Following the engine rebuilt, we been putting her all back together and making good progress. Last thing we did yesterday was put in some engine oil to test the pump...(worked perfect), with the head on and all holes plugged, we added enough water to the block to make sure nothing was leaking.

So pulled the drain plug this morning and first thing to come out was about 1 cup water. That was disappointing.

So we pulled the head back off and found a wet head gasket, that delaminated when we pulled it off. Best guess is coolant was wicking past gasket and on into the block. But we have also filled block back up to top to see if any coolant is getting past O rings of the sleeves.

Head gasket came with rebuild kit from Reliance. Rumor has it (now.....after the fact) those are suspect. So looking for a Fel-Pro replacement.

Main question, however is the head bolts, which come in two sizes. One group is 3/8".....4 bolts on right side are larger. My service manual shows torque for all head bolts to be the same.

Have been told that on the WD45 and maybe D17, same thing exists....head bolts are two different sizes but torque for those goes up. Is greater for the larger bolts.

What is the best plan for the D15? Leave them all the same or increase torque for the larger ones?

You made steel O rings?

Not sure what that means. The head gasket shown included metal fire rings around each cylinder, which I hear is far better than one without.

The copper color is the permatex spray on sealant sold for head gaskets.

Just looking at the gasket, pathway coolant may have taken was lower left in photo.....from coolant channel to one or both of the slots used for the push rods. Just wicked through.....which is where it was wet and where it delaminated when head was pulled off. Where metal core of the gasket is showing.

Still looking for thoughts on the head bolt torque.

Am wondering if a person could secure a mill sheet of copper of the appropriate thickness and mill there own gasket then use copper sealer as a work around?

Orangeman

If I recall the book has the big bolts and the little bolts torqued to 85 ft lbs???  Which I thought was pretty light but I followed the book regardless.  I did however take them up after the fact trying to get rid of the leak.  Not sure how far I torqued.  But it did not stop the leak.

In the D15 service manual, the Series II (160 engine) has all bolts torqued to 85 ft. lbs. But the service manual for the 160 engine is pretty brief compared to the info for the series 1. It could be right, or could be an oversight.

I hear from some better informed guys than me that a couple other AC engines like the D17 and maybe the WD 45 do use more torque for the larger bolts. Not sure what they are, but more. The large bolt side appears to be where the leak occurred.

So more torque might be right, or it could be all the same. Trying to find somebody who knows.

Ive had same head gasket problems on a D17. You can identify the bad head gaskets by the following: the width of the steel fire rings on the BAD gaskets are the same width on both sides of the gasket.

The good head gaskets have a wide width fire ring on the block face, and a narrow width fire ring on the CYLINDER HEAD side. These bad aftermarket head gaskets started to hit the market last December from what i can tell. They do not compress enough under torque to seal. This, in combination with too much sleeve standout from aftermarket sleeves causes coolant leakage! Anywhere you see copper still showing on the gasket means it did not seal under torque on those areas!

The head bolts should be 2 different torques for different sizes I believe although the factory manual says 80-85 for the 7/16 bolts, doesn't mention the 1/2" bolts. The original D15 head gasket didn't have fire rings, but most use the D14 gasket with fire rings.

As near as I can recall, the fire rings on this gasket were the same. I wasn't looking for different sized fire rings, but was looking for any other differences to find a top or bottom. As I recall, both sides looked to be the same.

Will look at the flange on the sleeves to see if they bed flush or remain a bit proud. I remember having concern about those, and fire ring on top of them and if it would allow you to compress the gasket enough to seal it. Assumption was it was made that way so it must?

We followed the book as far as torque amount and pattern, except we did it in steps. Started inside to 40 pounds, then worked our way out. Then started at # 1 again...this time to 85 pounds and worked our way out. Then when back and tested them all a 3rd time.

Back to fire ring......wide side to block side vs cylinder side? Aren't those the same side?

So does wide side of the right fire ring go to the block or head?

 

 The gasket should have "This Side up" embossed on it.  It really isn't possible to get it on wrong as there is a long and a short distance from the bore to the edge of the block front and back. 

As I study the bolt pattern again, PaulB is correct. Only one way to put the gasket on.

As for the bolts, 4 are shorter, but are also larger. This is the 160 engine.

The good head gaskets have a wide width fire ring on the block face, and a narrow width fire ring on the CYLINDER HEAD side.

So imagine our frustration when we uncork one that does have a mix of bolts. And even the parts book is no help......they only mention various numbers.....some lengths, no sizes.

But since this engine does have a mix of bolts, we are leaning towards borrowing the concept of giving the larger bolts more torque, same as is done on other AC engines where there is a mix of bolts. The question will be how much.

Another thing that is a puzzle.....how we found it and as shown in the parts book. ONE....and only one....head bolt / cap screw has a washer under it. Why is that?

If memory serves, all the head bolts go into blind holes. Two of the manifold studs go into water.......and I would love to know why. (Those are sealed with teflon tape).

And if memory serves, the two manifold studs that go into the water jacket broke off and had to be drilled out to extract the remnants. Again, would love to have a sit down with the engineer that came up with that one.

Lot of curious things about this engine and tractor I would love to have explained to me by the guys who designed it.

Replacement head gasket ordered through a local supplier. Gent who is about 80 dropped off a new Fel-Pro gasket. He happened to be the same guy who was trusted to turn down the crankshaft, and is well respected by locals when it comes to engine rebuilds. He is the man.

However, before that showed up, as luck would have it, a pair of alternative head gaskets showed up in shop where wrenching is taking place. Should probably mention that the building is about 45 years old and has been used almost exclusively as an AC repair shop. On any given day, there are from 6 to 8 AC tractors in there in various stages of undress. Currently holding a C, pair of 185's, pair of 190XT's a WD and a 7010.....plus a D15. While sorting through one of several piles of various surplus gaskets, two different Victor head gaskets showed up. No clue as to their origin or history, but there they were.

One is what is believed to be similar to what she was wearing when she left West Allis.....thin and no fire ring. Alternative was a thicker Victor with ring.

When gent who brought new replacement in saw the Victors, his mood improved. Said at one time they were A#1 first choice if you wanted the best. Would be using those if it was his......and no sealant. Says so right on the gasket. He confirmed that was right.

So thicker gasket with fire ring went in, no sealant, smaller bolts torqued to 80 ft pounds, larger bolts to 90 ft pounds and that did it. Held head water for about 5 days with no leaks, so buttoned her up and she is now back together and running.

Pile of gaskets were replacements were found. Lucky to have access to such parts.....

And for future reference.......part number for the gasket used was Victor 3145. Those can be found on ebay and a few other places. Now sold under the name of Victor Reinz. Not sure if quality of those is still the same as the one we used.

Have heard from a few sources that the head gasket included with the Reliance rebuild kit is suspect. If that one is used, I might suggest putting some water in the block and head after torquing it down to test it overnight before going much further.

Also confusing as to what to do about using sealant on the gasket. D15 service manual says use it. The Victor gasket had the words "Use no sealant" printed right on it. The D17 has head bolts of two sizes and service manual for that says to torque larger bolts about 15 pounds more. D15 manual for 160 gas is silent on torque for different sized bolts. Only gives one torque (80 to 85 foot pounds) for all. Again, hard to know which is right. Pretty much forced to pick one and go with it and hope it works out.

Someone more versed in the D17's would have to chime in. With 4 different series, I suspect there were lots of changes.

D15 only has two...Series I with smaller engine and serial #9001 and up, which were series II with 160 engine. Seems to be different opinions if all 160's had different bolts or if all were the same. This thread alone has had guys report both.

What I do know is my service manual has pretty extensive data on the D15 Series I, but does not cover the 160 Series II engine in the same detail. In many places applicable to 160 engine, service manual is pretty brief. Hard to know if that was intended, an oversight or they just got tired of writing.

Orangeman