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corsair23
04-23-2008, 02:41 PM
Ok...I'm about half braindead and I need some help :o

I have drained the coolant (block and radiator), replaced the majority of the hoses including the PHH and FHHs, and replaced the thermostat. My next plan was to refill the cooling system with distilled water, run the rig, drain the block and radiator again, repeat the process one more time, and then refill with coolant/water and call it good.

I read the FSM and it just says to refill the "system" and then makes a mention of bleeding the system :confused:. Obviously the FSM is written for people that have a little more background than I do and understand how to do some of the simpler things in life like bleeding the system. I did a google search and a search here and on MUD and came up empty for the most part.

So, for the 80s experts, do I just refill the system at the radiator knowing full well that I can't truly "fill" the system that way due to the thermostat not being open until the truck hits 180+ degrees and top it off after it cools? How do I "bleed" the system :confused:.

I was going to do the Prestone flush kit dealyo but that is hard to do when the truck is still on jack stands in the garage :o so I figured this was probably my best option right now.

TIA

subzali
04-23-2008, 03:18 PM
I think what it takes is running the system hot - it will pull more coolant into the system as it heats up. That's about all I got, I tried it and it worked for me, don't have any overheating problems and haven't had to add any coolant to the overflow bottle for a while.

Uncle Ben
04-23-2008, 05:24 PM
FZJ's have a bleed hose on the upper (return) water neck. There is no bleeder. As you fill the highpoint will bleed the trapped air into the top tank. Just fill slow and it will fill. Running it after you get it mostly full with the heat control turned up will purge the air from the front and rear heater lines. Normally, the way to bleed is to allow the highest point of the system to purge air. Vehicles that have problems with trapped air usually have the top tank of the radiator lower than the head of the engine.

corsair23
04-23-2008, 05:41 PM
Thanks guys!

UB, so would suggest running the rig with the radiator cap off and once the engine gets to operating temp and the thermostat opens to just keep filling? I know the radiator is full but I'm assuming that right now I have no water in the block which makes me wonder how the heck the thermostat is going to open when there isn't any heat to cause it to do so...maybe I'm just overthinking the whole thing :D - Not like that has never happened before :lol:

Uncle Ben
04-23-2008, 06:08 PM
Thanks guys!

UB, so would suggest running the rig with the radiator cap off and once the engine gets to operating temp and the thermostat opens to just keep filling? I know the radiator is full but I'm assuming that right now I have no water in the block which makes me wonder how the heck the thermostat is going to open when there isn't any heat to cause it to do so...maybe I'm just overthinking the whole thing :D - Not like that has never happened before :lol:

How much coolant/water did you put in? My guess is it's full (engine and radiator).

corsair23
04-23-2008, 06:17 PM
How much coolant/water did you put in? My guess is it's full (engine and radiator).

Right now it is just distilled water...Since I can't do a true flush with a hose I'm going to run distilled water through and drain it a couple times in hopes of getting 90% of the old stuff out.

I was able to get just under 3 gallons of water in via the radiator. The FSM states the system holds 14.7 liters which is ~3.9 gallons so it is probably more full than I think :rolleyes:...Especially considering that you probably can't truly get ALL of the old stuff out in the first place.

Looking at it now (the FSM diagram) and trying to understand what you stated, the water is probably backfilling into the engine block via the radiator inlet hose huh? The one on the top right of the radiator?

I guess after reading E9999's write up on MUD I figured it really couldn't be as easy as it was looking :doh:

Uncle Ben
04-23-2008, 08:38 PM
Right now it is just distilled water...Since I can't do a true flush with a hose I'm going to run distilled water through and drain it a couple times in hopes of getting 90% of the old stuff out.

I was able to get just under 3 gallons of water in via the radiator. The FSM states the system holds 14.7 liters which is ~3.9 gallons so it is probably more full than I think :rolleyes:...Especially considering that you probably can't truly get ALL of the old stuff out in the first place.

Looking at it now (the FSM diagram) and trying to understand what you stated, the water is probably backfilling into the engine block via the radiator inlet hose huh? The one on the top right of the radiator?

I guess after reading E9999's write up on MUD I figured it really couldn't be as easy as it was looking :doh:


The top hose is return to the radiator. Heat rises! Unless you drain the block you could not get all the coolant out and even then there will still be a couple quarts hiding in there. If you can't put anymore water in the radiator the system is full! If you haven't run it there might be a couple stray pockets of air but the top tank of the radiator is the highest point in the cooling system and like I said it has a bleeder line on the top of the return pipe before that pipe drops back down to clear the distributor. Not rocket science man.....just a high tech tractor motor!

nakman
04-23-2008, 10:53 PM
Dude if you put 3 gallons of water in there start the truck- full enough!

corsair23
04-23-2008, 11:13 PM
Dude if you put 3 gallons of water in there start the truck- full enough!

:lmao: - Yeah, overthinking it as usual. Thanks as always to UB for explaining things in a way even I can understand :thumb:

Ran it tonight for about 15 mins with both heaters running full bore, then let it cool and drained the radiator and block again. During that time I was able to get the new rotors and hubs back on and pretty much buttoned up ready for the new brake pads. I'll fill the rig up again tomorrow with more distilled water, run it, drain it, then fill it with coolant/water and call it good and try to finish up the brakes and hopefully have it back on the road Friday :rolleyes:

Corbet
04-25-2008, 05:00 PM
I'm a little late to the discussion but I like to park the vehicle on a slight incline with the radiator up just to help a little extra.

This funnel kit is also a great little helper for getting the air pockets out. Especially on Subaru's as they are a pain to "burp"

http://www.drivewerks.com/catalog/ShopCart/TOOL/POR_TOOL_CAT591_pg2.htm

I got mine locally at CarQuest.

corsair23
04-25-2008, 05:44 PM
Thanks Corbet...

The LX is sitting slightly nose high in the garage on jack stands...However, when I do the final fill I plan to park it in the driveway to give it a little more nose high attitude :thumb: