Flushing Radiator

[khoi911]

I plan to replace my leaking radiator soon but before doing so I want to flush out the cooling system. I have done lots and lots of reading on this site and there is plenty of great info. From this info I have devised a plan and want to run it by the experts on this site as I am no expert.

1st of all I want to keep it as simple as possible without any fancy rigs/setups but I do want to do my best to get out the old fluid.

1a - Drain the radiator via the petcock.
1b - Drain the engine block but I'm not sure if I'm able to get fluid back in because at idle the engine never gets above the 180 degree mark required for the thermostat to open. (from my research on this site)
2 - Refill radiator with distilled water
3 - If I do NOT do 1b then I will drive her so she can warm up above 180 so the distilled water in the radiator flows into the block.
4 - Repeat 1a, 2 and 3 and flush 5 times.
5 - Installed new radiator and fill radiator with Coolant. (anyone know the capacity of the radiator itself?)

It seems flushing the engine 5x is extreme (I plan to have 20 gallons of distilled water on hand) but I think the more you can flush the better it is for removing dirty coolant from the heater cores without tapping into those lines.

Also been doing some research to keep my garage floor nice and clean while draining fluid and my solution is a feed bucket. I purchased one from a tractor supply store and they are big enough to catch most of the liquid (2 feet x 4 feet x 10 inches tall ... capacity is 15 gallons)

Any feedback is greatly appreciated. Thank you.

 

[corsair23]

I1a - Drain the radiator via the petcock.
1b - Drain the engine block but I'm not sure if I'm able to get fluid back in because at idle the engine never gets above the 180 degree mark required for the thermostat to open. (from my research on this site)
2 - Refill radiator with distilled water
3 - If I do NOT do 1b then I will drive her so she can warm up above 180 so the distilled water in the radiator flows into the block.
4 - Repeat 1a, 2 and 3 and flush 5 times.
5 - Installed new radiator and fill radiator with Coolant. (anyone know the capacity of the radiator itself?)

Also been doing some research to keep my garage floor nice and clean while draining fluid and my solution is a feed bucket. I purchased one from a tractor supply store and they are big enough to catch most of the liquid (2 feet x 4 feet x 10 inches tall ... capacity is 15 gallons)

Any feedback is greatly appreciated. Thank you.

I don't know if a '94 and a '97 have any major design differences on the radiator but I don't believe so. As I recall, there is a small hose leading from the top of the radiator to the top of the engine. When you are refilling the radiator, have the front of the 80 up in the air (pointing up the driveway, up on ramps, up on jack stands, etc.) and refill slowly...Water/coolant will flow into the block via that tube and this also helps with "burping" the system of air. Also make sure your overflow is full of distilled water before running around and getting the engine hot in case you are low on fluid.

Good idea on the feed bucket to catch the old coolant...I'd add some newspaper, old towells, etc. around the area. One tip I found is to drain the radiator first (put a section of hose on the outlet to help direct the coolant into the bucket). Then when you go to pull the engine block drain leave the radiator cap on, pull the plug, and then slightly release the radiator cap. If you release the radiator cap seal completely you will have a heck of a mess (DAMHIK )

As for radiator capacity I don't recall the exact number off the top of my head (might be in the FAQs) but IIRC I used about 2 gallons of Toyota red coolant mixed 50/50 with distilled water and had some left over. So somewhere under 4 gallons. Put in 1 gallon of coolant, 1 gallon of distilled water, and then mix the last gallon of coolant 50/50 and top off. If you notice your temps are hotter than before you probably have too high of a mix of coolant. I did and the way I fixed that was to dump what was in the overflow bottle, refill with straight distilled water, run the truck for a day, check the mix, and repeat as needed until I achieved my desired 50/50 mix. My temps came down 5-10F from a 60+/40 mix to a 50/50 mix.

 

[coax]

1a - Drain the radiator via the petcock.
1b - Drain the engine block but I'm not sure if I'm able to get fluid back in because at idle the engine never gets above the 180 degree mark required for the thermostat to open. (from my research on this site)
2 - Refill radiator with distilled water
3 - If I do NOT do 1b then I will drive her so she can warm up above 180 so the distilled water in the radiator flows into the block.
4 - Repeat 1a, 2 and 3 and flush 5 times.
5 - Installed new radiator and fill radiator with Coolant. (anyone know the capacity of the radiator itself?)

It seems flushing the engine 5x is extreme (I plan to have 20 gallons of distilled water on hand) but I think the more you can flush the better it is for removing dirty coolant from the heater cores without tapping into those lines.

Also been doing some research to keep my garage floor nice and clean while draining fluid and my solution is a feed bucket. I purchased one from a tractor supply store and they are big enough to catch most of the liquid (2 feet x 4 feet x 10 inches tall ... capacity is 15 gallons)

Any feedback is greatly appreciated. Thank you.

When I replaced my radiator, I didnt want to do the coolant flush through the old rad with all sorts of deposits. To get around that, I removed the original rad (with original coolant left inthe block). Canabalized a set of old heater hoses, and using some pvc pipe between upper and lower intake/outlets from teh block, bypassed where the radiator was. This allowed me to do full flush w/ garden hose without loosening stuff in the old rad.

After I did the multiple direction garden hose flush, as well as draining out of the block (tons of deposits from there), I put the new rad. in, but without the thermostat.

Did the distilled water flush after running the engine for a few minutes to circulate water. Drain block, drain rad, repeat until I had gone through a number of gallons of distilled water.

Once I was ready for actual coolant, I installed the new thermo, and then did the "point uphill, run, etc"

Definitely do the garden hose flush...I got tons of junk out doing it that way rather than just a drain/fill process. Just dont go full blast if you have high domestic water pressure

hth

 

[grizzlygibbs]

That sounds interesting coax! I like it.

IIRC I flushed my rad I think 2 or 3 times wih tap water before flushing another 1 or 2 times with distilled. Definitely flush that block everytime you run the rig!

Also if your old rad is anything like mine, your petcock won't budge. I flushed from my bottom rad hose.

 

[gotmud]

You can eliminate a lot of the trapped air by removing a heater hose at your diverter valve. This is more or less the highest spot in your cooling system. This will help with Step 1b.

 

[96r50]

This seems to be a topic that commonly gets blown out of proportion (IMO), possibly because of the headgasket stigma associated with the cooling system. In essence, it should be a pretty simple process: drain out all the old coolant, flush the open system with clean water, replace any parts you want to, and refill the system with coolant.

The way I do it:
-Turn key to ON, and slide the heater temperature control to HOT. Remove key
-Remove the radiator petcock and drain the rad with the rad cap on (minimizes mess)
-Remove the block drain plug and drain the block
-If you want to get fancy, remove the thermostat. Also a good time to remove any of the parts you are replacing (radiator, water pump etc)
-Remove the metal U-shaped pipe on the firewall
-Flush the system with a garden hose, through the radiator cap opening and the two hoses on the firewall, until the water runs clear. Don't forget to remove the overflow tank and wash it out.
-If you got fancy, replace the thermostat as well as any other parts you took off
-Replace the block drain plug and the radiator petcock.
-Start refilling the system with straight coolant. Two full jugs (3.7L or 1gal each) in the system will give you a 55% coolant mixture if you have a rear heater (3.7x2=7.4L of coolant. 7.4/13.4=55%), or 60% if you have bypassed it at the firewall (7.4/12.5=60%). Mix a bit of the coolant 50/50 with distilled water and fill the overflow to the COLD line.
-Top off the radiator with distilled water and put the cap on
-Finish filling the last little bit of the system through the two hoses at the firewall, and replace the metal pipe.

At this point the cooling system should be completely back together and full, so run the engine for a few minutes to mix the coolant and water and to cycle the thermostat. Putting a piece of cardboard/plywood/garbage bag in front of the grill should speed up the process a bit (less airflow through the rad).

C'est tout!

 

[elhombre]

Mr. T sells the thermostat gasket by itself. I would suggest getting a brand new thermostat along with 2 or 3 extra thermostat gaskets. This way the next time you want to flush the system only and put in new antifreeze, you can pull the thermostat out of the housing and drain the block from both sides (use the block plug on the driver's side). I have done this 2 times in the 4 years and the first gasket has held up fine, but I do have an extra just in case it rips a little.

It does seem that when I pull the thermostat, all the fluid trapped in the water pump is able to escape. I also don't have to wait for the engine to warm up to get the flush water to move through the rest of the engine during the "cleaning" stage.

Personally, I think flushing with distilled water the first few times is only necessary if your on mucked up well water or terrible city water. Don't get me wrong, I am admittedly more neurotic than most about my cruiser, I just think using the distilled water for the last time before final fill is enough.

 

[khoi911]

-Remove the metal U-shaped pipe on the firewall

C'est tout!

Anyone have a pic of the U-shape pipe on the firewall?

 

[96r50]

You can't miss it, I promise

But just in case...

 

[khoi911]

You can't miss it, I promise

But just in case...

awesome! Thank you sir.

 

[option13]

Hi, Everyone.

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What's this..... an advertisement?

 

[Fireguy]

This seems to be a topic that commonly gets blown out of proportion (IMO), possibly because of the headgasket stigma associated with the cooling system. In essence, it should be a pretty simple process: drain out all the old coolant, flush the open system with clean water, replace any parts you want to, and refill the system with coolant.

The way I do it:

-Remove the metal U-shaped pipe on the firewall
-Flush the system with a garden hose, through the radiator cap opening and the two hoses on the firewall, until the water runs clear. Don't forget to remove the overflow tank and wash it out.

C'est tout!

Could you explain this a little more, I'm having trouble visualizing it. So you have the hose flowing into the radiator, and the water is coming out of the U shaped hose above the engine? Or are you also hooking a hose up to the U shaped hose? Which part of the U shaped hose do you disconnect? Thanks for your help!

 

[96r50]

I completely remove the U pipe.

I do all the flushing with the radiator petcock and block drain plug still out. I hold the garden hose in the radiator opening and it drains out the open petcock. Holding it to the lower of the two rubber hoses at the firewall will flush through the heater cores and into the thermostat housing/block. Holding it to the top firewall hose will flush through the PHH, into the head and out the block drain. I flush each one until I am getting clean, clear water coming out the drains.

 

[jlm43]

Just want to say thanks to all for the info. I am doing the PHH and a flush this afternoon and this info is a great help.

 

[NorCalDoug]

You can't miss it, I promise

But just in case...

do you have a recent shot of that u pipe? just outta curiosity...what did you use for the clamps?

 

[CrackerBob]

I plan to replace my leaking radiator soon

The radiator on my '93 is leaking as well. I replaced the radiator on my '96 lx450 a few months ago with a KOYO from ebay and it seems to be doing fine. Any reason this same radiator wouldn't fit my '93 LC? Seems like it should, but figured I'd ask the experts here first.

1996 1997 Lexus LX450 KOYO Radiator A1918 4.5 L6: eBay Motors (item 380228469364 end time May-27-10 09:47:19 PDT)

 

[NorCalDoug]

The radiator on my '93 is leaking as well. I replaced the radiator on my '96 lx450 a few months ago with a KOYO from ebay and it seems to be doing fine. Any reason this same radiator wouldn't fit my '93 LC? Seems like it should, but figured I'd ask the experts here first.

1996 1997 Lexus LX450 KOYO Radiator A1918 4.5 L6: eBay Motors (item 380228469364 end time May-27-10 09:47:19 PDT)

don't know about the Koyos, but I can definitely state, with the utmost certainty, that the OEM radiators for the 93/94 Land Cruisers are an exact drop-in match with the 97 LX 450s...

I just completed a radiator swap in my wife's LX today (thanks CDan! ). No issues...except for the FSM stating that the fan shroud bolts needing to be torqued to well beyond the breaking point of the shroud plastic )


So...to answer your question...yes, it should fit fine.

 

[96r50]

do you have a recent shot of that u pipe? just outta curiosity...what did you use for the clamps?

I'm not sure what you're looking for exactly, but here are the only other shots I have of that area.

Zoomed out

The pipe and the old hoses and destroyed clamps.

These pics are from a few years ago. I replaced the two hoses with the silicone Firewall Heater Hose kit that I had ordered from 1FZFEPHH along with my PHH. I removed my rear heater last year and bypassed the lines at the firewall so the bottom hose is now one piece of rubber hose from the bottom of the U pipe to the front heater core nipple on the firewall. If you want more recent shots I can take some later today.

 

[primer7]

Where is the block drain located?

 

[96r50]

Where is the block drain located?

Pretty crummy pics, but this is the driver's side of the engine, just aft of the shock tower. 14mm socket IIRC.