petcocks clogged

[tystick]

while trying to drain the engine..1990 4.3l merc...water trickled out. Is there any trick to clean these out?

 

[ziggy]

Re: petcocks clogged

tystick, mine were clogged too. i got three drains, 1 petcock and 2 drain plugs. both my plugs wouldn't even trickle. used a 3" flat piece of spring steel to ream the holes out. i had a bunch of sand in mine, after much reaming, got them to trickle then the clog loosened and came out. drained fine after the sand came out. hope yours is as easy,,,,,, jim

 

[Laddies]

Re: petcocks clogged

good answser ziggy but if you have a 4.3 you didn't get all the drains 1 each side of the block 1 on each manifold and some early units had 1 on each exhaust elbow a water cooler or remove hose from one end and the large circlation pump hose --bob

 

[tystick]

Re: petcocks clogged

not sure what you mean by water cooler or remove hose? and large circulation hose?<br /> Would the rust / sediment be primarily located at the bottom two block petcocks?

 

[deputydawg]

Re: petcocks clogged

You should be able to remove the entire petcock and clean it. The wire trick works good though.

 

[P.V.]

Re: petcocks clogged

Smart people also "back-fill" all of those areas with the "pink" anti-freeze, JUST in case!!

 

[Lou C]

Re: petcocks clogged

Water cooler is the power steering cooler on the back of the motor, there is a drain plug on it too (nearly impossible to reach) but if you disconnect the hose from the cooler to the thermo housing, and point it down in the bilge it will drain. Big hose is the hose from the front water circulation pump to the thermo housing, disconnect and point that one down too to drain. Same thing with the manifold hoses. Then backfill all hoses with no tox af--I like the better propolyne glycol stuff with corrosion inhibitors for corrosion protection over the winter hibernation.

 

[Scaaty]

Re: petcocks clogged

Poke around in the block holes to get the crud out the best ya can. Pull the stat and stick a garden hose in there and flush it out. On my 350 I also just pull the two exhaust hoses off the stat manifold and funnel in antifreeze until it runs back out. Aftermarket Barr manifolds and can't even get to one drain. I use Wally World antifreeze at 5 something a gallon. Quart in each side, and the rest on the stat opening until it comes out the block drains. Put the drain plugs back in with teflon tape. If you leave them open, it will rust and tough to get the plugs back in.