Flushing Cooling System

[52dodge]

I have been reading about how these old flathead 6 are prone to hot spots from rust and debris in the cooling system so i was wondering if there would be any issues with flushing it with one of those prestone cooling system flush kits that you add the cleaner to the system and hook you're garden hose to it?

[_shel_ny]

I have been reading about how these old flathead 6 are prone to hot spots from rust and debris in the cooling system so i was wondering if there would be any issues with flushing it with one of those prestone cooling system flush kits that you add the cleaner to the system and hook you're garden hose to it?

You would be better served to pull the welch plugs (freeze plugs), pull the water pump and distribution tube, and flush and flush, and flush with a garden hose. There is stuff in the water jacket that will never come out with cooling system flush.

 

Just my opinion, and worth little.

 

One thing to try first, is to open the petcock drain on the side of the block and see if anything comes out.

[Daliant.]

Those "kits" usually aren't as effective as a good ol' fashion manual flush job.

[doctor dirt]

I just did a basic flush opening the side petcock on the block and flushing the radiator and getting a DV 3 thermostat with some good old fashion green Prestone!! The car came off being spiked at 212 and moved down to 185-90!!! Ruffed up the thermostat housing and took a peek at the water pump too. Everything was good except for a beat up thermostat and a brutal looking radiator cap. You need a 4lb. cap on that system. Doc

[52dodge]

ok someone musta replaced mine at some point cause it has a stant 16lb lever style

[chopt50wgn]

Opening the drain plugs on the block is a good way to drain the system. Sometimes when you open the petcock or remove a plug the hole can and sometimes be covered up with a rust layer. A screwdriver will break the rust and allow for drainage.

Using the Prestone system is a backflush and really only does the heater core and radiator.

[Phil Martin]

I unhooked both radiator hoses, stuck garden hose in top inlet on motor. Stuck air hose in and packed a rag around it. with the pressure it flushed motor out real good. hasn't got hot since. Had a new radiator so just flushed motor. Also put a 6 blade fan on it.

[doctor dirt]

52 dodge; the 16lb isn't a good match for these opened systems. Make sure your radiator is stock before you switch caps, Stant made a release pressure first 4 pounder or the older stock ones are easily found. Theres different opinions on the thermostat but I'm thinking the DV 3 160 is the one for the car here in S.W. Florida. I'm just below the tropic line and in the summer months we "live on the Sun" down here!!! Doc