#1  
Old 08-10-2020, 04:17 PM
Tomslemans67 Tomslemans67 is offline
Senior Chief
 
Join Date: Sep 2005
Location: Monroe MI
Posts: 251
Default Cleaning coolant system

What is the best method for cleaning my cooling system on my 70 gto? I like to do this without the radiator being connected do to rust being in the coolant. Tom

  #2  
Old 08-10-2020, 04:37 PM
Chris65LeMans's Avatar
Chris65LeMans Chris65LeMans is offline
Ultimate Warrior
 
Join Date: May 2013
Location: Los Angeles, CA
Posts: 1,591
Default

FYI - I always had rusty coolant when I first bought my car. Then the heater core let loose a few years later, and it hasn't been a problem at all since.

I never flushed it without the radiator in place, so can't help you there.

__________________
1965 Pontiac LeMans. M21, 3.73 in a 12 bolt, Kauffman 461.
  #3  
Old 08-10-2020, 05:42 PM
694.1 694.1 is offline
Ultimate Warrior
 
Join Date: Jul 2010
Location: SE WI
Posts: 1,366
Default

If there are NO aluminum components...Timing cover could be an issue, Acid has no equal.
Phosphoric & Oxalic are great. Lime away might be a good start, even Vinegar would help, though you must neutralize acid.
Google is your friend.

__________________
"At no time did we exceed 175 mph.”
Dan Gurney's truthful response to his and Brock Yate's winning of the first ever Cannonball Baker Sea-to-Shining Sea...

Still have my 1st Firebird
7th Firebird
57 Starchief
  #4  
Old 08-10-2020, 06:13 PM
Stuart's Avatar
Stuart Stuart is offline
Moderator
 
Join Date: Apr 2003
Location: Minneapolis
Posts: 7,938
Default

Any auto parts store sells radiator flush products.

  #5  
Old 08-10-2020, 06:57 PM
694.1 694.1 is offline
Ultimate Warrior
 
Join Date: Jul 2010
Location: SE WI
Posts: 1,366
Default

"Any auto parts store sells radiator flush products. "

Actually, NO auto parts store still carries the old 2 part acid & neutralizer, that was discontinued at least a decade ago. Modern flushes will not touch rust.

__________________
"At no time did we exceed 175 mph.”
Dan Gurney's truthful response to his and Brock Yate's winning of the first ever Cannonball Baker Sea-to-Shining Sea...

Still have my 1st Firebird
7th Firebird
57 Starchief
  #6  
Old 08-11-2020, 12:10 PM
Tomslemans67 Tomslemans67 is offline
Senior Chief
 
Join Date: Sep 2005
Location: Monroe MI
Posts: 251
Default

Actually I have the product to clean the system. But trying to figure a way to clean it without the radiator being in the car do to it being new and don’t want all that old crap flowing threw it. Tom

  #7  
Old 08-11-2020, 06:06 PM
Joe's Garage Joe's Garage is offline
Chief Ponti-yacker
 
Join Date: Oct 2016
Location: Las Vega$, NV
Posts: 637
Default We've used an old radiator to do this in the past.

When there was a lot of rust in the block and a fresh radiator, we installed an old radiator - even a leaker - and then run the chemical cleaners thru the whole system to get the rust loose.

Since you normally need to run the engine to activate the cleaner, there isn't really any other way without removing the engine and having the bare block cleaned at a machine shop. Lots of work to do that.

Usually we did it once, then flushed and did it again with the cleaner. Twice as much cleaner and twice as long to get things twice as clean.

After the two cleaning 'cycles', we flushed really good a couple times with clear water and put the new radiator back in and fill with coolant and distilled water.

YMMV. Good luck.

  #8  
Old 08-11-2020, 08:48 PM
burd's Avatar
burd burd is offline
Ultimate Warrior
 
Join Date: May 2011
Location: MOTOR CITY
Posts: 1,526
Default

Just replace the nasty radiator.

__________________
🧩 Burds Parts, Finding those Hard to Find PCs, no Fisher Price Toys Here

Just Say No To 8” Flakes

F ire B irds

🇮🇱
  #9  
Old 08-12-2020, 01:20 AM
Joe's Garage Joe's Garage is offline
Chief Ponti-yacker
 
Join Date: Oct 2016
Location: Las Vega$, NV
Posts: 637
Default Re-read post #6

OP says the radiator is NEW and that is why he doesn't want to run cleaner thru it, along with all the rust and crap it will break loose.

  #10  
Old 08-12-2020, 01:39 PM
Longs's Avatar
Longs Longs is offline
Senior Member
 
Join Date: Jun 2000
Location: Pittsburgh, PA USA
Posts: 178
Default

You'd need to watch the temperature, but what about just connecting the upper and lower radiator hoses using a section of pipe, allowing the coolant to circulate as normal? I'd think that you'd want to remove the thermostat and reinstall the housing without it first, so that the engine didn't heat up quite as rapidly, but it would likely still heat up pretty fast. Just a question of whether you could run it long enough. Of course, you could do this, let it get hot, then just turn it off and let it sit for a while, then drain it. Do it a few times, then flush it out well with clean water and reinstall the radiator.

I have used a piece of pipe connected to the lower radiator hose to "back flush" my radiator, disconnected the upper hose, ran water in through the bottem radiator outlet and let it flow backwards up and out of the filler neck.

  #11  
Old 08-23-2020, 03:28 AM
lust4speed's Avatar
lust4speed lust4speed is offline
Ultimate Warrior
 
Join Date: Jul 2002
Location: Yucaipa, SoCal
Posts: 8,684
Default

Well, that's the normal flow path into the block from the bottom and out the top, but still a good idea. Removing the thermostat helps a lot also. Basically the more flow from either end will help dislodge crap. If the engine has had the two block drain plugs replaced recently, removing them and sticking a probe in the hole if necessary to get a clean flow of water will remove a bunch of sediment since the drain holes are basically on the bottom of the coolant area on each side of the block. Reason I said "recently" is we always remove them before sending bare blocks off to be cleaned and it's surprising how many times the plugs have never been removed even when there is evidence the block had been had been worked on before. Original plugs were metal that corrodes away over time and a few have broken off flush when attempting to remove them - and not something you want to get into when just going for a simple flush.

__________________
Mick Batson
1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 2+2 survivor AC auto -- 1965 Catalina Safari Wagon in progress.
  #12  
Old 10-24-2020, 12:26 PM
Longs's Avatar
Longs Longs is offline
Senior Member
 
Join Date: Jun 2000
Location: Pittsburgh, PA USA
Posts: 178
Default

I replaced my coolant yesterday, since it had been five years. I ran the Prestone Flush for a few days then drained and started replacing with water. After a few times draining the radiator and it seeming like I'd never get all the old coolant out, I took a different approach. With the thermostat still installed, I disconnected the top hose at the radiator inlet and attached a section of PVC pipe so that it extended over the front of the car where I could put a catch container on the ground in front of the car. I used duct tape to cover the radiator inlet so that I could pour water into the filler neck without it running out of the inlet.

I filled up the radiator, then filled up several old antifreeze bottles with hot water and brought them to the car. Started the car, and because the thermostat was closed, just a little trickle of water out of the PVC pipe. As the car heated up and the thermostat opened, water started coming out of the PVC pipe, and as the water level went down in the radiator I kept adding hot water. The water wasn't as hot as the 180 thermostat so it would occasionally close then reopen. I kept repeating this process until I'd run about 10 gallons of water through the engine and the water was completely clear.

I then disconnected the lower hose at the water pump and attached the PVC pipe so that it was straight up, higher than the filler neck. I then poured a couple of gallons of hot water into the PVC pipe so that it back flowed out the filler neck, running the water in from the bottom to the top of the radiator just to dislodge anything that might be stuck in the tubes.

I then reconnected the hoses and filled with 2-1/2 gallons of Prestone "All Vehicles" green coolant, which is supposed to be good for up to 10 years and 300,000 miles. Prestone's website recommends the "American Vehicles" product, which is apparently orange, or the "All Vehicles".

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:01 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017