stuck spare.

[Stixsmarsh]

I've searched high and low and haven't been able to find an answer to help me resolve this.
My spare carrier is stuck, and wont lower.
The cap works just fine, and hand and air over hydro pump function beautifully.
but when we try to operate the spare system the hand and air over hydro system is met with heavy resistance, the suspension system feels the same. tho thats less critical.
I have disassembled our control selection valves, and there is no obstructions there.
I have disconnected our ram from the system and fluid flows freely from the hoses at the ram. But seems to be blocked within the ram. maybe the safety valves. Ive attempted for a very long time to do seans trick of working the raise/lower knob back and forth while pumping and it has not improved.
seems like maybe the system needs to be bled of air but i havent found any good information on how to do that.
Any input would be greatly appreciated. Looking to start to travel soon, and not having a spare isnt a good idea.
Thanks in advance.

 

[Mullaney]

I've searched high and low and haven't been able to find an answer to help me resolve this.
My spare carrier is stuck, and wont lower.
The cap works just fine, and hand and air over hydro pump function beautifully.
but when we try to operate the spare system the hand and air over hydro system is met with heavy resistance, the suspension system feels the same. tho thats less critical.
I have disassembled our control selection valves, and there is no obstructions there.
I have disconnected our ram from the system and fluid flows freely from the hoses at the ram. But seems to be blocked within the ram. maybe the safety valves. Ive attempted for a very long time to do seans trick of working the raise/lower knob back and forth while pumping and it has not improved.
seems like maybe the system needs to be bled of air but i havent found any good information on how to do that.
Any input would be greatly appreciated. Looking to start to travel soon, and not having a spare isnt a good idea.
Thanks in advance.

Stranger things have happened, but does your spare carrier move a little - and then stop? I have seen the tire get stuck on top of the tool box and control box. The "stuck" has pushed the spare tire enough (on some trucks) to bend the metal on top the tool box.

There are also screens (orifice filters) behind all the knobs for the Spare, Cab, Air Bag, etc.



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[coachgeo]

I've searched high and low and haven't been able to find an answer to help me resolve this.
My spare carrier is stuck, and wont lower.
The cap works just fine, and hand and air over hydro pump function beautifully.
but when we try to operate the spare system the hand and air over hydro system is met with heavy resistance, the suspension system feels the same. tho thats less critical.
I have disassembled our control selection valves, and there is no obstructions there.
I have disconnected our ram from the system and fluid flows freely from the hoses at the ram. But seems to be blocked within the ram. maybe the safety valves. Ive attempted for a very long time to do seans trick of working the raise/lower knob back and forth while pumping and it has not improved.
seems like maybe the system needs to be bled of air but i havent found any good information on how to do that.
Any input would be greatly appreciated. Looking to start to travel soon, and not having a spare isnt a good idea.
Thanks in advance.

have you bled it by cracking the spare's OUT hose end where it attaches at the back of the manifold? then work your way up the line to the next hose end etc.

have you removed any of the individual valves to clean them.? Also there is a restrictor valve behind the hand valve in the manifold that sometimes gets plugged. while your in there might as well remove that too and use a micro piano wire to clean that out.

 

[Stixsmarsh]

Stranger things have happened, but does your spare carrier move a little - and then stop? I have seen the tire get stuck on top of the tool box and control box. The "stuck" has pushed the spare tire enough (on some trucks) to bend the metal on top the tool box.

There are also screens (orifice filters) behind all the knobs for the Spare, Cab, Air Bag, etc.

View attachment 824527

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pulled all the screens and even the small orifice screw behind, they all were impressively clean. the spare doesnt move at all, in either direction.

 

[Stixsmarsh]

have you bled it by cracking the spare's OUT hose end where it attaches at the back of the manifold? then work your way up the line to the next hose end etc.

have you removed any of the individual valves to clean them.? Also there is a restrictor valve behind the hand valve in the manifold that sometimes gets plugged. while your in there might as well remove that too and use a micro piano wire to clean that out.

i havent pulled any hoses from the back of the manifold. because i get flow at the ram side i figure that eveything was moving thought the manifold like it should. i did pull and clean all the valves, screens and orifice screw too.

does anyone know is the safety valve in the ram resettable or accessible after removing the hoses at the ram. when i did that with mine there is another screen, that is spring clipped inside the port. didnt seem easily removable.

 

[Ronmar]

Air is only really an issue when it is in a hydraulic pump. In a line or cylinder it simply compresses to whatever the fluid pressure is. Because it acts like a spring, it can add a spongy feel to manual systems and cause erratic operation as the air is allowed to expand.

the cab suspension cylinders have 2 locking pins each that physically lock the cylinder in the retracted position. They won’t move until those pins are removed.

for the cab and spare cylinder, the safety check components were installed in there some how. It looks like there is a SAE -JIC adapter installed in the cylinder Port. once the adapter is removed, The check assembly is behind that filter, so it would have to be removed. I would suspect some sort of spring cir-clip retaining the filter, then some type of orifice screwed into the threads. behind that a spring and a ball?

 

[Stixsmarsh]

Air is only really an issue when it is in a hydraulic pump. In a line or cylinder it simply compresses to whatever the fluid pressure is. Because it acts like a spring, it can add a spongy feel to manual systems and cause erratic operation as the air is allowed to expand.

the cab suspension cylinders have 2 locking pins each that physically lock the cylinder in the retracted position. They won’t move until those pins are removed.

for the cab and spare cylinder, the safety check components were installed in there some how. It looks like there is a SAE -JIC adapter installed in the cylinder Port. once the adapter is removed, The check assembly is behind that filter, so it would have to be removed. I would suspect some sort of spring cir-clip retaining the filter, then some type of orifice screwed into the threads. behind that a spring and a ball?

View attachment 824528

Thanks so much. I have a 16x2 ram on order. Tho ill dig deeper into our current ram tomorrow and see if I can get behind that filter. Its kinda a wide screen actually, if its a ball & spring wonder if I can free it with a pick through the screen? I'll report more tomorrow

 

[Stixsmarsh]

Well. Pulled the ram again. Double check that I have good hydraulic flow up until the point that it enters the ram and I do. Copious and consistent. I pulled the screen filter and cycled the valve several times at both ports. Reinstalled everything and still no ram movement. I tried cracking one line at a time at the ram to see if it was flowing through the ram but not pushing and wasn't able to get any flow through the ram. Seems that mine is shot.

We even tried cycling between raise and lower with the hand pump. We would go to raise pump till we had resistance, hammer on the area of the valves, switch to lower pump till there was resistance hammer and repeat. Hoping to free the blockage. No luck.

At this point I've ordered a replacement ram. $100. Will stay posted with how that goes.

Feeling defeated.

 

[Mullaney]

Well. Pulled the ram again. Double check that I have good hydraulic flow up until the point that it enters the ram and I do. Copious and consistent. I pulled the screen filter and cycled the valve several times at both ports. Reinstalled everything and still no ram movement. I tried cracking one line at a time at the ram to see if it was flowing through the ram but not pushing and wasn't able to get any flow through the ram. Seems that mine is shot.

We even tried cycling between raise and lower with the hand pump. We would go to raise pump till we had resistance, hammer on the area of the valves, switch to lower pump till there was resistance hammer and repeat. Hoping to free the blockage. No luck.

At this point I've ordered a replacement ram. $100. Will stay posted with how that goes.

Feeling defeated.

Would know how this all worked out. Would also like to see if you could disassemble the cylinder and "repack" it. You could sell it as a rebuilt or have it around the house for next time.

Seems that water collects in the hydraulic fluid on these trucks. Not much fluid in the reservoir, so not much water will cause a problem. It may be worth your time to look at the TM to see how often that fluid should be changed. If you haven't ever, it would be a cheap thing to replace...

I had been reading about the valves, hand jack and other component parts where the "ball and spring" will sometimes get rusted (stuck shut). That too might be worth looking as well. And you could have a hydraulic line that is slowly crumbling from the inside...

At least a hundred bucks is a lot less than some other things on these trucks.

Hopefully your new cylinder is the fix!

.

 

[coachgeo]

....Would also like to see if you could disassemble the cylinder and "repack" it....

pretty sure .... like other hydraulic cylinders on this truck the ends are welded. So unless you cut the ends off and re-weld back on... they are not serviceable.

 

[Mullaney]

pretty sure .... like other hydraulic cylinders on this truck the ends are welded. So unless you cut the ends off and re-weld back on... they are not serviceable.

Bummer. By the time it was shipped from Colorado, it would cost more than it would be worth to try to service it.
Thanks for the info coachgeo .

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[Stixsmarsh]

pretty sure .... like other hydraulic cylinders on this truck the ends are welded. So unless you cut the ends off and re-weld back on... they are not serviceable.

This is correct. The ram seems completely disposable in it's construction with zero way of dissembling it.
Even in the tech manuals when you get to the point I'm at the next line item is to replace the ram.

 

[Reworked LMTV]

This is correct. The ram seems completely disposable in it's construction with zero way of dissembling it.
Even in the tech manuals when you get to the point I'm at the next line item is to replace the ram.

Replace it.

 

[RRaulston]

Well. Pulled the ram again. Double check that I have good hydraulic flow up until the point that it enters the ram and I do. Copious and consistent. I pulled the screen filter and cycled the valve several times at both ports. Reinstalled everything and still no ram movement. I tried cracking one line at a time at the ram to see if it was flowing through the ram but not pushing and wasn't able to get any flow through the ram. Seems that mine is shot.

We even tried cycling between raise and lower with the hand pump. We would go to raise pump till we had resistance, hammer on the area of the valves, switch to lower pump till there was resistance hammer and repeat. Hoping to free the blockage. No luck.

At this point I've ordered a replacement ram. $100. Will stay posted with how that goes.

Feeling defeated.

I've been helping a friend get his hydraulics working and have the exact same issue. We installed a new hyd. pump and got the cab and kneeling cylinders working perfectly, then extended the tire ram and its stuck extended. Can't retract it. I removed his raise/lower valve (his A1 valve is different than my A0) and there is no orifice like mine. I thought for sure there would be a plugged orifice. Going to remove the cylinder lines and check the check valve next...

 

[GeneralDisorder]

I've been helping a friend get his hydraulics working and have the exact same issue. We installed a new hyd. pump and got the cab and kneeling cylinders working perfectly, then extended the tire ram and its stuck extended. Can't retract it. I removed his raise/lower valve (his A1 valve is different than my A0) and there is no orifice like mine. I thought for sure there would be a plugged orifice. Going to remove the cylinder lines and check the check valve next...

This thread has some good info on what may be occurring.

Lmtv 1078 spare tire lift cylinder stuck. Again

I’m on my 3rd lift cylinder and it got stuck just like the first 2. I can’t figure out what’s going on. I figured the first cylinder locked up so I bought another. Then it locked up after the 2nd down up cycle. So I got another one. It just locked up like the other 2 after one down- up. I have...

www.steelsoldiers.com

 

[RRaulston]

This thread has some good info on what may be occurring.

Lmtv 1078 spare tire lift cylinder stuck. Again

I’m on my 3rd lift cylinder and it got stuck just like the first 2. I can’t figure out what’s going on. I figured the first cylinder locked up so I bought another. Then it locked up after the 2nd down up cycle. So I got another one. It just locked up like the other 2 after one down- up. I have...

www.steelsoldiers.com

WOW! I searched and this thread didn't come up! I bet that's exactly what's happening! Thanks! I'm on it....

 

[Wingnut13]

In the ram there are check balls on each side, raise and lower. I had a similar issue after the P/O had rebuilt the pump. My ram extended a few inches and locked up solid. I had to pull the pins to remove the cylinder. Once it was out I pulled both fittings, screens? Then I was able to push the check balls with a small Allen wrench and move the ram to clear the old nasty fluid. Once that was all cleared out I reassembled and installed. No issues since then.

 

[Wingnut13]

Here is the contents of the spare tire lift cylinder. I thought that my cylinder must’ve had corroded internally, it wouldn’t move. Once I cleared out the old fluid, that was mystery mix of fluid…. It works!

 

[RRaulston]

Here is the contents of the spare tire lift cylinder. I thought that my cylinder must’ve had corroded internally, it wouldn’t move. Once I cleared out the old fluid, that was mystery mix of fluid…. It works!
View attachment 888719

Great photo!

 

[Ronmar]

Yea I did a utube video on this also. I think the biggest issue on these is trapped air.

Once it is compressed in the cylinder it acts like a spring and any air in the line or a leaking valve will allow that air to force fluid out fast enough to lock the ball.

I think the key to releasing these is to either:
A. Remove the fitting, screen and spring, then push the ball off the seat with a thin probe to release the stored pressure.

B. Pump in the opposite direction. This pressure should force the ball off of the seat. Then you must very very slowly release the pressure, so the trapped air pressure in the cylinder will force the fluid past the check-ball slow enough not to trip it.

I think the rotary control valve may have a dead/open spot in it so when you grab and twist to rotate it normally to the opposite position, it allows a brief period of high flow which re-locks that check-ball. I dont know if it can be rotated slow enough to release the pressure slow enough, maybe… Another way might be, that once pressurized which should release the ball, you slowly crack a fitting and let the fluid slowly drip out until all the pressure has escaped. this should leave the ball in the neutral position and allow the cylinder to move normally…