On Mon, 28 Dec 2015 06:10:14 -0800, Jon Danniken
wrote:

On 12/27/2015 04:34 PM, My 2 Cents wrote:
On 12/27/2015 12:54 PM, Snuffy "Hub Cap" McKinney wrote:

I did the garden hose thing on a old Mercruy Comet I once had, I let
the water run through the core and into a 5 gallon bucket just to see
what and how much came out. A lot of rust, actually a whole lot of
rust. I suppose that heater core was the low part of the cooling system.
I hooked the hoses back up and the heater worked liked new after that.
Prestone makes a kit you can cut the hoses and do the same thing which
might or not be a good thing. This one is on ebay but the auto parts
stores have them.

http://www.ebay.com/itm/Prestone-Ant...-/221978480521

The problem with those kits is that the cap on the fill fitting can
weaken or come loose and end up leaking. It's also not recommended to
flush the entire system from the heater hose; while heater core flushing
is done during a routine flush, it is done seperately from the engine
block and radiator.

Personally, I back-flush the block from the thermostat housing (with the
hose still on), and the radiator from the bottom hose. I just use a
hose gun and pulse the input so I'm not subjecting the system to the
full pressure of a typical residential water system.

Jon
The flushing machine does basically the same thing, with regulated
pressure being pulsed through the system. Been a long time since I
last used one so I forget all the details - and yes, sometimes the
caps/"T"s deteriorated with age, but usually only on the cheap "clone"
parts. If flushed every 2 years, as was recommended back in the day,
any mechanic worthy of the name would catch a deteriorarting "T" and
replace it before it caused a problem. Most were good for about 10
years minimum.