CLR Flush

-
pacuda59

pacuda59

pacuda59
Joined
Sep 20, 2005
Messages
5,790
Reaction score
813
Location
Pennsylvania
Yesterday I drained the coolant and replaced it with CLR and distilled water. I plan on leaving it in the car while it's parked this week. I'm assuming it will be pretty dirty when I drain it based on the condition of the antifreeze.

Question, should I plan on replacing the thermostat? What manufacturer and rating should I replace it with. I have a slant 6.
 
It is usually reommended to stay with the factory temp thermostat because if you change the temp of the engine you change the way it wears.
Running a different temp can cause different wear on the internals.
Just my oppinion on it.

Also, you may want to do a good blast flush on the engine after sitting with the CLR in it since it will allow stuff to come loose and fall down in the block and settle in the coolant passages.
If you have an air compressor you can use air and water to flush it.
Take the thermostat out and remove the bottom radiator hose.
Put your air line and water hose together and wrap a wet rag around them and push them tight against the thermostat inlet and let water start filling the block while giving it an occaisonal blast of air along with it (about every 10 seconds) hit the air.
Do this in both directions through the block alternating using the lower hose and the thermostat inlet.
It works really well for blasting the sediments out of the block, because the air pressure builds up behind the water and really forces it through the block fast.
My coolant looked pretty clean when I got my car and I have been cleaning blocks out like this for most of my life.
The first couple of blasts came out yellow with chunks and now the cooling system is nice and clean.
 
TrailBeast said:
It is usually reommended to stay with the factory temp thermostat because if you change the temp of the engine you change the way it wears.
Running a different temp can cause different wear on the internals.
Just my oppinion on it.

Also, you may want to do a good blast flush on the engine after sitting with the CLR in it since it will allow stuff to come loose and fall down in the block and settle in the coolant passages.
If you have an air compressor you can use air and water to flush it.
Take the thermostat out and remove the bottom radiator hose.
Put your air line and water hose together and wrap a wet rag around them and push them tight against the thermostat inlet and let water start filling the block while giving it an occaisonal blast of air along with it (about every 10 seconds) hit the air.
Do this in both directions through the block alternating using the lower hose and the thermostat inlet.
It works really well for blasting the sediments out of the block, because the air pressure builds up behind the water and really forces it through the block fast.
My coolant looked pretty clean when I got my car and I have been cleaning blocks out like this for most of my life.
The first couple of blasts came out yellow with chunks and now the cooling system is nice and clean.
Click to expand...

Thanks TrailBeast!
I've got one of those hose nozzles with the graduated nozzle for different size hoses. I probably haven't use it in 30 years. It also has a port for an air hose. I was planning on using it on the heater core but will take you suggestion and also use it through the empty thermostat housing. Based on your suggestion, I'm assuming I want to keep the gunk from the block out of the radiator and heater core.
 
pacuda59 said:
Thanks TrailBeast!
I've got one of those hose nozzles with the graduated nozzle for different size hoses. I probably haven't use it in 30 years. It also has a port for an air hose. I was planning on using it on the heater core but will take you suggestion and also use it through the empty thermostat housing. Based on your suggestion, I'm assuming I want to keep the gunk from the block out of the radiator and heater core.
Click to expand...

where'd you get this nozzle? my system could definitely use a coolant flush
even though it sounds mostly like this tool will gather dust :toothy10:
 
Here's a link to a similar nozzle at Amazon.

[ame="http://www.amazon.com/Thexton-THX356-Cooling-Systems-Backflush/dp/B0045CUMVG"]Thexton (THX356) Cooling Systems Backflush Tool - Amazon.com[/ame]
 
I just noticed that the nozzle listed in the link doesn't have the compressed air nipple like mine. There is one listed below this on on Amazon with the air nipple but it's double the cost. I'll see if I can hunt one down.
 
pacuda59 said:
Based on your suggestion, I'm assuming I want to keep the gunk from the block out of the radiator and heater core.
Click to expand...

Exactly.

If you do use it on your heater core, be gentle with the air, and be SURE you are blowing it backwards to flow the first rinse.

On the block direction does not matter since it does not have tubes that can be plugged up.
Just blast it both directions a few times.
 
If you take a wet hand towel and wrap it a time or two then put your air nossle next to the hose and wrap it up. it works pretty good without having to buy anything.
 
With the block, I remove the thermostat and use the upper thermostat hose for the first flush, flushing it out the disconnected lower radiator hose.. What port should I use for the reverse block flush?

Thanks again!
 
pacuda59 said:
I've got one of those hose nozzles with the graduated nozzle for different size hoses. I probably haven't use it in 30 years. It also has a port for an air hose. I was planning on using it on the heater core...
Click to expand...

I have used one of those power back flushing tools for years. One suggestion. Be very careful if you use it on the heater core or you may be replacing the core. These are 40 years old and some are very weak. I have ruined a couple of them by applying a burst of air pressure. Just use the hose pressure and you should be fine.

We always take out the thermostat and reinstall the radiator hose. Disconnect the other end at the radiator and insert the tool. Disconnect the lower hose and back flush the block first. Then reconnect the lower hose and flush again. This back flushes the radiator also. But do the block first so that you don't force all of the crap from your block into the bottom of your radiator.

Good luck!
 
I've never used the compressed air option on the nozzle and wasn't going to unless I ran into a clog. However, I'll take your advice about the heater core.

I think I've got it down....thanks guys!
 
Another question.....

This winter I'm planning on pulling the dash apart to repair gauges, replace the radio, replace the wiper gaskets and bushings and service the heater and vents. When I'm finished flushing, I'm planning on bypassing the heater core so I don't have to drain the system in the middle of the winter. Am I missing something? Can the heater core be left for the winter without fluid in it?
 
pacuda59 said:
Another question.....

This winter I'm planning on pulling the dash apart to repair gauges, replace the radio, replace the wiper gaskets and bushings and service the heater and vents. When I'm finished flushing, I'm planning on bypassing the heater core so I don't have to drain the system in the middle of the winter. Am I missing something? Can the heater core be left for the winter without fluid in it?
Click to expand...
I don't think it'd hurt it. If water was left in it over the winter, you might experience it freezing and bursting.
 
Over the past years I've replaced maybe three thermostats while working on various cars. I've never seen on in as bad condition as the one I pulled this weekend!
 

Attachments

  • Cuda.Thermostat.2.jpg
    40.4 KB · Views: 407
  • Cuda.Thermostat.3.jpg
    36.8 KB · Views: 404
  • Cuda.Thermostat.4.000.jpg
    51 KB · Views: 436
I was shocked when I saw the condition it was in.
Question.....Before I pulled it apart, I wasn't getting any heat. I assumed my heater core was blocked. After the flush and a new thermostat, I'm getting heat. I assume it failed in the open position. Would this have restricted flow to the radiator?
 
pacuda59 said:
I was shocked when I saw the condition it was in.
Question.....Before I pulled it apart, I wasn't getting any heat. I assumed my heater core was blocked. After the flush and a new thermostat, I'm getting heat. I assume it failed in the open position. Would this have restricted flow to the radiator?
Click to expand...

Failing in the open position should have made the heater flow and have heat unless the engine was not warming up enough because of it failing open.
That would explain it.
 
pacuda59 said:
...I assume it failed in the open position. Would this have restricted flow to the radiator?
Click to expand...
it's rotted through, nothing left but open :D you might have also had some blockage at the heater core that the flushing cleared up. i'd be expecting the core to fail in the next year or two...might want to just change it if your going to have half the dash apart anyway


good luck
 
Thanks.
If I were to replace my heater core, is there a certain manufacturer I should look for?
 
pacuda59 said:
Thanks.
If I were to replace my heater core, is there a certain manufacturer I should look for?
Click to expand...
i asked that here before and the answers were basicly whatever from a good parts store. well that's what i've always done, but there is alot of cheeper crap around now a days. anyway, the one i got from NAPA fit fine, except the hose fittings were not at the correct angle and i ended up repositioning them a little with help from a large spring on the inside. wasn't hard, just need to make sure you don't collapse or crack something
 
You must log in or register to reply here.
-

Back
Top