and the detergent flush would do that.
 
The fan shroud will be a big help for cooling at low speeds.

I have used the detergent trick before, worked well.
 
Originally Posted By: DuckRyder
In stock configuration without air - the fan should makes little difference in these trucks...


I guess not everyone has the same experience. The shroud made a big difference in my '78 F250.
 
Originally Posted By: Rob_Roy
Originally Posted By: DuckRyder
In stock configuration without air - the fan shroud makes little difference in these trucks...


I guess not everyone has the same experience. The shroud made a big difference in my '78 F250.


Guess so, 67-72 is a bump side, 78 would be a dent side which I don't know much about.

I put a shroud on mine in preparation for A/C and it made no difference, of course it did not even come close to overheating without the shroud and a 3 row radiator...
 
It had a flushing fitting in heater hose before, but I replaced all the hoses this time and didn't put it back. It looks nice and bright green for a little while but starts turning brown. I bet the block is dirty with muck. It's stick shift no AC and runs good. Just gets hot after extended idle. Not nearly as bad as before new radiator and water pump and all.
I pulled a shroud from a 66 but don't know if it will fit my 67.
 
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I let it run about 15 minutes with the dishwasher liquid in the system. I plan on doing it again tomorrow before draining it. Make sure it had a chance to clean out as much stuff as it can.
 
Originally Posted By: Kira
CLR says "not for aluminum" right on the bottle. I might be tempted to try it BRIEFLY.

I've used Cascade dishwasher liquid with success.

There's a product called "The Works" and even though it's been weakened recently, I'd consider trying it briefly too.

Heck, why not try the Mercedes product?


You're right, but in the case of the OP I don't think he has much if any aluminum to worry about in his 67 Ford. The people who have used it run it for a short period of time and reported good results in cast iron and aluminum engines. Then flush it out with water. Certainly worth reading up on before trying it.
 
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