Hurricane Helena LMTV Flooded

[TylerEMS]

Hey Guys, I need some big time help here... my 1999 M1078 LMTV project truck was parked and it was submerged in about 5ft of river water for about 24hrs (I was out of the State at the time) during Hurricane Helene. As we know, it doesn't say much about flooding in the TMs as to what to do in the aftermath of a deep submersion.

So far, I have drained the fuel tank (rubber filler cap didn't seal well, so tons of water got in), drained the air intake tube that was not connected to the air box (was working on it), removed fuel filters and blew air through the fuel lines back towards the tank...
My biggest concern is that I think river water got into the Turbo a few inches because of not having an air box on at the time... The water line appears to have gone a few inches up the "snail shell" housing, and I see a tube going down into the engine block (see pic)...

Any reccomendations on what damage could be caused if water got in the turbo? Besides what I have done so far, an oil change, and replacing the batteries... What are my greatest concerns? What else needs to happen? I'm not worried about the axels just yet, I will drain the pumpkins later and replace fluid, for the water went over the breather tubes. It does not appear the water got to the electronics in the cab, maybe about 7 inches of water intrusion on the floor of the cab.

This storm damage has depleted my funds to near zero, so getting this thing up and running again has to be done super cheap (and it needs to be moved from storage asap). If anyone has any filters or batteries they want to throw my way, I won't say "No" to, and could pay you back in a few weeks once I get insurance money for my Jeep that is a Total Loss. Or if there are any LMTV experts in the WNC area (I'm in Brevard, just south of Asheville), I could really use some help if you're available. Thanks for everyone's constructive input and understanding in this situation and these hard times... Semper Fi.

 

[TylerEMS]

Oh yeah, I forgot about the Alternator... I assume this costly little gem also needs to be replaced too... Should I switch to the civilian version and make the brackets? I know I can't afford a new OEM alternator... Just simply out of the question financially right now... Suggestions?

 

[Ronmar]

There is a little air cap/vent on top of the trans housing. If water got that high, the trans probably has water in it. Do not roll over the engine or trans until you confirm no water in their oil. Water kills the clutch plates. First check the dipsticks for excessive level, then drain the sumps.

water in the turbine and compressor housings shouldn’t be much of an issue. Remove the intake and outlet fittings and you can slide a paper towel down between the blades to wick the water out and/or apply heat to the housings to evaporate it. if it reached the height of the shaft it may make its way into the core, but that should be OK if the turbo wasnt leaking any oil. The turbine wheel should turn freely.

at 5’, just about every other vent went under water, so brake chamber vents are probably full(disconnect them at the brake chambers, and blow the lines clean). drain some axle oil and look for water. The brake actuators will ultimately need to be stripped, cleaned and greased.

starter probably got flooded, probably should pull it apart and inspect and lube. was the bell housing drain plug in or out? If it was in, open it and let any water out…

good luck, you got your work cut out for you

 

[GeneralDisorder]

Change all the fluids.

Alternator should be fine. That's the whole point of the Niehoff brushless design - it's dust/water proof since it is completely sealed and submersible. Clean all the connections of salt water and residue of course.

 

[NDT]

Alternator is submersible. It should be ok.

 

[Jbulach]

All good advice above… With lack of funds and likely time, the very first thing I would do before moving or cranking the truck and mixing the water into the oil, would be to crack every oil drain plug, or low resivor line (engine, trans, axles, air compressor, power steering, hydraulic ect)until the water stops running out and you start to see oil. If you don’t have mud intrusion the quicker you can get the fluids “cleaned up” and the truck running and moving the better. As long as the air compressor didn’t ingest water I wouldn’t spend too much time or $ on the air system yet. Starter will likely be fine if it cranks and you can get the truck through a couple of heat cycles will help dry it and everything else out.

 

[Jbulach]

I would also roll the motor over by hand before you do finally crank it to be certain not to hydrolock it.

 

[TylerEMS]

There is a little air cap/vent on top of the trans housing. If water got that high, the trans probably has water in it. Do not roll over the engine or trans until you confirm no water in their oil. Water kills the clutch plates. First check the dipsticks for excessive level, then drain the sumps.

water in the turbine and compressor housings shouldn’t be much of an issue. Remove the intake and outlet fittings and you can slide a paper towel down between the blades to wick the water out and/or apply heat to the housings to evaporate it. if it reached the height of the shaft it may make its way into the core, but that should be OK if the turbo wasnt leaking any oil. The turbine wheel should turn freely.

at 5’, just about every other vent went under water, so brake chamber vents are probably full(disconnect them at the brake chambers, and blow the lines clean). drain some axle oil and look for water. The brake actuators will ultimately need to be stripped, cleaned and greased.

starter probably got flooded, probably should pull it apart and inspect and lube. was the bell housing drain plug in or out? If it was in, open it and let any water out…

good luck, you got your work cut out for you

That was great info and some things I didn't even think about, thank you! I will check to see if the trans plug was in or not... Hopefully it was, but we will see. I will get started today on checking/draining all the different oils and such... Thanks again!

 

[GeneralDisorder]

That was great info and some things I didn't even think about, thank you! I will check to see if the trans plug was in or not... Hopefully it was, but we will see. I will get started today on checking/draining all the different oils and such... Thanks again!

The transmission body has a breather that is located more or less right below the PPD/LBCD behind the spare tire carrier. It's easiest to access with the spare tire lowered. It is NOT extended to the height of the front hub/axle and bell-housing breathers since it's screwed directly into the transmission and doesn't have an extension hose.

https://www.dieseldash.com/23047102-allison-transmission-oil-breather-assembly

The bell-housing breather is behind the cab zip tied to the spare tire frame. Typically the fording plug is not installed unless you are going into high water. But maybe you got lucky and it was already plugged.

 

[TylerEMS]

The transmission body has a breather that is located more or less right below the PPD/LBCD behind the spare tire carrier. It's easiest to access with the spare tire lowered. It is NOT extended to the height of the front hub/axle and bell-housing breathers since it's screwed directly into the transmission and doesn't have an extension hose.

https://www.dieseldash.com/23047102-allison-transmission-oil-breather-assembly

The bell-housing breather is behind the cab zip tied to the spare tire frame. Typically the fording plug is not installed unless you are going into high water. But maybe you got lucky and it was already plugged.

I got lucky, the plug is in with the breather tube above the high water line! One piece of good news! The plug was on there tight, I checked... So at least I don't have to drain and redo the transmission fluid... Thanks for your help!

 

[Ronmar]

I got lucky, the plug is in with the breather tube above the high water line! One piece of good news! The plug was on there tight, I checked... So at least I don't have to drain and redo the transmission fluid... Thanks for your help!

no, the bell housing vent is a hose up alongside the arch that supports the cab latch. There is a small round metal cap breather/vent screwed into the top of the main transmission case, about 18" aft of the bellhousing/cab arch. It is only marginally higher than the top of the upper chassis frame rail

General showed a picture of it unscrewed from the transmission case in the previous post. As he said, it is easiest accessed in between the spare tire and airfilter. I will shoot a pic of its installed position when i get home as mine is out in the open and easy to access. If the water got up above the frame rails/to the top of the bellhousing, that vent was underwater and could admit water directly into the main gearbox...

 

[Ronmar]

Here is the vent installed, under my dipstick tube. It is lower than the top of the bell housing…

 

[fuzzytoaster]

Lets take it step by step to the major decision making points for determining if the vehicle is worth the re-investment. I broke it down into 4 sections to help you put minimal time and money into the machine.

Disconnect batteries
Drain all fluids and I mean ALL fluids.
Open turbo intake and exhaust, and other systems to let water dissipate. If in doubt open a line and inspect contents. **Check weather before opening anything**
Attempt to rotate engine by hand to ensure no hydro lock. If hydro lock - STOP! Reassess engine for water intrusion. No hydro-lick - proceed.

Start tracing from the batteries looking for corrosion. Tend to it as discovered.
Install batteries and ohm out systems as needed.
Check for electrical power to systems and if computers are "happy" - DO NOT CRANK ENGINE!
If no power to systems then evaluate for potential cost of repairs vs value of vehicle.

Fill with the intent to flush transmission/transfer case and engine with 10w. **Best to do so after old fluids have stopped dripping into catch pan.**
If you feel the need to use an alternate fuel container for testing then do it.
Assess to see if it starts, runs, then transmission engages in gear. - If major electrical problems persist then put a 12v wire on the injection pump shut off solenoid from the battery and jump the starter at the starter relay (right of the power steering reservoir facing the engine - 2 larger threaded posts covered in silicone). If engine runs - continue electrical evaluation. If engine does not run - investigate lack of fuel prime, fluid contamination, or internal mechanical damage from water intrusion.

From there you'll be disconnecting brake lines to remove trapped moisture and moving on to electrical sub system tests that could go on for ages.. or not!

 

[Skyhawk13205]

Good video about a flooded truck.

 

[TylerEMS]

no, the bell housing vent is a hose up alongside the arch that supports the cab latch. There is a small round metal cap breather/vent screwed into the top of the main transmission case, about 18" aft of the bellhousing/cab arch. It is only marginally higher than the top of the upper chassis frame rail

General showed a picture of it unscrewed from the transmission case in the previous post. As he said, it is easiest accessed in between the spare tire and airfilter. I will shoot a pic of its installed position when i get home as mine is out in the open and easy to access. If the water got up above the frame rails/to the top of the bellhousing, that vent was underwater and could admit water directly into the main gearbox...

OK, I think I found the right one. It IS installed... So I should be OK then? I would really prefer not to have to drain the new transmission fluid if I don't have to... The water was probably over it for about 12-24hrs...

 

[GeneralDisorder]

OK, I think I found the right one. It IS installed... So I should be OK then? I would really prefer not to have to drain the new transmission fluid if I don't have to... The water was probably over it for about 12-24hrs...

NO! It's NOT a plug. It's an open breather port. If the water was over that point then the transmission is likely FULL of water.

That vent is where the transmission will puke out oil if it is overfilled.

You will likely ruin the transmission if you even start the engine with it full of water. The pump runs anytime the engine is running.

 

[TylerEMS]

Lets take it step by step to the major decision making points for determining if the vehicle is worth the re-investment. I broke it down into 4 sections to help you put minimal time and money into the machine.

Disconnect batteries
Drain all fluids and I mean ALL fluids.
Open turbo intake and exhaust, and other systems to let water dissipate. If in doubt open a line and inspect contents. **Check weather before opening anything**
Attempt to rotate engine by hand to ensure no hydro lock. If hydro lock - STOP! Reassess engine for water intrusion. No hydro-lick - proceed.

Start tracing from the batteries looking for corrosion. Tend to it as discovered.
Install batteries and ohm out systems as needed.
Check for electrical power to systems and if computers are "happy" - DO NOT CRANK ENGINE!
If no power to systems then evaluate for potential cost of repairs vs value of vehicle.

Fill with the intent to flush transmission/transfer case and engine with 10w. **Best to do so after old fluids have stopped dripping into catch pan.**
If you feel the need to use an alternate fuel container for testing then do it.
Assess to see if it starts, runs, then transmission engages in gear. - If major electrical problems persist then put a 12v wire on the injection pump shut off solenoid from the battery and jump the starter at the starter relay (right of the power steering reservoir facing the engine - 2 larger threaded posts covered in silicone). If engine runs - continue electrical evaluation. If engine does not run - investigate lack of fuel prime, fluid contamination, or internal mechanical damage from water intrusion.

From there you'll be disconnecting brake lines to remove trapped moisture and moving on to electrical sub system tests that could go on for ages.. or not!

OK, I think I found the right one. It IS installed... So I should be OK then? I would really prefer not to have to drain the new transmission fluid if I don't have to... The water was probably over it for about 12-24hrs...

Thank you so much, that is a great breakdown of the steps! Finishing draining the fluids today and will start on the electrical. I won't be able to test until Monday when I get the new batteries. Thanks you so much!

 

[TylerEMS]

NO! It's NOT a plug. It's an open breather port. If the water was over that point then the transmission is likely FULL of water.

Well crap, I guess all fluids need to be done...

 

[TylerEMS]

Well crap, OK. Will be draining the transmission and engine oil today, fuel is already drained, lines blown out, and 2 new fuel filters... Thanks for your guys help!

 

[Ronmar]

If it filled with significant water, the transmission dipstick should indicate this(will show it full of fluid well above the dipstick marks. Most anything on the truck can tolerate some water in it for a bit EXCEPT THE TRANSMISSION. The friction material on the clutch discs is bonded to with a water soluble adhesive, so any prolonged water exposure will destroy that bond and turn the clutch coating to mush… i would drain the trans ASAP If that vent went underwater!