M1078 LMTV Cab raising

what would happen if the lift piston was seized?

Pump would be struggling, pumping very slow if at all.

And you also would not be able to use hand jack, it
Would jack a little then you would not be to go any more.

I would like to Know why you haven't tried the tire lift. If it works then pump is ok.

Coffey1 said:

I would like to Know why you haven't tried the tire lift. If it works then pump is ok.

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In post 18 he says he did try it. Twas a no go.

Thanks I miss the post.
**** bi focals. Lol

I guess it's possible both are locked .

My thought would still be to rebuild the pump, as the first option. If the pump seals are bad, it's possible that it would pump fluid with the hose off (no backpressure resistance) but that when trying to lift an actual load it would not be able to generate enough pressure and the fluid would just flow through the bad seals.

Yes rebuild pump first it's fairly easy and cheap.
Usually when the pumps bad it'll be spraying oil out that vent on top of it and it'll be oily mess up there.

Okay-- last ditch effort.... if hydro pump is bad what if I disconnect the pressure and return lines and joint them together to bypass the pump and see if the manual pump works? that would rule out a bad pump or pump seal right?

update- still wont build pressure but I do notice the cab latch is dripping from the "indicator" pin. I'm gonna call SPX and try to rebuild the pump.

The manual pump should work where the pump is operational or not

OKAY! upon further review. The 2 lines on the hydro pump were reversed. Not sure who in Tennessee unhooked them but they are on the correct way and everything works as it should. Now I have to go find the three wrenches I threw in the woods! Thanks for all the help and input guys! have a good weekend

-Eric

So how did you surmise they were reversed? What clued you into that?

I read on another post on this site that someone had a similar issue and as being a mechanic myself I have messed up quite a lot so I figured there was a possibility. Everything is labeled now for the future. The cab lock is still dripping with the raise and lower valve but I can deal with that.

We plan on using this as a water rescue vehicle. We have used the older 5 tons for years with minimal issues as those are bullet proof! Any suggestions with the LMTV's? Yes it is salt water. Besides undercoating and good cleaning after storms any suggestions? Raise exhaust up a few inches. Zip tie breather lines for axles/ rear ends.

emndive said:

....We plan on using this as a water rescue vehicle. We have used the older 5 tons for years with minimal issues as those are bullet proof! Any suggestions with the LMTV's? Yes it is salt water. Besides undercoating and good cleaning after storms any suggestions? Raise exhaust up a few inches. Zip tie breather lines for axles/ rear ends.

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If I recall correctly word is the pre 1998 trucks got ZERO rust proofing. And of course everything on the internet is the truth..... so just for ****z and grins... Over do the rust proofing on this truck.. or plan and spend $$ with intent for it to have a short life.

Add a locker to rear. (only detroit locker is available) the AWD is sweet but without locker it will suck in environment like water rescue. Just a bit better than 2wd without locker. 4wd with selectable locker is best but unfortunately not an option on these trucks (yet).

coachgeo said:

If I recall correctly word is the pre 1998 trucks got ZERO rust proofing. And of course everything on the internet is the truth..... so just for ****z and grins... Over do the rust proofing on this truck.. or plan and spend $$ with intent for it to have a short life.

Add a locker to rear. (only detroit locker is available) the AWD is sweet but without locker it will suck in environment like water rescue. Just a bit better than 2wd without locker. 4wd with selectable locker is best but unfortunately not an option on these trucks (yet).

Click to expand...

I fluid film the $hit out of all my equipment once a year and every thing has held up beautifully. It’s a rust preventative/ lubricator. Designed for navy and nasa, it must be good!

emndive said:

I fluid film the $hit out of all my equipment once a year and every thing has held up beautifully. It’s a rust preventative/ lubricator. Designed for navy and nasa, it must be good!

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Thanks for info on fluid film... have heard of it but not researched so did just now.

. Corp. info says one gallon will do three semi truck underbodies? https://www.fluid-film.com/trucking-applications/
. recommended applicator info http://www.kellsportproducts.com/Spraygun.html
. Amazon price One gallon $34.00 w/free shipping https://www.amazon.com/Fluid-Film-P...pID=51AbYHaO5SL&preST=_SY300_QL70_&dpSrc=srch

Thank you for your response. I might have a low hydraulic fluid issue w/manual pump. I followed up NDT's suggestion & it worked perfectly in addition to resolving my fuel issue. Thanks again.

I followed your suggestion & it worked perfectly. Serviced my fuel issue & I am now happy like Gomer Pyle: "Thank ya, Thank ya, Thank ya"! I appreciate your assistance.

coachgeo said:

If I recall correctly word is the pre 1998 trucks got ZERO rust proofing.

Click to expand...

They were rustproofed but not very well. There was also an option for the earlier trucks to have additional rust proofing. One problem was the undercoating was water soluble.