The Stovebolt Site Forums The Shop Area Engine Shop 235 Engine coolant flush PETCOCK

Where might this thing be? After reading the archives here on coolant flushing and proper thermostats, etc. I saw a post mentioning a block flush petcock on the driver side, low, near rear of block. I dont see one anywhere, on either of my two engines. Is it hidden behind the bellhousing perhaps? TIA

It's on the drivers side about 4-6" in front of the bell housing about 5-6" above the pan. It's 3/8" pipe thread. The petcock might have been repalced with a plug. I'm going off of memory here, but that should get you close. It's there!

Nope, no plugs, no petcock. There are the two bosses that the bellcrank linkage bolts too. It wouldnt be disguised as one of those, would it? Engine is a '61.

I just measured and the plug is 1 1/2" from rear of block and 4 1/4" up from pan gasket.

[img]http://home.nycap.rr.com/lederman/images/blockoil.jpg[/img]

Thanks guys, I figured it out, the return spring for the throttle is attached to a bolt that is stuck in that hole on mine. I got it out, and spent the better part of the last four hours trying to get the thing cleaned out and flowing freely. No luck. Dug lots of gunk out of there, then attacked it with degreaser, got more stuff out of there, flushed it with brake cleaner, more junk came out, went at it with a pump sprayer of muriatic acid, its running clean out of there. But nothing will drain down from the upper part of the block either. As the head and water pump are removed, I can tell there is no water being forced up thru the block opening either. Any suggestions?

I'm not sure What is happening with your block. I adapted a pipe nipple to a garden hose connection on mine and back flushed the block that way.

Get a coat hanger take out the petcock and start digging and flushing. What happens to these engines over time with neglect is crap builds up around the rear cyl and they tend to over heat with no coolant flowing around the cyl. You must open it up. Good luck. You may have to take off the water pump to get more stuff out. Time spent cleaning will pay dividends.

Is a 1954 vintage 235 engine the same?

The head and water pump have already been removed, and I was able to flush lots of rust out of the block that way. Used pipe cleaners, coat hangers, degreasers, acid, etc. but cant get the bottom hole in back of block to open up. Wasnt having any overheat problems before, but have engine all opened up for new cam and lifters, and freshed head and will be putting newly re cored (3 row) radiator back in. Trying to do all the preventative maintenance I can before buttoning everything back up. I'll play with it some more this afternoon.

Dave,
Yes. All the 216's and 235's have a tendency to build up junk around #6 cyl.

Try weedeater string.

Did you try back-flushing, like Dave S. said? Go to the hardware store, get a 1/4" pipe nipple and an adapter to a garden hose. When back-flushing I like to rig so that I have a valve close to the truck so I can see what's happening.

You could also hook up to an air compressor, if you have one. The threaded end of an air hose is 1/4" pipe thread, too.

Well, SUCCESS! I had tried all of the above except the air compressor idea. A good idea. Two days ago I had just finished routing the lock out cable for the old Borg Warner OD tranny. I had a little extra push/pull cable left, of the lawn mower throttle cable variety. I used that as a small diameter "snake". Was still a little work, but was sturdy enough to twist it's way thru the gunk. All is running nice and clear now. Thanks for the help. Now I gotta go out and clean the river of rust off the driveway.

Pull the freeze plugs & flush it.