Sounds right.
Good luck with all that. Most of the injectors we see from MANs are badly corroded. More often than not the nozzle retaining nuts have to be replaced because they split.
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Thread: Fuel Injector service
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Re: Fuel Injector service
--- The poster formerly known as Scrod ---
I want to live in Theory, everything works there.
1970 36C375
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Re: Fuel Injector service
I do almost all of my own work on everything from HVAC to engine rebuilds and seldom have any trouble tackling something new, however I may need to rethink this subject since the impact (pun intended) of a mistake is big.
Thanks again.
GeorgeFlorida
2002 Cabo 47
MAN mechanical 800/8's
"You can avoid reality, but you cannot avoid the consequences of avoiding reality"
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Re: Fuel Injector service
As long as you exercise some judgement I don't think it would hurt to at least try. They may surprise you and come out without too much trouble. If they don't then you can consider farming it out.
--- The poster formerly known as Scrod ---
I want to live in Theory, everything works there.
1970 36C375
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Re: Fuel Injector service
When the tools come in I'll go down there, take the fuel rails off of the most accessible bank and try one that's easy to get to.
One last thing. Is twisting the body in the bore while trying to get it out of the head/block after the castle nut comes out a good thing or a bad thing? IOW, is it a uniform press fit into the bore or are there pins, or flats, etc?
Thanks,
GeorgeFlorida
2002 Cabo 47
MAN mechanical 800/8's
"You can avoid reality, but you cannot avoid the consequences of avoiding reality"
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05-11-2017 07:29 PM #25
Senior Member
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- Jun 2007
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Re: Fuel Injector service
George: No twisting. They'll have some kind of alignment pin or ball. You may be able to wiggle them a tiny bit which can help work penetrating oil in. BTW, these issues are not unique to MANs. We see it on Volvo's and other makes too. A lot of it has to do with the injector configuration and probably how long they've been in service and conditions in the engine space. I wouldn't assume they're one with the head, it's just something that can happen. Either way they have to be looked at sometime. Better sooner than later.
Krush: I'm with you 100% . I think the big concern is the fixing after the breaking. I don't want to think about what a head on one of those things costs. We both have a lot of experience with damage control on jobs like this. I don't know how much other people do and try not to make assumptions.--- The poster formerly known as Scrod ---
I want to live in Theory, everything works there.
1970 36C375
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Re: Fuel Injector service
I think I have the whole picture now.
Iv'e done my share - alternators, charging system redesigns, coolers, water pumps, fuel delivery modifications, HVAC rebuilds ..... I'll decide after the first couple whether it's gonna be me or a mechanic on this one. The banks on the outboard side alone could break my spirit. 25 years old does pretzel better than 63 year old most times so we'll see. I am more stubborn than most which can compensate some.
Thanks again, I'll report back.
GeorgeFlorida
2002 Cabo 47
MAN mechanical 800/8's
"You can avoid reality, but you cannot avoid the consequences of avoiding reality"
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Re: Fuel Injector service
I finally received my special MAN/Mercedes fuel injector tools (one came from England). The set up is that a sleeve/socket fits over the injector body with a castle nut drive at the bottom and an attachment for the fuel line threads at the top (and the ability to draw them together). Do you know if the idea is to cinch everything up and exert upward pressure to remove the injector body while unscrewing the castle nut at the head (bearing on both sets of threads) or remove the castle nut, bear down on the head and then attach at the fuel line threads and pull the body up (bear down on the fuel line threads only)?
For the slide hammer approach that seems more obvious. You remove the castle retaining nut, attach at the fuel line threads and apply shock upwards. If I have that correct then in that case all of the force is exerted on the fuel line threads. Buggering those up would be bad but as you stated earlier, buggering up the head threads as could be possible in the first case above would be, well ...
Thanks,
GeorgeFlorida
2002 Cabo 47
MAN mechanical 800/8's
"You can avoid reality, but you cannot avoid the consequences of avoiding reality"
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Re: Fuel Injector service
If the tool fits the castle nut you're not going to have anything to force against if you take the nut out.
You could try to find a compromise by putting the force on the injector line thread, but they're fairly short and you need enough engagement to prevent the threads from pulling off. You're probably going to end up using the castle nut to do the heavy lifting. It has bigger threads and can handle more force. Again, if it's an option I would pull the castle nut out first, clean the threads and use plenty of lubricant to prevent galling, then reinstall it and use it for forcing.--- The poster formerly known as Scrod ---
I want to live in Theory, everything works there.
1970 36C375
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Re: Fuel Injector service
I got the first one out quite easily. I set the socket up on the castle nut, cinched the top threaded assembly down onto the fuel fitting threads and unscrewed the castle nut while I held the injector body in place with the Allen socket on top. The previous mechanic really lathered everything with a very thick anti seize compound. If I get any that are tougher to remove I'll do what you said and dress the castle nut threads first. That tool is the s;/$. BTW, the injectors are indexed with a pin so twisting would in fact be bad.
Now it's off to find the funky fuel line wrenches that I need to get all 8 of them out. Thanks,
GeorgeIMG_6943.jpgLast edited by Reefgeorge; 05-22-2017 at 08:45 PM.
Florida
2002 Cabo 47
MAN mechanical 800/8's
"You can avoid reality, but you cannot avoid the consequences of avoiding reality"