Removing, rebuilding, reinstalling Hydraulic Head

GunInstructordotcom

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There is a good thread here about a leak from the top of the HH. That could be what is happening with mine. Apparently, the diesel can creep down the sides of the HH after leaking from the base of one or more injector lines. Since I reinstalled those old lines, that is a possibility. I'll check it out next week when I have the time.
 

Jeepsinker

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Wish I could help you. I've driven hundreds of miles to make repairs for lots of people. Unfortunately I'm on the other side of the globe for the foreseeable future.
 

GunInstructordotcom

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I took the rubber caps off the injector lines at the HH. While running, it is dripping about two drops every five seconds or so to the ground below the injector. Number 3 injector nut filled with diesel around the line and at the base where it meets the HH. So I'm assuming the ferrule is not compressed enough. I tried tightening it with an open end and it budged a tiny amount, but it still leaks. So at this point do I replace the injector line, which replaces the ferrule? I don't want to cut and use the patch fitting someone did on this forum. I'm barely treading water here as it is, so swapping parts is fine with me. But will that fix the leak, or can there be another problem I'm not seeing? Note - #3 is one of the two injector outlets on the HH where I discovered the orange rust-looking gunk at the bottom of the HH hole when I disassembled to replace the o-rings. I thoroughly cleaned the holes out with q-tips before reassembly.
 

cattlerepairman

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A burr at the ferrule can cause persistent leaking. You could polish the ferrule with fine sand paper or scotch brite, then blow the line through and clean the ferrule, put a dab of grease on it (to grease between the line and the nut) and reassemble. If it still is not dry, tighten a little more....like 1/16 turn at a time. Important to not over-tighten.
Also consider the possibility of a crack in the hydraulic head (usually hidden underneath the plate with the line numbers).
Good luck!
 

GunInstructordotcom

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A burr at the ferrule can cause persistent leaking. You could polish the ferrule with fine sand paper or scotch brite, then blow the line through and clean the ferrule, put a dab of grease on it (to grease between the line and the nut) and reassemble. If it still is not dry, tighten a little more....like 1/16 turn at a time. Important to not over-tighten.
Also consider the possibility of a crack in the hydraulic head (usually hidden underneath the plate with the line numbers).
Good luck!
I did consider the possibility that my original problem still is a cracked HH. When I had it off for the o-ring replacement I looked it over, but an untrained eye could miss the crack. A new set of injector lines is over $500, so I will try removing the #3 and inspecting the ferrule. I may have already over-tightened. But it cannot hurt to do what you advised and see if it stops leaking. I am blessed with it being #3 line, relatively easy-peasy. I suspect over-tightening can lead to a HH crack?
 

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When I removed the line today, the ferrule at the HH end was rough on the mating surface. Compared to the injector end surface, it was real rough. There was dirty diesel in the HH hole that I cleaned out with q-tips. This was one of the two holes that had the red sludge in it from the rubber covers being torn and water getting in when I snowplowed in years past. I ordered another line and will see what happens when I install it.
 

GunInstructordotcom

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I installed a NOS #3 injector line. The good news is that line no longer leaks at the HH. The bad news is I still have a decent diesel leak from somewhere under the side cover. Next chance I get to work on it, I will start it up and using a mirror, try to determine where the leak is coming from. I could have a cracked HH, or the side lever o-ring could be one of the ones that is a tad too large, causing a leak into the side cover. This is becoming a frustrating ordeal. I'm starting to think I should have driven the truck to a diesel mechanic and obtained a new mortgage on my house to pay the bill.
 

GopherHill

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Hiring out repairs is well and good IF the job is done correctly. I wouldn't think much expertise is out there for repairs on these trucks. So many resources are out there (and on this forum) so to educate yourself . The job will turn out better in most cases because you care about getting it right.
Just my opinion from the school of hard lessons ( and old age )
 

GunInstructordotcom

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Hiring out repairs is well and good IF the job is done correctly. I wouldn't think much expertise is out there for repairs on these trucks. So many resources are out there (and on this forum) so to educate yourself . The job will turn out better in most cases because you care about getting it right.
Just my opinion from the school of hard lessons ( and old age )
Here is where I'm at. I had a leak from the fuel injector pump area, dripping to the ground about one drip every few seconds. I replaced the three o-rings. Upon reassembly, I still had a leak from the fuel injector pump area, same volume. I noticed a weeping leak at the #3 injector line HH connection. I replaced the #3 line and that leak is gone. I still have the other leak, which appears to be coming from under the shutoff cover. Next I will remove the cover and see if there is diesel where there should only be oil. If there is, I can replace the small o-ring again and see if that stops the leak. The other problem I may have is a cracked HH. I may have missed a hairline crack when I had it off. If the small o-ring replacement does not stop the leak, I guess I have to remove the HH again and give it a careful examination.

The new Chinese HHs are still available at $500 from US sources. The Chinese company that makes them emailed me that they are out of stock and are having a materials supply shortage, so no estimate as to when they're back in stock. That would have been about $220.

Other than the small o-ring not sealing or a cracked HH, are there any other possible sources of the leak? I will check for leaks all the fuel line connectors that I removed and re-installed. Do I have to align the red tooth before I remove the shutoff lever shaft to replace the small o-ring again? Thank you for your advice. I'm trying to gain knowledge as I go through this.
 

NY Tom

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I installed a NOS #3 injector line. The good news is that line no longer leaks at the HH. The bad news is I still have a decent diesel leak from somewhere under the side cover. Next chance I get to work on it, I will start it up and using a mirror, try to determine where the leak is coming from. I could have a cracked HH, or the side lever o-ring could be one of the ones that is a tad too large, causing a leak into the side cover. This is becoming a frustrating ordeal. I'm starting to think I should have driven the truck to a diesel mechanic and obtained a new mortgage on my house to pay the bill.
Did you drive the truck after changing the line or just run it?
I had the same problem and it did not leak just running. Thought I was in the clear. Took it for a drive and the leak became apparent.
 
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