flushing coolant on a 4.6 - engine drain plugs?

[0xowner]

I'd like to hear some opinions....

I am refreshing / flushing the coolant (gold VC-7-B) on my 2002 expedition 4.6 L as it appeared discolored (rusty tint). It probably had gold in it but diffidently it looked orange !

One of the previous owners had flushing T's in both front heater hoses both closer to the heater core and under the windshield area. I don't like them as they are right above those coils on Bank 1. The heater hoses have the T's also for the rear heater runs but it seems those T's are quite smaller in diameter and neither line is getting hot (supply is not channeling into them).

In looking at the fluid sampled from original radiator drain and the 2nd, there is some slight sediment. Pulling the petcock out, some flakes of rust were present.

Both refills have been with distilled water (88 cents per gallon + tax at Wal Mart). I have only been able to get or 10 quarts per drain but making progress.

the vehicle is 14 years old, owner last 3 years may have allowed it to sit for months at times (believe a foreigner with vacation home here). Some one appears to have not ignored maintenance as the flushing T's are there. When I look for a coolant drain plug on the engine itself, there appears to be a newer bolt on driver's side right below the last, bottom freeze plug nearest to transmission. It appears to be brass.

I've been running the heater (front and rear) between the drains and the rear is not getting the heated water.

Heres a few points I like to hear back on:
- is that the drivers side drain plug? and if removing it, should i replace it or reuse? should there be lock tight or anything used on it? replace a gasket there?
- thoughts on the rear heat? should I remove the heater hoses in front to possibly clear out anything in the rear hose T's ? Would you use the heater hose flushing t's ?
- any use in removing the rear heater core and flushing it? installing flushing T's back there?
- would it be good to use motorcraft coolant flush in between drains?
- any other tips or thoughts?

Thanks in Advance.

 

[0xowner]

well, i began to dig into the rear lines and heater core.... appears it may be blocked up.

When the supply line expelled the coolant, it was very dark, darker than the coolant from my original radiator drain. The water later being supplied now was clearer and the line is now hot vs before of never heating up. Seems the coolant there was trapped somehow.... because the flow is going now, it must not be the front supply T.... hence going after a blockage in the rear heater core.

I am heading out now to pick up some 5/8 heater hose line and perhaps a few t's. I want to try to flush it while in place before disassembly of the vent box. I already have the panels off.

 

[0xowner]

I wrapped this up last week and here is my photo album:
http://www.expeditionforum.com/members/52862-albums1029.html

i did attempt to consolidate all the heavy contaminants, rust flakes, etc.

I never opened the engine drain plugs.
I flushed both cores and extensively flushed the rear heater supply and return hoses. Most of the heavy, choclate water / sediment came from there. Nearly 1 quart.

 

[ExplorerTom]

I didn't see this until now.

I pulled my driver side block drain this past January. I got some crud out of there. I didn't pull the passenger side because it's behind the starter.

I reused the plug. If I remember right, it's just a plug similar to what's on the transfer case. I didn't use loctite or any kind of thread sealant. No leaks.

Here's my results:
http://www.expeditionforum.com/234974-post110.html

 

[0xowner]

good post Tom and pics.

I must say that in flushing this, I think that including the rear lines from the rear core are a must. I have no idea how mine got that blocked up in the line. the front heather lines had t's so I know that the previous owner / shops had addressed a decent flush... I tend to think that they missed the rear being so bad though and the blocked lines were missed.

The rear lines can have T's installed much more easily than the front. I got a lot more debris out than you, time will tell on mine.