2001 Marquis Jasper leveler question

[Peter Buenting]

I’m looking for some troubleshooting information for our SMC leveling system. When activated it does the air dump then it sounds and feels like the drivers side front deploys and makes contact.  The passenger side front seems to be the next one to deploy but the pump just runs and runs, no contact. The front right also seems to partially deploy while driving. I turn on the system and after it does it’s usual initialization I can retract it (them?) and it will be fine for awhile.

How do you guys get under this beast to look at things after an air dump?  I’ve located the manifold and coils. The oil level is only about a half inch down from top of tank.

What next?

Thanks in advance for any assistance.

[David Ciotti]

On my 2002 Marquis the front right wheel has to be removed to get a good look at the hydraulic leveling jack.  I am in the middle of trying to repair a leaking jack, and will keep you informed.

[Eric Maclean]

Peter
From your description it sounds like you have a problem with the passenger side front extend valve at the hydraulic manifold
Possibly a broken O ring on the valve or the valve and or solenoid failure.
The fact that it creeps down would lead me believe an O ring which allows hydraulic fluid to bypass and not build pressure to extend or take weight if this is the case the jack should still move downward when activated but not bare any weight.
I believe the SMC system uses dual acting cylinders which means they are powered both up and down this means in order to extend or retract the solenoid valves have to open one  hose to allow fluid to enter one side of the cylinder and the other hose to allow fluid to return to the reservoir.
Knowing that it makes sense that if an O ring where to break in the valve for the upper hose or extend hose end the fluid would be allowed to return to the reservoir internally in the manifold instead of pressurizing the cylinder if this is the case the pump should run freely.
The other scenario  ( not likely as both halves of the valve work together ) is that the extent portion of the valve is intact and working but the return portion of the valve is not opening  in this case the extent end of the cylinder will pressurize but the retract end can not exhaust the fluid traped in it and the cylinder will be dead headed and not move . In this scenario the pump will be working hard as the pressure will climb to the relief valve setting and be bypassed to the reservoir.
The third scenario is a blown seal in the cylinder itself. In this case the valves are both working as intended but the fluid is bypassing from one side of the cylinder to the other and returning to the reservoir. In this scenario the pump will run fairly freely depending on the extent of the seal damage there will be some movement but no ability to lift any weight.

The place to start is to activate the effected cylinder and watch and listed to see what movement there is if any and the amount of effort it takes from the pump to get that movement.also listen to hear if the valves are working ( clicking when activated )

Check the valve coil wiring with a test light when activated to verify there is a signal coming from the leveling controller .
Also make certain the coils works by disconnecting and feeding 12 volt to see if they do activate the valves listening for the click.
NOTE: DO NOT FEED POWER TO A COIL UNLESS IT IS ON A VALVE doing so will burn up the coil.
            DO NOT feed power to the coils with them in the circuit as this may back feed and damage the leveling controller.

The next thing to do is remove the valves for the effected cylinder and inspect the O rings for damage. ( cuts or breaks )
Any hydraulic shop should be able to match the O rings if necessary
This would be my guess and the first place I'd look

In the coach assist library there is an SMC leveling manual with limited information  but it may help identify the valves and hose ports on the manifold it also has a small section at the very bottom of the page which may be helpful for diagnosing the valves.

Hope this helps
Eric

[Peter Buenting]

Thanks Eric. The pump seems to run fairly freely so I’m thinking the o-ring suggestion might be the ticket. I have that manual for the levelers but it didn’t have much information but does identify the various coils and valves. I’ll do some further testing based on your thoughts.

Do the jacks deploy in sequence?  If the right front isn’t bearing any weight the controller won’t move on to the next one?  Does that make sense? All 4 probably need to make contact before starting to lift?

[Eric Maclean]

Makes sense but I'm Not sure of the logic which SMC programed into the system maybe someone with a working SMC system can chime in here

[Steve Huber Co-Admin]

Peter,
Have you tried using the semi-automatic mode as described in the owners manual since doesn't rely on sequencing of all 4 jacks?
Steve

[Peter Buenting]

I haven’t. Good idea.

[David Ciotti]

I took my 2002 Beaver Marquis to Mercer Spring and they removed the very leaky leveling jack and returned the jack and the Beaver to me.  I took the jack to Creston Hydrolics and they said the jack is a sealed unit and must be machined to access the innards to rebuild the jack.  They found a shop with a repaired jack in stock and will sell it to them for ~ $1500 and they want the old jack back for the core value.  I am waiting for the jack, when it arrives I will bring it and the Beaver back to Mercer Spring for installation.  This is in the Trenton area of New Jersey.

There is another thread discussing my problem called Wheel Bearings because when I initially saw the fluid on the ground around the right front wheel in Lake George New York I thought it was a wheel bearing leak.  Then I thought it was a brake fluid leak then a mechanic crawled under the RV and told me I had a leveling jack leak.

More to follow...

[David Ciotti]

I have received the repaired jack, BeaverCoachSales has 8 in stock.  Now I am waiting for a bay at Mercer Spring for a slot to replace the leveler.

[David Ciotti]

Final Post on the repair of the front right leveling jack on my 2002 Marquis.

A spot opened at Mercer Spring (MS) for reinstalling the refurbished leveling jack from BeaverCoachSales through Creston Hydrolics.  I pulled my RV into a bay at MS for the installation.  The tech said he went down into the pit under the Beaver, installed the jack, and taped up the "All Up" wires which were eliminated from the refurbished jack.  I took the RV home and added 1 quart of DexronIII ATF.  The coach would not level completely.  Let the coach back down, added another quart of ATF and the coach did better but not quite level.  Let it down again, aired the coach up, added another quart of ATF and success the coach is level.

So the process took weeks because I thought the wheel had to be removed to access the jack, it does not.  The cost was around $2000 but I think it could be lower if I had the jack in hand so the old jack could be removed and the new jack installed all in one trip.