What could be causing this? - MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information

TractorBob · 12-14-2010, 12:07 AM

I just replaced the head gasket on my suburban about 2 weeks ago and it was running great. While I had the head off, I cleaned the carbon build up off the head and top of the piston and checked everything which looked to be good and healthy. There was no scoring in the cylinder and the valves seemed tight, without taking the valve spring inspection cover off.

Today I noticed that it was leaking in the same spot again, just above the carb. I was degreasing the motor and sprayed some soap and thats when I noticed it was bubbling out. I tightened the head bolts down and it was still bubbling. I am going to pull the head off again tomorrow and check it again. Hopefully there are not any cracks anywhere.

GT_80 · 12-14-2010, 12:10 AM

If there is, I have a 1967 SS12 HH120 motor I will sell you for a great price!!!

JVHBRONCO · 12-14-2010, 05:56 AM

did you check the head and block with a straight edge? may need to resurface one or the other or both....most of the time it is just the head needs resurfaced.not hard to do.

Kbeitz · 12-14-2010, 06:31 AM

Glue a sheet of sandpaper to a sheet of glass...
Rub head on paper...
Any low or high spots will show it's self ...

TractorBob · 12-14-2010, 04:39 PM

I am going to try the sandpaper idea now. I'll let you know how I made out. Thanks Bob

TractorBob · 12-14-2010, 08:40 PM

Sandpaper worked on the head. It was all twisted and warped. I put the head back on sprayed some soap around the head gasket and cranked it over and it is still bubbling.

How do I resurface the cast iron block? I pulled the motor and am going to start cleaning all the built up oil and dirt off it. I am even thinking of repainting it.

GT_80 · 12-14-2010, 08:54 PM

Quote:

Originally Posted by TractorBob

Sandpaper worked on the head. It was all twisted and warped. I put the head back on sprayed some soap around the head gasket and cranked it over and it is still bubbling.

How do I resurface the cast iron block? I pulled the motor and am going to start cleaning all the built up oil and dirt off it. I am even thinking of repainting it.

A quick fix is to use some permatex #2 gasket maker on both sides of the head gasket. I did when i put my GT18 back together, used the old head gaskets and no leaks. It stays soft and flexible but seals well

TractorBob · 12-14-2010, 09:24 PM

Quote:

Originally Posted by GT_80

A quick fix is to use some permatex #2 gasket maker on both sides of the head gasket. I did when i put my GT18 back together, used the old head gaskets and no leaks. It stays soft and flexible but seals well

I never even thought of that!

I'm going to have to pick some up.

Thanks Bob

GT_80 · 12-14-2010, 10:02 PM

Quote:

Originally Posted by TractorBob

I never even thought of that!

I'm going to have to pick some up.

Thanks Bob

It's the cheapest gasket sealer they have too!!!

Tencubed · 12-14-2010, 10:21 PM

You can true up a small block using a big flat file. Just go slowly and hold the file good and flat to the block. I use a 2" wide by 16" long Mill Bastard that I got years ago for truing up castings. Having a good file brush will keep the file clean and sharp.

I'd suggest having the piston just below TDC and sealing it with grease. This will allow you to keep the filings from going down alongside the piston. What little grease is left between the piston and cylinder wall after the cleanup will dissipate shortly after startup.

Mike

JVHBRONCO · 12-16-2010, 03:26 AM

you have been given the same advice i would give.but ,i always use copper coat on my head gaskets i forgot to mention that in my last post. hope everything works out for you.

Kbeitz · 12-16-2010, 07:12 AM

If nothing in the way you can slide the glass plate on the block...

12-14-2010, 12:07 AM	#1
TractorBob Senior MTF Member Join Date: Mar 2010 Location: NH Posts: 323 MTF Member # 40681	What could be causing this? I just replaced the head gasket on my suburban about 2 weeks ago and it was running great. While I had the head off, I cleaned the carbon build up off the head and top of the piston and checked everything which looked to be good and healthy. There was no scoring in the cylinder and the valves seemed tight, without taking the valve spring inspection cover off. Today I noticed that it was leaking in the same spot again, just above the carb. I was degreasing the motor and sprayed some soap and thats when I noticed it was bubbling out. I tightened the head bolts down and it was still bubbling. I am going to pull the head off again tomorrow and check it again. Hopefully there are not any cracks anywhere. __________________ 65 Sears Suburban 8 HP w/ 10 HP repower (The Old Tractor) 72 Ford LGT125 (The Hydro) 74 Ford LGT100 (The Ford) Johnson FEL 48" Dozer 48" Mid grader 50" Mower 42" snowthrower 86 F350 1 tn PU 4x4 03 Dodge Durango 4x4 "There is a sickness worse than alcohol and dope, it is the tractor debt, and there is no cure in sight."

12-14-2010, 05:56 AM	#3
JVHBRONCO DEERE & SEARS CRAZY!!! Join Date: Apr 2007 Location: LAKE ISABELLA,CA Posts: 65 MTF Member # 5655	Re: What could be causing this? did you check the head and block with a straight edge? may need to resurface one or the other or both....most of the time it is just the head needs resurfaced.not hard to do.

12-14-2010, 06:31 AM	#4
Kbeitz Collector of many tractors Join Date: Mar 2005 Location: Northeast Pennsylvania Posts: 11,677 MTF Member # 86 Images: 4	Re: What could be causing this? Glue a sheet of sandpaper to a sheet of glass... Rub head on paper... Any low or high spots will show it's self ... __________________

12-14-2010, 04:39 PM	#5
TractorBob Senior MTF Member Join Date: Mar 2010 Location: NH Posts: 323 MTF Member # 40681	Re: What could be causing this? I am going to try the sandpaper idea now. I'll let you know how I made out. Thanks Bob __________________ 65 Sears Suburban 8 HP w/ 10 HP repower (The Old Tractor) 72 Ford LGT125 (The Hydro) 74 Ford LGT100 (The Ford) Johnson FEL 48" Dozer 48" Mid grader 50" Mower 42" snowthrower 86 F350 1 tn PU 4x4 03 Dodge Durango 4x4 "There is a sickness worse than alcohol and dope, it is the tractor debt, and there is no cure in sight."

12-14-2010, 08:40 PM	#6
TractorBob Senior MTF Member Join Date: Mar 2010 Location: NH Posts: 323 MTF Member # 40681	Re: What could be causing this? Sandpaper worked on the head. It was all twisted and warped. I put the head back on sprayed some soap around the head gasket and cranked it over and it is still bubbling. How do I resurface the cast iron block? I pulled the motor and am going to start cleaning all the built up oil and dirt off it. I am even thinking of repainting it. __________________ 65 Sears Suburban 8 HP w/ 10 HP repower (The Old Tractor) 72 Ford LGT125 (The Hydro) 74 Ford LGT100 (The Ford) Johnson FEL 48" Dozer 48" Mid grader 50" Mower 42" snowthrower 86 F350 1 tn PU 4x4 03 Dodge Durango 4x4 "There is a sickness worse than alcohol and dope, it is the tractor debt, and there is no cure in sight."

12-14-2010, 10:21 PM	#10
Tencubed 3K Poster!!!! Join Date: Aug 2009 Location: Washington Posts: 4,326 MTF Member # 31735	Re: What could be causing this? You can true up a small block using a big flat file. Just go slowly and hold the file good and flat to the block. I use a 2" wide by 16" long Mill Bastard that I got years ago for truing up castings. Having a good file brush will keep the file clean and sharp. I'd suggest having the piston just below TDC and sealing it with grease. This will allow you to keep the filings from going down alongside the piston. What little grease is left between the piston and cylinder wall after the cleanup will dissipate shortly after startup. Mike __________________ A gun and a parachute are much the same. When you need one nothing else will really suffice.

12-16-2010, 03:26 AM	#11
JVHBRONCO DEERE & SEARS CRAZY!!! Join Date: Apr 2007 Location: LAKE ISABELLA,CA Posts: 65 MTF Member # 5655	Re: What could be causing this? you have been given the same advice i would give.but ,i always use copper coat on my head gaskets i forgot to mention that in my last post. hope everything works out for you.

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12-16-2010, 07:12 AM	#12
Kbeitz Collector of many tractors Join Date: Mar 2005 Location: Northeast Pennsylvania Posts: 11,677 MTF Member # 86 Images: 4	Re: What could be causing this? If nothing in the way you can slide the glass plate on the block... __________________

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