flushing the cooling system

i dont remove it,you can if you want

on my sb,I remove the 2 lower t-cover bolts,1 each side,to drain the block,put them back in and flush it

you can run the engine with a rad flush,then drain and back flush it

I drill the 1/8" hole in the stat to burb it on fill up

I flush it till it runs clean with the petcock open on rad,stop water flow,let drain,flush,drain..ect

i do this 3-4 times

last time it drains,I close petcock,add 1 1/2 gallons antifreeze,fill thru the tee till it at top of rad,the hole I drill in stat lets all the air burb on fill up

test run till up to temp shut down and let cool,check water lever to make sure its full...done

thats the way I duz it anyway

never had a problem this way

if the stat is not drilled,I run till up to temp and wait for the stat to open then fill the rest of the way from top of rad...not the tee

i turn the hose on about 1/2 way when flushing thru the tee

Take the return line off at the manifold and w your rubber tipped air nozzle blow the coolant in that foot or 2 of heater hose in reverse thru the heater core. Use your hand to modulate the psi as water faucet psi is ~60 psi (at least in Nebraska) and heater core/rad are designed for ~15-20 max. If you think the rad is partially plugged best would be to take it off and back flush it the same or take it to a rad shop & let them boil it or even "rod it out" if it's really plugged w scale as chemical flushes are not stout enough to attack scale w much effectiveness. Rodding out can be dangerous to tubes that are old and your rad shop can further advise you. Back flushing is way less effective on the block/intake cause the passages are so much larger/unrestricted but if enough debris builds up in the bottom of the block cyl cyl cooling (hot spots that produce steam) will be affected but this requires core plug removal but is worth the effort. Dont know how far you want to go on your deal but throwing stuff out there

Pull the plugs in the block also.You will be suprised how much crud is there.Most times they wont drain because crud is over the holes.Rocky

My 71 Challenger was from California,and apparently hadn't had much antifreeze over it's life. The block was so full of crud I had to pull the motor, knock out all the freeze plugs and flush the block with a high pressure steam cleaner. Then that turned into a new cam,LD4B intake,headers, new exhaust,bang screech 727,8 3/4 in place of the 7 1/4,etc,etc!

I don't have a scanner, but the 1970 Field Service Manual describes a procedure using low pressure compressed air much like Rapid Robert recommends. If you can get the original freeze plugs out, it is a safe bet they needed to be replaced with fresh ones anyway.

The process to remove an replace them all on a big block car without the engine out is not for the faint of heart. Digging around inside the block through the freeze plug holes with a hooked wire can help coax some of the inner cast passages to give up their cargo of corroded gunk.

Kelley-Moore Paints sells a product called Corro-check. It's used to stop corrosion in water-based spray equiptment, and it does! It's blue in color, cheap, is dilutable(a little goes a long way), is unhindered by heat and is an extemely long-lasting corrosion inhibitor. I use it with distilled water alone or together with anti-freeze.

Back in the day we drained the system, refilled with clean water and added 5 or 6 tablespoons of crystal drano, Ran it for 10 or 15 minutes then drained again. You would be amazed at what came out.

Russ

i'll probably start with the tee method in the line. i know i don't want to go for pulling the freeze plugs and all, i think i would just pull the engine and do some other stuff at that point as well.

thanks for all the responses.