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Somebody has to do it, and nobody else volunteers: the fixing saga

skyking1

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Nov 3, 2020
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I found the leak!
It was right there in front of me the whole time. I just needed to clean the engine off.

I'm a little ticked at my truck shop for not looking at all. Oh well. I'm not going to blow him up about it because I need their help and I'm not going to be that guy.
I have no idea if I can fix this one without their help.
I'm hoping the pros with these engines will come along and tell me what I can and can't do.
;)
 
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skyking1

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I'm completely without a clue there. What does the job take in terms of tools?
Is it something I should do or or should I take it down to my truck shop and let them handle it?
 

Truck Shop

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I'm completely without a clue there. What does the job take in terms of tools?
Is it something I should do or or should I take it down to my truck shop and let them handle it?
Attachment to hold bonnet, timing pins, probably ought to ask JC. Will need to remove air compressor.
 

skyking1

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I don't know man. He said something about timing with a drill bit :p
I asked, we'll see what he says.
EDIT:
Just for grins I called my truck shop.
He insists that there is no oil there. It's only fuel and he has no idea why there's oil up there and he thinks something's pretty messed up.
He said about 5 hours to change that one seal.
 
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skyking1

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John's all backed up so I'm on my own here. I have a call into another truck shop that might know what to do.
 

skyking1

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Yeah I didn't know what I was looking at. It's just a fuel leak and it isn't number four. It's running back from number three.
I don't know why it was hanging on the engine oil pan and looking like oil. Apparently it picked up enough crap along the way.
 

Truck Shop

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Yeah I didn't know what I was looking at. It's just a fuel leak and it isn't number four. It's running back from number three.
I don't know why it was hanging on the engine oil pan and looking like oil. Apparently it picked up enough crap along the way.
That's fairly common, just age and one of the service items about a cat injection pump.
 

Mobiltech

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5 hours should do all 6 and remove install air compressor along with that time.
You do need some special tools along with someone who knows their way around a fuel pump. Cleanliness is extremely important.
 

Acoals

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I bet the 3406 in my old Ford leaks worse than yours does . . . :D
 

skyking1

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no, you'd lose that bet. This made a drip drip drip everywhere I went. In the parking lot the sheen circles are 6' apart at the most. On the jobsites with standing water, it was all rainbow all the time.
 

Simon C

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Rocky Mountain House , AB., Canada
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I was told that these bonnets can be changed without the powerful spring compressor. Each unit powers the fuel up to the injector at the top of the fuel pump cam lobe. If you remove them when they are on the respective cylinders when on the top of overlap of engine valves on that cylinder, there isn't the spring force to overcome. You have to turn each cylinder to top of exhaust stroke on valve overlap to do the corresponding injection pump plunger. You are therfore doing the job on the base circle of the cam and not on the top.
1 Guy told me that was how he did it, I did not see it but seen the pump repaired.
What are your thoughts Truck Shop .
Simon C
 

skyking1

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washington
I got the truck back today, the bonnets all sealed up. I took some time to clean up the engine again and ran it for 20 minutes. No oil made it to the bottom of the pan.
It is not pristine but it is not dripping anywhere. I am confident I can give it a quick wipe and take it into a sensitive jobsite, once I deal with the dump cylinder leak.
I will make a drip tray for that. There is no fixing that leak without major bucks.
 

skyking1

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next job, air leak at the fan clutch.
When I shut down you can hear that leak above any other. I don't know if the problem is with that clutch or with the valve on the engine that controls it. The control is below/behind the alternator on the right side of the engine.
 

Acoals

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next job, air leak at the fan clutch.
When I shut down you can hear that leak above any other. I don't know if the problem is with that clutch or with the valve on the engine that controls it. The control is below/behind the alternator on the right side of the engine.

I have had consistent problems with the thermostatic fan control valve on the engine leaking air on my truck. My truck is a '92 L9000 with the 3406b. The valve is in the same location you describe. I have replaced it but it still leaks intermittently when I shut the truck off as you describe. I replaced the air dryer last winter and it seemed like the intermittent leaking was somewhat improved last summer, but it's still an issue.
 

skyking1

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washington
What about putting a solenoid valve out in front of that whole setup, so when I key off it shuts off that leak?
 
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