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Author Topic: How do the hydraulic slide rams work  (Read 959 times)

Steve Zannella

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How do the hydraulic slide rams work
« on: March 13, 2019, 11:59:51 PM »
On my 2004 marquis I have 2 front slides and a leaking hose fitting at the pump manifold. I don't know which slide in or out hose is leaking. I can't follow the hose as it disappears into the chassis. How can I determine which slide and which function in or out it performs.
2004 Beaver Marquis Garnet
Steve Zannella

Gerald Farris

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Re: How do the hydraulic slide rams work
« Reply #1 on: March 14, 2019, 12:23:20 AM »
Steve,
There are two hoses to each slide cylinder, and one hose is pressurized under extension and one is pressurized under retraction with the corresponding hose being vented to the fluid return in the fluid reservoir when either hose is pressurized for movement. Since the hydraulic hose will move when it is under full pressure, you can determine which hose is leaking by just moving the slide, and watching or feeling the hose, but be careful as a pin hole in a hose at 3,000 PSI can penetrate the skin.

The other way to determine if it is the extension or retraction hose if you know which slide it is going to is to slightly loosen the hose, since the extension hose will have residual  pressure when the slide is extended and the retraction hose will have pressure when the slide is retracted.

Gerald
2002 Solitaire (2017 -  )
2000 Marquis, C12 (2004 - 2017)
1993 Patriot  (2000-2004)
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Steve Zannella

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Re: How do the hydraulic slide rams work
« Reply #2 on: March 14, 2019, 01:22:30 AM »
Thanks Gerald
Can I assume that the "slide in" hose is on the piston shaft or slide extension side and the "slide out" hose connection is on the cylinder bottom or reverse side of the piston shaft end.
2004 Beaver Marquis Garnet
Steve Zannella

Mike Shumack

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Re: How do the hydraulic slide rams work
« Reply #3 on: March 14, 2019, 11:13:34 AM »
Is this the HWH pump/manifold setup? If so, you could unplug the solenoids one pair at a time (or use the pressure release screw/cam) then try to operate the slide. That would tell you which solenoid group and hose is for which slide.

HWH has this publication for identifying the which solenoids are for what rooms but the publication also warns that coach builders may not have followed the HWH guidelines and to unplug the solenoids to confirm.

Are you going to be replacing the hose (I assume you tried to tighten the fitting)?
- Mike

'05 Beaver Patriot Thunder, Vicksburg, CAT C13  525HP, Allison 4000MH, HydraLift

Gerald Farris

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Re: How do the hydraulic slide rams work
« Reply #4 on: March 14, 2019, 04:25:13 PM »
Steve,
Yes, the extend hose is attached near the base of the cylinder, and the retract hose is attached near the shaft end of the cylinder.

Gerald
2002 Solitaire (2017 -  )
2000 Marquis, C12 (2004 - 2017)
1993 Patriot  (2000-2004)

Steve Zannella

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Re: How do the hydraulic slide rams work
« Reply #5 on: March 15, 2019, 05:36:58 PM »
Gerald
That is what I expected it's my slide out hose crimp that's leaking at the pump manifold. I can't see the hose connection as the barrel extends into the frame and is blocked from access by the metal covering around the fresh water tank. I guess all the covering must come off to access the fitting. I would have wished it was the slide in line as it's easy to access.

Another thought rather than replacing the hose, which appears OK, could a barbed flair fitting with clamps be used on the hose or is the pressure too great.

Thanks again Steve
2004 Beaver Marquis Garnet
Steve Zannella

Gerald Farris

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Re: How do the hydraulic slide rams work
« Reply #6 on: March 15, 2019, 06:06:20 PM »
Steve,
The pressure is too high in that hose for a clamp and hose barb, but if there is room, a good hydraulic shop can replace the crimped fitting after cutting a few inches off of the hose with a portable crimper. However, I have never seen that much extra length or working space on a Beaver coach at the pump solenoid manifold. If you remove the shielding and insulation around your water tank, be sure to reinstall it properly to prevent tank damage in cold weather.

Gerald
2002 Solitaire (2017 -  )
2000 Marquis, C12 (2004 - 2017)
1993 Patriot  (2000-2004)