The Ford Barn

j.grif · 09-28-2015, 11:29 AM

Milky oil on dipstick on 21 stud flathead. Looks like a leaking head gasket,but how to find out which side is leaking on this dual system??

41Joe · 09-28-2015, 11:31 AM

I think that by checking your spark plugs you can see if one or two are wearing different than the others.

SofaKing · 09-28-2015, 02:00 PM

Quote:

Originally Posted by 41Joe

I think that by checking your spark plugs you can see if one or two are wearing different than the others.

x2. The plug in a cylinder that is ingesting coolant will look clean, not the soft brown or slightly sooty black. Same with the combustion chamber/ piston top, they tend to get steam cleaned. I have also had some luck using an infrared thermometer, the head had localized hot spots at the leaking cylinder. I was not working on a flathead but think it should still be true.

Karl Wolf · 09-28-2015, 06:40 PM

Check the pan rail, I have a 1937 LB block that has expansion plugs on the pan surface... they will corrode after the first seventy years or so... They may be the first thing to check.

Karl

Ken/Alabama · 09-28-2015, 06:57 PM

Remove the upper radiator hoses. Then remove the belt. Then fill the block with water till the level is up to the top of the neck. Start the engine and watch for bubbles.

j.grif · 03-06-2016, 02:54 PM

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still milky oil after replacing the four welch plug at the bottom of block. Did the bubble check as per Alabama and the right head tube had a single bubble about every 30 seconds or so. Replaced the r/h head gasket and the bubble pops up about the same. Left head no bubble. Could us info on how to pressurize the block. Thanks for all suggestions

slowforty · 03-06-2016, 10:46 PM

If you have duals you can tell which side is leaking by the smell.

Curt in AZ · 03-07-2016, 12:12 AM

Be aware that running with emulsified oil can quickly damage rod/main bearings. Once the leak is fixed and back to straight oil a reduced oil pressure will indicate damaged bearings. I've seen this with two engines, not flatheads.

Snouts out · 03-07-2016, 03:34 AM

If the heads are aluminum,it may be warped.

flatheadmurre · 03-07-2016, 04:45 AM

I think you got 2 issues here.
Leaking compression into coolant and leaking coolant into oil.
Might be that the coolant into oil leak is on the other head.
Has it overheated ?

JWL · 03-07-2016, 07:50 AM

Water in oil does not always mean the head gaskets are at fault. Cracks in valve spring area, pan rail, combustion chamber of head, valve seat area, cylinder walls and crankcase and even waterpumps(block mount) just to mention a few possible culprits. In some cases it is difficult to locate a crack without doing a complete disassembly.

El Rat · 03-08-2016, 07:58 PM

As above the culprit will show up on the plugs! There will be no doubt on the cylinders with water.

JWL · 03-09-2016, 06:53 AM

No, a leak from the valve spring area or pan rail or waterpump WILL NOT be demonstrated on a sparkplug.

keith oh · 03-09-2016, 03:28 PM

Barr's pellet stop leak will stop many very small leaks that just do not need to be fixed the hard expensive way. It was common for the old time dealers to routinely put a small can in their cars before delivery to customers. It sure cut down on come backs.

09-28-2015, 11:29 AM	#1
j.grif Junior Member Join Date: Feb 2015 Posts: 10	leaking head gasket Milky oil on dipstick on 21 stud flathead. Looks like a leaking head gasket,but how to find out which side is leaking on this dual system??

09-28-2015, 11:31 AM	#2
41Joe Senior Member Join Date: Jul 2015 Location: Huntington Beach, CA Posts: 284	Re: leaking head gasket I think that by checking your spark plugs you can see if one or two are wearing different than the others.

09-28-2015, 06:40 PM	#4
Karl Wolf Senior Member Join Date: May 2010 Location: Mill Valley,Ca. Posts: 1,509	Re: leaking head gasket Check the pan rail, I have a 1937 LB block that has expansion plugs on the pan surface... they will corrode after the first seventy years or so... They may be the first thing to check. Karl

09-28-2015, 06:57 PM	#5
Ken/Alabama Senior Member Join Date: May 2010 Location: Alabama Posts: 3,272	Re: leaking head gasket Remove the upper radiator hoses. Then remove the belt. Then fill the block with water till the level is up to the top of the neck. Start the engine and watch for bubbles.

03-06-2016, 02:54 PM	#6
j.grif Junior Member Join Date: Feb 2015 Posts: 10	Re: leaking head gasket Sponsored Links (Register now to hide all advertisements) still milky oil after replacing the four welch plug at the bottom of block. Did the bubble check as per Alabama and the right head tube had a single bubble about every 30 seconds or so. Replaced the r/h head gasket and the bubble pops up about the same. Left head no bubble. Could us info on how to pressurize the block. Thanks for all suggestions

03-06-2016, 10:46 PM	#7
slowforty Senior Member Join Date: May 2010 Location: Tinley Park Ill Posts: 1,067	Re: leaking head gasket If you have duals you can tell which side is leaking by the smell.

03-07-2016, 12:12 AM	#8
Curt in AZ Senior Member Join Date: Sep 2015 Location: Clarkdale, AZ Posts: 121	Re: leaking head gasket Be aware that running with emulsified oil can quickly damage rod/main bearings. Once the leak is fixed and back to straight oil a reduced oil pressure will indicate damaged bearings. I've seen this with two engines, not flatheads.

03-07-2016, 03:34 AM	#9
Snouts out Senior Member Join Date: Dec 2013 Location: Covedale,oh Posts: 226	Re: leaking head gasket If the heads are aluminum,it may be warped.

03-07-2016, 04:45 AM	#10
flatheadmurre Senior Member Join Date: Apr 2015 Location: Sweden Posts: 3,045	Re: leaking head gasket I think you got 2 issues here. Leaking compression into coolant and leaking coolant into oil. Might be that the coolant into oil leak is on the other head. Has it overheated ?

03-07-2016, 07:50 AM	#11
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: leaking head gasket Water in oil does not always mean the head gaskets are at fault. Cracks in valve spring area, pan rail, combustion chamber of head, valve seat area, cylinder walls and crankcase and even waterpumps(block mount) just to mention a few possible culprits. In some cases it is difficult to locate a crack without doing a complete disassembly.

03-08-2016, 07:58 PM	#12
El Rat Senior Member Join Date: Nov 2010 Posts: 260	Re: leaking head gasket As above the culprit will show up on the plugs! There will be no doubt on the cylinders with water.

03-09-2016, 06:53 AM	#13
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: leaking head gasket No, a leak from the valve spring area or pan rail or waterpump WILL NOT be demonstrated on a sparkplug.

03-09-2016, 03:28 PM	#14
keith oh Senior Member Join Date: May 2010 Location: Millersport, central ohio Posts: 668	Re: leaking head gasket Barr's pellet stop leak will stop many very small leaks that just do not need to be fixed the hard expensive way. It was common for the old time dealers to routinely put a small can in their cars before delivery to customers. It sure cut down on come backs.