The Stovebolt Site Forums The Shop Area Engine Shop Perferred water coolant cleaner, 235 engine.

I know this here topic has been discussed a time or too, but just can't seem to find it? With my petcock open in the lower aft part of the block, I am still trying to get the coolant to drain out. I had run some local Autozone, O'reily's coolant cleaner and still no coolant coming out of the petcock. Way back when I was having a leak in the radiater so I think possibly I put a little to much Bars leak in it preventing the block to drain. Now, I have the radiator, water pump, thermostat and water temp. fitting out trying to back flush, front flush etc. etc. still no water coming out of the lower fitting. The engine still runs really good and once warmed up for say about 10 minutes or so it will only show about 80 degrees on the water temp. gauge. I am now thinking about removing the 2 freeze plugs? Need a bail out here Bolters, Thanks..

Unscrew the petcock and put a drill bit in a tap holder and start twisting….you’ve got a buildup back there. Not uncommon at all- even after having your block “professionally” cleaned.

Question- were you ever able to get water out of the peacock? Might be old scale buildup, and not Bar’s.

I used Bars once in my life- it glued the heater valve shut in my car. After that, I never used it again.

Are you talking about the gauge on the dash showing 80 degrees? Do you mean 180 degrees?

Don't trust dash gauges unless verified by other means like an infrared thermometer or a second gauge temporarily plumbed in.

Not quite sure if it ever drained coolant once it was hot tanked. I double checked the water temp. with another gauge and it showed 85 degrees. I believe the water jackets through out the engine are clogged preventing the engine from coming up to normal operating temp. I don't want to run the engine in this mode if it would hurt it. Like I said earlier it runs really good as we speak. Thank you..

I've used a piece of steel cable in a drill motor to clear the crud out of a petcock drain port, but that's only the beginning. Once the coolant will drain, you'll need to circulate a very aggressive cleaner like phosphoric acid or Trisodium Phosphate (one at a time, not together) to clean the crud out of the bottom of the block. The acid dissolves rust and other metallic contaminants. The TSP cuts greasy deposits. Both chemicals are available on Ebay and they can be mixed in much stronger concentrations than are available in commercial flush products. It will be a long, tedious process to get the block really clean.
Jerry

On my 216 the water used to only drip out of the petcock. Even after I removed the petcock and jiggled with both a wire and nylon brush it would only run very slowly. On this site I read about using Evaporust. I filled the block with Evaporust and let it sit for 2-3 days, it dribbled out, not much better...I used the wire in the petcock hole again and also used a shop vac nozzel on the petcock hole. The 2nd time I did the same and then the Evaporust ran a bit more freely...but not my much. The 3rd time doing the same steps, the shop vac did the trick and the Evaporust gushed out. It just took a lot of time for the product to work.

I took and old 3/16" welding rod and wiggled around in the peacock hole for a while and it feels like I am just scratching bare hard surface? I don't want to use a drill in a drill motor for something mighty stupid will happen. How far in can you go before you touch the other side of the block? I don't know why my phone will not let me spell some of my words correctly? Like petcock.

Phones don't like words like petcock. They also don't like cock-a-doodle-doo. The last time I had this problem with a 235 I first removed the petcock and pushed a coat hanger wire up and through until I got a small dribble. You will need to bend it to make it go through...going straight in will not work. This will be encouraging to you but you can only go so far with this scheme. Next I replaced the petcock and removed the water pump and poured CLR undiluted into the block until it reached the highest point it could go without running over. Then I left that for a day. CLR loses its strength as it does its work. By now you can appreciate the reason for using the coat hanger to open up the area a bit...I needed a way to let the CLR out. Then I drained the stuff out and repeated this again, leaving it to sit another day. Then with all that drained out I poured CLR in there to about 1 inch from the top of the water pump opening, got my coat hanger and worked it back to the very rear cylinder (through the water pump opening). I put a bend in it and twisted, poked and prodded until I was able to dislodge as much of the junk as possible, removed the petcock and let this all drain out. Then I repeated that last procedure a couple of times until I got things as free-flowing as possible. Then just because I had about 1/2 bottle of CLR left I poured it in and left it overnight. It took care of as much of the problem as I needed. Good luck!

Last fall, I bought the ingredients to do BOTH (not at the same time) the muriatic acid and TSP flushes on my truck. Gotta find time to actually do it.

Some years ago, I did a pretty elaborate “IV” circulation flush when I first got the truck. Ran a strong vinegar solution with a pool pump. Into the block drain, out the water neck, and back into the same container that the pump sat in. My radiator was already junk and I wanted to get the engine as clean as possible so I didn’t plug up the new radiator.

Edit: must give HRL credit for introducing me to the concept.

I use muriatic acid to remove rust from cast iron pans all the time.Pint to 5 gallons. Pour the acid into the water, not water into the acid... works good. Let it sit for a while . When it smokes you know it's working. Then use trisodium phosphate or some other cleaner and flush accordingly.
Beware..
Muriatic acid eats aluminum for dessert!

Well I want to thank my fellow Bolters for all your help I now have water running out of my rear peacock, been flushing etc. etc. I want to replace the thermostat, I am running a 180 and of my local parts guys told me I should be running a 160, so what do you guys think here?

When open, my 235 runs between 180 and 185, even on hot summer days. I want it to open at its operating temperature regardless of ambient temps. A 180 brings it right up to operating temperature, so I use a 180.

Both 160 and 180 are listed in the shop manual (page 6-88) as being acceptable for use with permanent anti-freeze:

A 160 will begin to open at 157-165 and fully open at 185.

A 180 will begin to open at 175-184 and be fully open at 204.

I've never had mine off so I don't know if its stamped 160 or 180. The engine runs at 180-185 year round. A 180 T-stat will never fully open if your engine typically operates at 180 degrees, however.

I'd take a look at your old T-stat and see what temp is stamped on it and install the same one.

My 59 235 runs a 180° thermostat and runs at or really close to 180° when hot, regardless of the outside temperature, so my recommendation is 180°.

By the way, I run a 4 lb. cap on the radiator.

If you want to have any heat in the wintertime, run a 180. If you choose to run a 160, buy a good set of Carhartt coveralls. The engine won't care either way. Just be sure the radiator is in good shape and clean before installing the hotter stat.
Jerry

My 235 in a 51 truck has a 180 stat. It runs pretty much 180 on the nose all the time EXCEPT…..

When idling for an extended period (very long stoplight) on a very hot day. It will begin to creep up. Drops back to 180 super fast once the truck is moving again.

I have the short shaft pump which places the fan in a less-than-ideal location. Some day, when I have things torn apart, I will move it up where it belongs via Dave’s adapter plate. It hasn’t been a big enough issue to be a problem.

OL'55,
I lived in Palmdale for several years with my 1950 3100 truck with a 1957 235. You have extremely HOT summers and cold winters. I found the 180 degree worked best. Those 115 degree days the temperature would run 190 when I was ON the gas (3 speed original 4:11 gears). Winter I had Nice warm heat out of my 6 volt Arvin heater. Good luck.
Todd