2H Radiator flush or rinse?

[Skidaho]

Slowly going through my Troopy and changing fluids and cleaning things up. I've never flushed a radiator... nor drained one. When I took the radiator cap off it was pretty dirty inside... like baby diaper diarrhea dirty.

2H has never run hot and I have not had a cooling issue... but thought it might be a good idea to get the radiator flushed and cleaned.

Heres my questions:
1. Will flushing the radiator "stir things up" where it might cause some cooling problems?
(I was going to have my local diesel shop flush it for me)

2. Do I need to put a new thermostat in when I flush the radiator?

3. The radiator overflow bottle... is it supposed to be to the "full" line with water or mixture of water and anti-freeze? (It it down at the "low" line and full of sludge)

Thanks for the help.

Thermostat is not leaking... but looks like it is sweating.

 

[jzilla]

That looks pretty dirty, definitely flush it out. Make sure they also flush the engine block completely through the engine block coolant drain (not sure where it is on the 2H). Yes you might cause some issues flushing (may find leaks in rad or heater core), but better to find the issues now then when you are on the road. You should have the whole cooling system flushed (engine and heater core). If it were me I would install a new thermostat and gasket.
Replace any old coolant hoses while you are at it. Also make sure your block heater works if you have one. The overflow tank should have the same mixture as the rest of the system (generally 50/50). It is good practice to use distilled water when mixing with antifreeze. Keep the overflow tank at the max line.
Good luck!

 

[jzilla]

Just had a thought...ask the shop how they flush.
Some places will just drain and refill with water and run the engine and drain it and repeat until the water is clean.
I used to work for a radiator shop...when they flushed things they did it with a water/air pressure gun, this thing would really blast the system out. If the radiator was off the vehicle the same tool would be used. Flushed in the reverse direction of normal flow.

 

[Skidaho]

Jzilla - thanks for the info. I will do that in the morning when I talk to the shop.

 

[aaron9252]

Reviving this thread, can anyone tell me where the engine block plug is to drain the radiator fluid?

A picture would be very helpful.
I just pulled my radiator and I’m taking it to a shop to have cleaned/pressure tested. Before putting everything back, I’d love to completely drain the current fluid and then replace with toyota red.
Thanks

 

[duncanrm]

Reviving this thread, can anyone tell me where the engine block plug is to drain the radiator fluid?

Here's a video I did of flushing a 2H block and heater core.. you will have to do this multiple times to get that muck out.. If yours is an HJ60 consider a rear heater delete at the same time. Make sure your heater tap is on when you do this.

 

[aaron9252]

Here's a video I did of flushing a 2H block and heater core.. you will have to do this multiple times to get that muck out.. If yours is an HJ60 consider a rear heater delete at the same time. Make sure your heater tap is on when you do this.

Thanks! That’s perfect.

 

[hj 60]

When I removed the thermostat the bolts broke:

The crap kept coming out,maybe stop leak stuff, repaired cracked seal and after 30 kilometers it broke again, replaced with new rad:

rad drain valve is plastic and if it is to tight I would not like to break it:

This type clamp failed me 3 times with new rad hoses, they popped of just before a 4000km trip, never again, only the NON STAINLESS!! (=to soft metal) wrench clamps:

engine drain:

few more pictures here: Radiator, cooling, heater DEFA 411122 30mm 600W

 

[Touz]

Here's a video I did of flushing a 2H block and heater core.. you will have to do this multiple times to get that muck out.. If yours is an HJ60 consider a rear heater delete at the same time. Make sure your heater tap is on when you do this.

Hi Duncanrm,

I am trying to flush out my coolant with the radiator removed. I did the same as in your video but the coolant isn't flushing out from the lower pipe that was connected to the radiator. It is coming out of the engine drain plug. What gives? I can't why having the radiator removed would make a difference?

 

[duncanrm]

Hi Duncanrm,

I am trying to flush out my coolant with the radiator removed. I did the same as in your video but the coolant isn't flushing out from the lower pipe that was connected to the radiator. It is coming out of the engine drain plug. What gives? I can't why having the radiator removed would make a difference?

Shut off the block drain and see what happens?

 

[sodafeld1]

I like to reverse flush too when the radiator is out, even the water pump removed. A squeeky clean cooling system is optimal. New thermostat and hoses.
Some points to add; a local ratrod radiator specialist (also ex olympic shot putter!) down the road from me admitted he rarely used the drain on the block, give it a good flush both ways inlet and outlet from the radiator hose connections.

Mercedes also recommends using dilute citric acid slightly warmed to help remove gunk. You can get it from merc or a 5th the price from a cake supplies shop. It is fairly gentle acid, but it can help does not damage rubber apparently.

As Duncan said , have the heater on as there is a little radiator in the cabin, that needs flushing too.

Anti freeze/coolant has rust inhibitors, pretty good stuff we can get now a day last 8 years. So if you your cooling system is clean, it stays clean. Distilled water is meant to be better to add to the concentrate, as the minerals are removed, some tap water has lime etc..

Gosh still can't get my head around aluminium radiators, copper is a far superior material imo. Aluminium is cheaper for the manufacturer, they are starting to replace some electrical wiring with aluminium due to it being cheaper. But no way in my mind is it able to outlast fatigue and bouncing around as copper. Can burn out grass seed on copper too with a gas torch, plug a leak with with lead, not aluminium.

It does not make sense water comes out the engine unless from the drain on the block. Trickling down the side?

 

[Touz]

Shut off the block drain and see what happens?

Thanks for the suggestion. I tried that but no difference. I think the problem might be that the pressure from hose is very low.

 

[Touz]

I like to reverse flush too when the radiator is out, even the water pump removed. A squeeky clean cooling system is optimal. New thermostat and hoses.
Some points to add; a local ratrod radiator specialist (also ex olympic shot putter!) down the road from me admitted he rarely used the drain on the block, give it a good flush both ways inlet and outlet from the radiator hose connections.

Mercedes also recommends using dilute citric acid slightly warmed to help remove gunk. You can get it from merc or a 5th the price from a cake supplies shop. It is fairly gentle acid, but it can help does not damage rubber apparently.

As Duncan said , have the heater on as there is a little radiator in the cabin, that needs flushing too.

Anti freeze/coolant has rust inhibitors, pretty good stuff we can get now a day last 8 years. So if you your cooling system is clean, it stays clean. Distilled water is meant to be better to add to the concentrate, as the minerals are removed, some tap water has lime etc..

Gosh still can't get my head around aluminium radiators, copper is a far superior material imo. Aluminium is cheaper for the manufacturer, they are starting to replace some electrical wiring with aluminium due to it being cheaper. But no way in my mind is it able to outlast fatigue and bouncing around as copper. Can burn out grass seed on copper too with a gas torch, plug a leak with with lead, not aluminium.

It does not make sense water comes out the engine unless from the drain on the block. Trickling down the side?

The reason I'm flushing it is so I can put in new coolant with my new radiator. I don't know exactly what coolant was already in there and I've heard you shouldn't mix types. How true is this? Would residual coolant in the thermostat or water pump cause problems mixed with the new stuff I put in? I figure the rest of the system will be pretty clean as I managed to flush through the heater hose through to the block drain.

But in Duncan's video, the water also circulates back to the radiator and overflows. This is not happening for me. I don't get it, maybe it's the low pressures from the hose I'm using.

 

[sodafeld1]

no don't mix coolants, don't drink the kool aid.
Is your thermostat in? If so it shall be closed, it will stop flow at that point. There are two available I believe, one which opens at 82c and another which opens later for cooler climates. Even the tridon ones are ok, they have a wax inside which when heated opens the valve. They can get stuck and or fail.

Always good policy to chuck in a fresh thermostat, pretty cheap things. (after flushing)

You should get it overflowing for sure. Can stick the tap hose in every hole available for coolant. Play around, it won't hurt. I like the phrase f around and find out. There is an inlet and outlet hose for the radiator, probably the easiest access, but need to remove thermostat.

If the water comes out clean, you are pretty good. But if obsessive and like to do a proper job, addressing every hard coolant pipe is worth doing if there is any corrosion, aluminium oxidises and gets pitted, often the steel t on top of the head gets rusted at the hose join if it was neglected and the little short bypass hose which runs from the thermostat housing to the water pump housing..
Sorry, how many k's on the engine? Did you see any gunk?

Cooling is an excellent place to start when on a brand new second hand.

 

[Touz]

no don't mix coolants, don't drink the kool aid.
Is your thermostat in? If so it shall be closed, it will stop flow at that point. There are two available I believe, one which opens at 82c and another which opens later for cooler climates. Even the tridon ones are ok, they have a wax inside which when heated opens the valve. They can get stuck and or fail.

Always good policy to chuck in a fresh thermostat, pretty cheap things. (after flushing)

You should get it overflowing for sure. Can stick the tap hose in every hole available for coolant. Play around, it won't hurt. I like the phrase f around and find out. There is an inlet and outlet hose for the radiator, probably the easiest access, but need to remove thermostat.

If the water comes out clean, you are pretty good. But if obsessive and like to do a proper job, addressing every hard coolant pipe is worth doing if there is any corrosion, aluminium oxidises and gets pitted, often the steel t on top of the head gets rusted at the hose join if it was neglected and the little short bypass hose which runs from the thermostat housing to the water pump housing..
Sorry, how many k's on the engine? Did you see any gunk?

Cooling is an excellent place to start when on a brand new second hand.

thanks mate, i got the thermostat off and flushed the whole system. The hoses seem fine but a bit brown and scaly inside, esp. the intake and outlet hoses from the radiator - any recommendations on how I could clean these?

I noticed the thermostat has a whole drilled into the top. What's this about? I will buy a new one, just curious why someone would do this. Is it about air bubbles or something?

Also, before removing the thermostat I noticed it is weeping a bit of coolant where the upper and lower housing meets. The gasket was new (a month or so) but whatever my mechanic had used for sealant did not seem to really set, as it was was leaking out a bit. Any recommendations on sealant to use on thermostat gaskets?

 

[sodafeld1]

I would just get new hoses, if brand new secondhand, and own her, love her. Don't cheap out with the cool. I find water pump sealant better than hylomar blue for coolant stuff as an example.
I think I recall seeing a hole in a thermostat before, get a new one or look at it, it probably has same hole.