• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Block Flush, Need Advice

RRDon

Well-Known Member
Local time
1:44 PM
Joined
Jan 13, 2017
Messages
792
Reaction score
3,051
Location
Southern Utah
Well, I got tired of chasing the heating problem with my 383 RR so I bought a new Griffin direct fit radiator with elect fan. It worked great for about 30 minutes then I started having the same heating problem again at low speed and idle.
OK, so I found out what was causing the problem and here it is:
crap, I can't find the pic right now, I'll post it shortly. Anyway the problem is the radiator clogged with rusty dark looking debris, looks like small gravel but it's metal.
It's obviously from the block. What is the best way to flush the hell out of it?
 
Clogged Radiator 1.jpg
 
That's what I found when I drained the coolant and looked inside my BRAND NEW expensive aluminum radiator. Not a happy camper to say the least. Never noticed much of anything in the coolant when I drained the radiator on other occasions. I guess the radiator cores filtered it all out, :/
 
knock out the freeze plugs and flush the bottom of the block out. It May be tideious and difficult but it will remove most of the sediment that's accumulated over the years. pull the rad out and flush it too.
 
My grandpa SWORE by product called SANI Flush.
This is a plumbing product, I think, so check to make sure its ok with aluminum.
My grandpa started with union in 1948, and has tons of neat old school tricks.

I have used the SANI Flush on heavy equipment many times, but not on aluminum radiator.
Worked great in contaminated equipment cooling system.
 
Judging from the pictures, looks like there is a lot of junk in that cooling system. I always pop all the freeze plugs out take a pick and break up as much crap as possible then do a high pressure water treatment to loosen and flush as much out as possible.
 
Thanks but I was hoping to do this without pulling the engine. There's no way I can get those freeze plugs in and out with the engine installed. :/
 
Thanks but I was hoping to do this without pulling the engine. There's no way I can get those freeze plugs in and out with the engine installed. :/
I would at least pop out the ones that are easy to get to, and flush as much crap out as possible.
 
Cascade and a garden hose is gentle and cleans well. Start with two cups and idle until thermostat opens. Drain and repeat with one cup. Drain and rinse.
See how clear the final rinse water is and decide if you can go and fill with coolant.
 
Perhaps you may want to consider using an old time metal cleaning material call TSP or Tri Sodium Phosphate. This material is a granular white crystal compound that is dissolved in hot water and then the solution would be added to the engine's cooling system and circulated, then drained and thoroughly rinsed
From Google:
CleaningEdit
Trisodium phosphate was at one time extensively used in formulations for a variety of consumer-grade soaps and detergents, and the most common use for trisodium phosphate has been in cleaning agents. The pH of a 1% solution is 12 (i.e., very basic), and the solution is sufficiently alkaline to saponify grease and oils. In combination with surfactants, TSP is an excellent agent for cleaning everything from laundry to concrete driveways. This versatility and low manufacturing price made TSP the basis for a plethora of cleaning products sold in the mid-20th century.
The stuff is relatively inexpensive and available at large home improvement centers or perhaps Ace Hardware.
Just a thought....you should test the comparability with your aluminum radiator b4 use.
BOB RENTON
 
RRdon, I used this https://www.summitracing.com/parts/...z3SyFfwLOGRl2FjfBl30QlQK_73ZshN8aAvYWEALw_wcB
Its a engine , radiator flush made by evaporust. I got mine at wally world and used 2 qts. to do my 440 .
I over did it a bit but wanted it clean.
I first pulled the termostat & did a plain water flush to get rid of all the coolant. put the 2qts of evaporust/thermocure in and refilled with water.
Drove the car for a couple weeks off and on , few heat cycles prob 100 /150 miles or so.
When I drained it pulling the bottom hose I was supprised at the amount of crap that came out, It took 4 more complete flushs with straight water to get it running clear and clean.
 
Look for a cooling system filter that goes in line on the upper hose.
 
Most of the crap accumulates around the back cylinders. Even if you could pop the 2 rear frost plugs out and pressure wash in there youd be doing yourself a huge favor.
 
I've replaced literally hundreds of freeze plugs without removing the engine.... Some are easy & don't require removing anything, Some require taking off parts for access.... The starter, steering linkage, motor mounts.... On a big block in a Mopar B body they can all be changed in the car...

All the cleaners are good but at the end of the day debris in the cooling system tends to stay in the block cause it's heavy... Removing the freeze plugs allows the crap to drain out of a much lower point and instead of a small drain petcock you have a 1 5/8" hole....

And I agree the rear cylinders tend to have the most crap so if you only pop the rear plugs you'll get most of the crap... besides the stuff further forward will flow toward the rear...

Also when your done I agree about using a filter in the upper radiator hose for a few months just to be extra careful...

https://www.amazon.com/Champion-Cooling-Systems-CCHF-1-75-Coolant/dp/B01FYAEDGW
 
It looks like stop leak in there. You will need some chemicals to flush that crap outta' there. Hoe you can find something that plays well with the aluminum. I bet I spent 3 or 4 hours flushing out my block on the engine stand with all the plugs out. They didn't do a very good job shaking out the foundry sand from the water jackets.
 
BTW Your easiest way to hopefully flush the debris from the radiator is to pull it & back flush it by forcing a large volume of water through the lower hose connection.... A garden hose is marginal, a 1" or larger connection is better...
 
If the frost plugs haven't been changed in awhile they might be really thin looking at the scale caught it your radiator. So replacing with new ones might be a good thing in the long run.

Remove the radiator, turn it upside down and flush with water to remove the scale.

Remove the thermostat, frost plugs, block drains, heater hoses. Flush heater core backwards. Run water into the thermostat housing flushing out the block. Run water into the lower hose to flush block in that direction. Scrape around inside of each removed frost plug and rinse inside there.

You might want to do this on a hot day wearing your old swimming trunks!
 
If you install a filter, just run straight water for awhile till its finally cleaned a few times. That way you don't waste money on coolant.
 
Perhaps you may want to consider using an old time metal cleaning material call TSP or Tri Sodium Phosphate. This material is a granular white crystal compound that is dissolved in hot water and then the solution would be added to the engine's cooling system and circulated, then drained and thoroughly rinsed
From Google:
CleaningEdit
Trisodium phosphate was at one time extensively used in formulations for a variety of consumer-grade soaps and detergents, and the most common use for trisodium phosphate has been in cleaning agents. The pH of a 1% solution is 12 (i.e., very basic), and the solution is sufficiently alkaline to saponify grease and oils. In combination with surfactants, TSP is an excellent agent for cleaning everything from laundry to concrete driveways. This versatility and low manufacturing price made TSP the basis for a plethora of cleaning products sold in the mid-20th century.
The stuff is relatively inexpensive and available at large home improvement centers or perhaps Ace Hardware.
Just a thought....you should test the comparability with your aluminum radiator b4 use.
BOB RENTON
Great info! Thanks Bob. RRDon
 
My grandpa SWORE by product called SANI Flush.
This is a plumbing product, I think, so check to make sure its ok with aluminum.
My grandpa started with union in 1948, and has tons of neat old school tricks.

I have used the SANI Flush on heavy equipment many times, but not on aluminum radiator.
Worked great in contaminated equipment cooling system.

Running a large maintenance department, we had several outdoor crawler boom cranes (Link-Belt, Americian 500 and 700 series, Bucyrus-Erie 30B) all equipped with friction clutches for all motions, the clutch drums would get glazed to the point where the clutches will slip, even though they were adjusted to the proper clearances. The fix...a one or two large handfuls of dry Sani-flush tossed into the rotating clutch drums then applying the clutch several times cleaned the friction surfaces almost instantly. Also used Sani-flush on the steering clutches on Cat dozers. Just be careful when using it on aluminum or copper radiator tubes...its corrosive and may damage the netal (as in dissolving it).
BOB RENTON
 
Auto Transport Service
Back
Top