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Diesel leaking from new head

R

rdyfreddie

New member
Hi just had the 2 new heads fitted to 6VTA92 runs perfectly for a couple of minutes the diesel started coming out from head not injectors all looked good
Coming from one end
 
You are a little vague about where you see the leak. Are you seeing this leak while the valve cover is off or is it leaking externally and you haven't removed the valve covers?

If it's external and you didn’t take the valve cover off then it's probably where the fuel line connection fittings thread into the fuel manifold that's cast into the head.

If you're lucky, it's likely a cracked fitting or a poor seal between a fuel line and fitting.

The fittings are probably brass and they can crack easily. Also, the line to fitting "flare" surface can be easily damaged during handling and then not seal well. Hint: more tightening of a fuel line often just makes the leak worse.

If you are unlucky, someone may have overtightened a fitting and caused the fuel manifold threads in the head to crack. The tapered pipe threads will cause this sometimes when forced. If that happened then the head is likely junk and will need to be replaced. Although, I have heard of welding, re-drilling and
re-tapping the head working.

I hope you just have a cracked fitting (VERY common) or a poorly seated fuel line to fitting connection which is also fairly common.

Good luck.
 
Forgot to say don't run the engine if the leak is UNDER the valve cover as this will quickly dilute the engine oil and cause you other problems that you don't want.

Good luck.
 
jgmo said:
You are a little vague about where you see the leak. Are you seeing this leak while the valve cover is off or is it leaking externally and you haven't removed the valve covers?

If it's external and you didn’t take the valve cover off then it's probably where the fuel line connection fittings thread into the fuel manifold that's cast into the head.

If you're lucky, it's likely a cracked fitting or a poor seal between a fuel line and fitting.

The fittings are probably brass and they can crack easily. Also, the line to fitting "flare" surface can be easily damaged during handling and then not seal well. Hint: more tightening of a fuel line often just makes the leak worse.

If you are unlucky, someone may have overtightened a fitting and caused the fuel manifold threads in the head to crack. The tapered pipe threads will cause this sometimes when forced. If that happened then the head is likely junk and will need to be replaced. Although, I have heard of welding, re-drilling and
re-tapping the head working.

I hope you just have a cracked fitting (VERY common) or a poorly seated fuel line to fitting connection which is also fairly common.

Good luck.
Click to expand...
Got the Detroit engineer here Friday hopefully find and fix

Another mechanic said a seal fitted when manufactured might not be seated correctly and diesel leaking
Said might have to take head off
 
Under the head there is NO one piece "head gasket" as is often thought of with most piston engines.

Under the head are:

The compression gaskets...1 per cylinder.

Oil passage seals....several

Water passage seals...several

A "perimeter seal"...as much to keep stuff out as to keep stuff in

There are no seals for fuel under the head so not sure what that mechanic was referring to.

If you have a Detroit rep coming then he will probably figure it out in short order.

Good luck.
 
jgmo said:
Under the head there is NO one piece "head gasket" as is often thought of with most piston engines.

Under the head are:

The compression gaskets...1 per cylinder.

Oil passage seals....several

Water passage seals...several

A "perimeter seal"...as much to keep stuff out as to keep stuff in

There are no seals for fuel under the head so not sure what that mechanic was referring to.

If you have a Detroit rep coming then he will probably figure it out in short order.

Good luck.
Click to expand...
Thanks again

Il let you know
 
jgmo said:
You are a little vague about where you see the leak. Are you seeing this leak while the valve cover is off or is it leaking externally and you haven't removed the valve covers?

If it's external and you didn’t take the valve cover off then it's probably where the fuel line connection fittings thread into the fuel manifold that's cast into the head.

If you're lucky, it's likely a cracked fitting or a poor seal between a fuel line and fitting.

The fittings are probably brass and they can crack easily. Also, the line to fitting "flare" surface can be easily damaged during handling and then not seal well. Hint: more tightening of a fuel line often just makes the leak worse.

If you are unlucky, someone may have overtightened a fitting and caused the fuel manifold threads in the head to crack. The tapered pipe threads will cause this sometimes when forced. If that happened then the head is likely junk and will need to be replaced. Although, I have heard of welding, re-drilling and
re-tapping the head working.

I hope you just have a cracked fitting (VERY common) or a poorly seated fuel line to fitting connection which is also fairly common.

Good luck.
Click to expand...
Hi at to lift head 2 inches a plug was missing 5 minutes head back on
I realised after putting all back together left small oil overflow pipe off
Lifted the blower can't get in 1/4 inches left but won't go any further
Can I shorten pipe

Thanks
 
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