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05-05-2010, 08:21 AM
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#1
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Seasoned Camper
Join Date: Feb 2010
Location: Sterling
Posts: 85
M.O.C. #10132
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Hyd slides - what controls the ext/ret function?
I know the subject of slide problems has been discussed unendingly but i can't find any discussion specific to the problem I'm having.
Here's the problem: The slides on the hydraulic side sometimes don't retract when the switch is depressed. The pump's electric motor runs fine every time (its not the auto breaker problem that so many have). The hydraulic reservoir is full and no air is in the system. Also, the slides work perfectly every time when extending them so I assume the pump is working correctly. The problem only happens on retraction - and it's intermittent.
I thinnk the mechanism that redirects the hydraulic fluid (elect controlled valve?) is not funtioning properly. I don't know how to determine if it's the elect switching at the valve housing or the physical valve(s) that's causing this problem.
I did a continuity check of the wiring between the operator switch on the wall and the unit - all checks out well (if I understand it correctly). I jumped power between the positive terminal and each side of the switch assy on the pump housing - sometimes there's a 'clunk' (the valve repositioning?) but not always. Seems like I should be able to switch it back and forth and hear it but it doesn't happen always. Worn out valve? Worn out elect switch (or whatever moves the valve).
Can anyone explain how that system works? Anyone know an easy way to determine the what exactly to repair or replace? Anyone have experience with this particular problem? Any tips on disassembly/reassembly (Is this rebuildable or is it a remove and replace situation?)
I appreciate hearing from anyone with some technical knowledge of this system. thanks ahead of time....dan
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05-05-2010, 04:20 PM
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#2
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Montana Fan
Join Date: Oct 2009
Location: Wilsons
Posts: 404
M.O.C. #9833
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Dan,
I have not worked on my 2010 Monty's hydraulic system (yet), but . . . having worked in an industrial environment for a number of years - a "typical" setup has a pair of 2 pole switches on the control panel (wherever that might be) one for "in" one for "out" One contact on ,each switch, will be used to turn the pump motor on, the other contact operates a solenoid actuated valve that allows the hydraulic fluid, under pressure, into one end of the cylinder - left, right or in and out, or up and down - you get the picture. There are several ways to allow the downstream fluid to return to the reservoir and not having delved into this system I dunno what method they use here. One thing you can do is have someone observe the reservoir when you hold the button, trying to make it move in the direction it doesn't want to go. If you see a steady stream of fluid flowing back into the reservoir then probably the rubber "cup" in the cylinder has blown out. If the motor sounds fine when running in the direction that works but sounds like it's stalling in the direction that doesn't work then the valve (whether by bad coil on the solenoid or stuck shuttle in the valve actuator (trash in the fluid can cause this) is not allowing the fluid to the operable end of the hydraulic cylinder - or - (doncha hate the "ors"?) that "return" we touched on earlier make be obstructed so the cylinder won't move 'cause there's noway for the fluid to return to the reservoir.
Hope this helps.
Jerry
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05-05-2010, 04:33 PM
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#3
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Site Team
Join Date: Aug 2007
Location: Omaha
Posts: 6,796
M.O.C. #7560
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Dan-- It could be the auto breaker is getting weak and causing it to overheat upon retraction. It will cause that problem IF it is weak. You might want to try and change the auto breaker if you know where it is and see if that helps any! I've heard of this causing the problem you've discribed but it doesn't happen all the time. Check it out and keep us informed on the situation and what you come up with!
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05-06-2010, 09:56 AM
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#4
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Montana Master
Join Date: Feb 2005
Location: Haysville
Posts: 4,261
M.O.C. #3085
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Unless the pumps have changed in the past couple of years ... there are no "valves" per say to direct the flow of fluid. Our pumps run in both directions to get the desired direction of travel. There is a "trombetta" electric solenoid on the top of the pump ... it, in conjunction with the wall switch, controls the direction of the pump motor and thus the direction of the slides. Perhaps your trombetta is faulty if you just have problems in one direction. The manifold with the manual slide controls are just shutoff valves ... you close the valve to the slide you don't want to operate. It's either something along these lines or ... seal issues as stated earlier.
On Edit ... a long shot would be the impeller in the pump is spinning on the motor shaft in the retract direction, but not in the extend direction ... I'm just throwing this out there as I cannot imagine the impeller loose in just one direction.
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05-06-2010, 12:48 PM
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#5
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Seasoned Camper
Join Date: Jul 2007
Location:
Posts: 62
M.O.C. #7362
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Dan, had a similar problem with the electric steps. They would go out but not back in . Turned out to be the double pole/double throw switch as Jerry suggested. Got one at CW and it fixed the problem. Not sure if your slides are wired with such a switch but if so it might be worth your time to check the switch if nothing else seems to solve your problem, Best wishes, Jay and Kathy
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05-11-2010, 10:20 AM
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#6
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Seasoned Camper
Join Date: Feb 2010
Location: Sterling
Posts: 85
M.O.C. #10132
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I'm just back to internet service - I was away for a few days or I would have been in this conversation better.
Thanks for your posts on about my slide problem. This is very helpful. I didn't understand that there are no actual valves that change the direction of hydraulic fluid. This thought brings more clarity to the problem. It can't be too expensive to simply start changing out components starting with the control switch (just to be sure) and if that doesn't work then the trombetta selonoid(s) to see if that solves the problem.
Since I can hear the electric motor running (when the slides don't retract)I think I can rule out the outo circuit breaker as the problem.
I'll order parts and hope for the best. Thanks again for your help.
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05-11-2010, 10:58 AM
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#7
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Montana Master
Join Date: Dec 2006
Location:
Posts: 2,376
M.O.C. #6575
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If you hear the motor running when the slides won't retract, I don't think the problem is electrical. Either a hydraulics problem, or something is binding on the slide. The hydraulic rams put out less force when bringing in the slides, due to loss of surface area on the piston where the rod attaches. Hard to diagnose problems like that without seeing it in action.
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05-11-2010, 05:50 PM
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#8
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Seasoned Camper
Join Date: Feb 2010
Location: Sterling
Posts: 85
M.O.C. #10132
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SlickWillie - I'm thinking that when the switch is depressed it does two things. One, it actuates the selonoid that starts the electric motor (which is working fine) and, two it sets the direction of the impellers of the pump to coincide with either "extend" or "retract". That's where I'm thinking one possible problem is. Either the contact on the switch isn't working properly to signal the impeller direction correctly, or the trombetta selonoid isn't reacting to the signal. There's no indication that the room is stuck or binding. Sometimes the "retract" works properly after 2 or 3 tries on the switch. When it works it really works well. Sometimes it stutters - starts in, kicks back out a couple of inches, and then retracts properly. Like the impellers switch back and forth momentarily.
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05-12-2010, 02:04 AM
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#9
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Montana Master
Join Date: Dec 2006
Location:
Posts: 2,376
M.O.C. #6575
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Lippert PDF There is a diagram of the slide hydraulic system. You may also have a valve block to control which slide/s go out. The solenoids merely change the battery leads to the pump and thus change rotation to change inlet/outlet on the pump.
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05-12-2010, 07:40 AM
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#10
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Seasoned Camper
Join Date: Feb 2010
Location: Sterling
Posts: 85
M.O.C. #10132
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SlickWillie - this is very helpful - thanks. I'm getting zeroed in a little more after looking at the Lippert manual (Duh, I shudda went there first). My Montana is an '02 so its more archiac than what is shown in the manual. Looks like the same overall design but a much older version with some slightly different components that have probably been improved upon over the years. I'll have to contact Lippert for the older manual and some technical assistance after getting the model information from the unit (right now it's down in Sterling, AK about 4 hours away). As soon as I can get free from some other duties I'll get back to Sterling and into solutions for this. Again...many thanks for your valuable info. ...dan
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05-12-2010, 07:44 AM
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#11
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Montana Master
Join Date: Dec 2006
Location:
Posts: 2,376
M.O.C. #6575
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Quote:
quote:Originally posted by danandbetty
SlickWillie - this is very helpful - thanks. I'm getting zeroed in a little more after looking at the Lippert manual (Duh, I shudda went there first). My Montana is an '02 so its more archiac than what is shown in the manual. Looks like the same overall design but a much older version with some slightly different components that have probably been improved upon over the years. I'll have to contact Lippert for the older manual and some technical assistance after getting the model information from the unit (right now it's down in Sterling, AK about 4 hours away). As soon as I can get free from some other duties I'll get back to Sterling and into solutions for this. Again...many thanks for your valuable info. ...dan
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Dang, I didn't think about that. Seems they changed pumps in 2003 or so. Good luck on it.
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05-20-2010, 11:21 AM
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#12
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Seasoned Camper
Join Date: Feb 2010
Location: Sterling
Posts: 85
M.O.C. #10132
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UPDATE - I just ordered a new motor/pump/reservoir assembly for my old '02 hydraulic slide system. Due to it's age many parts are no longer available for the old "1st generation" unidirectional motor/pump system so I've had to upgrade the whole thing to current technology. $1200 total.
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05-20-2010, 12:15 PM
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#13
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Montana Master
Join Date: Dec 2006
Location:
Posts: 2,376
M.O.C. #6575
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Ouch! Glad you're getting it fixed though. Good luck.
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05-20-2010, 07:06 PM
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#14
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Montana Master
Join Date: Jun 2004
Location: Mount Shasta
Posts: 1,488
M.O.C. #1685
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Dan,
Sorry I didn't see your original post earlier. I've sent you an e-mail regarding the early Montana slide out system. I have the parts and service manual as well as the trouble shooting guide or you can find the info online at www.powergearus.com.
Perhaps you'll find an answer here and can get a refund on that order?
Don
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05-26-2010, 09:12 AM
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#15
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Seasoned Camper
Join Date: Feb 2010
Location: Sterling
Posts: 85
M.O.C. #10132
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Don, thanks for the info. Mine is a Lippert system and the solenoid cartridge valves I need were manufactured by Hydraforce who no longer makes the ones I need.
I think some of the older models have Dewald systems and possibly some have other brands as well. Is the manual you have one that covers the Lippert system? If so I'd be plenty interested. Otherwise i suspect it won't help. Thanks so much in any case. dan
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