Radiator trans cooler leak takes out transmission. How to clean cooling system?

Messages
5,451
Location
Suburban Washington DC
Chevy Spark with over 100,000 miles. Fluid in overflow tank looks a chocolate milkshake. Chevy dealer says trans cooler leaked allowing coolant into transmission. I'll get a low mileage transmission for $300 and a new radiator for $100. What's the best way to clean out the transmission fluid from the cooling system? I was thinking, take out the radiator from the circuit as well as remove the thermostat temporarily and somehow connect the two radiator hoses together. Add some water based solvent and run the engine a few minutes. Drain and repeat. Do they make a specific solvent for this purpose? Any other ideas?
 
Messages
5,242
Location
Fort Worth, Texas
Dawn dish soap is the cheapest effective solution I've found. There are much better, albeit expensive industrial water based concentrates.......Certified Labs "GRRR" is one of the best I've used.
 
Messages
1,679
Location
RI
There is a product made for diesels endorsed by Cummins called Restore. It's made by Fleetguard. It can be used in gas engines too. It does an excellent job of removing any oil based fluid from the cooling system as well as grease and silicates.
 
Last edited:
Messages
21,863
Location
Apple Valley, California
Originally Posted by rubberchicken
Originally Posted by Chris142
Dishwashing detergent.
I am thinking this might not be the best method, due to foaming. Prestone has a different product than the traditional radiator cleaner, but I have not used it before- https://prestone.com/products?detail=AS110Y
The powder wont foam much plus the pressurized cap helps prevent foaming. Leave the old radiator in but bypass the cooler for now. Put the detergent and water in it. Run it,drain repeat till clean then put your new radiator in.
 
Last edited:

atikovi

Thread starter
Messages
5,451
Location
Suburban Washington DC
Originally Posted by Chris142
Originally Posted by rubberchicken
Originally Posted by Chris142
Dishwashing detergent.
I am thinking this might not be the best method, due to foaming. Prestone has a different product than the traditional radiator cleaner, but I have not used it before- https://prestone.com/products?detail=AS110Y
The powder wont foam much plus the pressurized cap helps prevent foaming. Leave the old radiator in but bypass the cooler for now. Put the detergent and water in it. Run it,drain repeat till clean then put your new radiator in.
OK, just thought I'd be that much ahead by taking the contaminated rad out of the picture from the start.
 
Messages
665
Location
WA
Water and dawn. Lots of it. Probably going to have to drain/fill the thing half a dozen times to get rid of the oil then another half dozen to get the soap out. From there, flush it with distilled water or leave it depending on how picky you are. Measure how much you remove during the final drain then compare w/ rated capacity to see if you need to pop a freeze plug out to get enough displacement to add the appropriate amount of concentrate for your desired ratio.
 
Messages
9,032
Location
Marshfield , MA
ATF in the coolant is just a mess. Nowhere near as bad as water in the ATF. It will dissolve the glue in the clutch packs. Using an external cooler, is all you need, Blow out the lines and the torque converter I would use Dawn because it will work and will be way easier on your hands as you flush etc. A back flushing tee in the heater outlet would be a plus too. Please post results.
 
Last edited:
Messages
643
Location
Florida
This is bringing back memories. Sorry to hear about your problem. I recently had this happen to me and learned a lot from this forum's help. I think I was fortunate to save the transmission and coolant did not get back into the transmission...plenty of transmission fluid in the radiator though. I captured a sample of the transmission fluid from the transmission cooler lines and coolant from the radiator drain plug, put samples in glass jars and watched them separate over time. White lid is coolant sample, black lid is transmission sample. Took sample to transmission specialist in my area and he said even the slightest amount of coolant in the transmission fluid would change the fluid color and ruin the transmission in short time. He said I was good to go. [Linked Image] Did you lose the transmission, or do you think you lost the transmission because there was transmission fluid in the coolant? With the thermostat removed, I flushed out as much of the old contaminated coolant as possible from the upper hose and out the bottom hose into a bucket. Installed the new radiator and ran a cycle of distilled water through system. Drained, and removed all remaining fluid by venturi cooling system vacuum. Refilled with distilled water and Prestone radiator flush and degreaser. Followed procedure. Radiator flush and oil degreaser Another couple drains and refills and venturi vacuum of system with distilled water. Cooling system is looking pretty clean now. When I am done with other work that has arisen from this problem, I will refill with 50/50 coolant. Other problems - Had to replace hoses and seals because the transmission fluid compromised them. One leaking seal in particular was feeding a heater core tube under the intake manifold, so I needed to remove intake and water pump to get to it. It was leaking fluid on top of my block under intake. Replacing water pump (seal originally, but decided to do pump since it was cheap and already off), replace t-stat and t-stat gasket, lower radiator hose seal came with new radiator. Then drain torque converter, drain transmission fluid, remove and replace filter, refill transmission system. Good luck and pay attention to those hoses and seals...they are relatively inexpensive, so probably a good idea to change them anyways and watch out for extra holes in the ends of the hoses where they pierce for hanging straps, find a source where they use clips to hang instead of poking holes in hoses.
 
Messages
12,148
Location
OH
Originally Posted by atikovi
Chevy Spark with over 100,000 miles. Fluid in overflow tank looks a chocolate milkshake.
Is this the 2017 Spark that you traded recently for the Jeep?
 
Top