The Coolant Leak That Is Fighting Me

[keithb7]

My 1938 Chrysler. It seems this area was overlooked when the 25"  251 engine was last rebuilt. It has been leaking. Now i can see why.

We milled the water neck today. Took 0.025" off it. We cut a new thermostat groove. Now I will deal with the cylinder head surface. The left brain lobe is saying don't take the head off at this point. I am thinking JB weld and block sand it. Yet I will admit, my right lobe is interested in taking the head off. Yet the left side knows I'll open another whole can of worms.

 

Not at this time. Not right before cruising season!

 

 

 

 

Edited March 27, 2022 by keithb7

[John Fleming]

Was the water leak between the water neck and the cylinder head ?

[RobertKB]

Looks like you did what needed doing and it should stop the leak. Nice job.
 

Regarding the head two sayings come to mind. “If it ain’t broke, don’t fix it” and “Let sleeping dogs lie”. I see no point in pulling the head unless necessary. “Just to have a look” is not necessary. 

[keithb7]

Yes, the leak was between water neck and cylinder head. I will try JB weld at the head surface area. Then block sand it.

[Plymouthy Adams]

if this has you messed up...hope you are not planning on buying a shortbread cookie with chocolate and caramel

[keithb7]

Naw. I’m not messed up or confused. I figured some members here could maybe learn a little from my example. I open my myself up to criticism I suppose. Yet its worth it to help others. 

[DJ194950]

Your idea for the JB weld repair  worked well for me and it is still working  6+ years.

 

DJ

Edited March 28, 2022 by DJ194950

[Plymouthy Adams]

I was making a reference to left Twix verse right Twix....either is the same

[Sniper]

I usually run a draw file over those areas if it's not too bad.  That will clean it up and flatten it. 

 

Lost a nice running 413 due to a leak in the same area and me just glopping on enough RTV to seal it.  Problem was I glopped on enough so that when I bolted it together a nice big chunk squished out on the inside, either holding the thermostat closed, or closed enough to case the engine to over heat and blow out a freeze plug, by the time I could get to a safe spot off the highway the engine was done.  Melted a piston.

[harmony]

One of my B&B carb body and lid both looked like your cylinder head.  Plus there are only 4 machine screws holding the carb together so it was always seeping gas.  I did the JB weld thing and to get the body and lid both flat,  I taped a piece of 320 grit sand paper to a piece of window pane glass and rubbed the body and the lid back and forth and round and round on it, after filing off the high spots with a bastard file.  

That did the trick.

I find that the "original" JB weld is better than any of the specialty JB welds out there.

[Dodgeb4ya]

I am having the same leak on a 413 six I just finished rebuilding last year... not a bad leak but after a week a small amount of coolant weeping next to the housing and head..

Corrosion/erosion of the thermostat housing... the thermostat housing gasket had to try to seal a thin area on the housing. Could not get it to stop weeping.

Finally found a nice thermostat housing that was not eroded....end of leak.

Edited March 28, 2022 by Dodgeb4ya

[Bryan]

12 hours ago, keithb7 said:

Naw. I’m not messed up or confused. I figured some members here could maybe learn a little from my example. I open my myself up to criticism I suppose. Yet its worth it to help others. 

And thanks very much on that. I have a MS WORD file on salient points you and others have mentioned during videos. Also any problems that you and others note, I put it on a list to remember.   Just like the oil galley leak in the rear,  I'll definitely do the plug myself and add an core plug on top.  And like Dodgeb4ya's comment on double brass core plugs in the rear, I'll buy them extra and use them.  I really helps to hear issues and fixes.   Thanks again.

[DonaldSmith]

I was getting mysterious puddles of coolant in the spark plug wells, mostly at No. 1 and 2, after the car sat idle for long.  Apparently, running the car would help boil off the coolant, and the plug wells would be dry.  After the Winter down-time, coolant re-appeared in the two front wells. 

 

I sopped up the coolant with paper towels, and found that the source was at the head of the nearer bolt.  I could have drained some coolant, removed the bolt, and Permatexed the threads and under the head.  But no.  I had to remove the t-housing and related paraphernalia.  I cut a new gasket and reinstalled the housing, with gasket surfaces and bolt threads slathered with the non-hardening sealant.  Always having to do things the hard way, but not as hard as milling surfaces. 

 

These are non-pressurized cooling systems, so I'm putting my faith in a squeeze-tube fix.