Slide-Out Hydraulic Service for ENTEGRA ASPIRE
This comprehensive guide will walk you through repairing slide-out hydraulic service on your ENTEGRA ASPIRE. Follow each step carefully and gather all required parts before beginning.
Required Parts
- Dexron VI ATF – 2-3 quarts
- Hydraulic pump motor
- Cylinder seals
Step-by-Step Instructions
Step 1: Hydraulic Slide-Out System Overview
The Newmar Dutch Star typically features multiple large slide-out rooms (often 3-4 slides) that significantly expand the interior living space when parked. These slide-outs use a hydraulic system rather than electric motors (common in smaller RVs) because hydraulics provide the substantial force necessary to move these heavy rooms, which can weigh 1,500-3,000 pounds each when fully furnished. The hydraulic system consists of a 12-volt electric motor driving a hydraulic pump assembly, a reservoir holding hydraulic fluid (typically 1-2 quarts), a manifold with solenoid valves that direct fluid to specific cylinders, hydraulic cylinders (usually two per slide-out for even extension/retraction), high-pressure hydraulic lines connecting all components, and a control panel inside the coach that activates individual slides. Understanding this system is important because unlike simple electric slides, hydraulic systems require regular fluid maintenance, seal inspection, and pressure testing. Common symptoms of hydraulic system problems include slow or uneven slide-out movement, one slide working while others don’t, fluid leaks visible underneath the coach or inside compartments, or complete system failure where no slides operate.
Step 2: Safety Preparation and Initial System Assessment
Before performing any hydraulic system service on slide-outs, the motorhome must be parked on level ground with adequate space around all slides. This is critical – operating slides on unlevel ground causes binding, uneven load distribution, and premature seal wear. Use a bubble level to verify the coach is level side-to-side and front-to-rear. If not level, use the automatic leveling jacks to level the coach before proceeding. Ensure all slides are fully retracted or fully extended (not partially extended) before working on the system – partially extended slides carry hydraulic pressure and moving components that can cause injury. Disconnect shore power or turn off the generator to ensure the slide-out system cannot be accidentally activated while you’re working underneath or around the slide mechanisms. Chock all wheels securely. Locate the hydraulic pump assembly, which is typically mounted in a basement compartment or in the engine bay area – consult your coach’s manual for exact location. The pump assembly will have multiple hydraulic lines connected to it (one pair for each slide-out), electrical connections, and a reservoir with a fill cap.
Step 3: Fluid Level Check and Condition Assessment
Locate the hydraulic reservoir on the pump assembly – it’s typically a clear or translucent plastic reservoir with “FULL” and “ADD” level marks, or it may have a dipstick. With all slide-outs fully retracted (which returns all hydraulic fluid to the reservoir), check the fluid level. The fluid should be at or near the “FULL” mark. Low fluid is the most common cause of hydraulic slide-out problems and indicates either a leak or seals that have worn and are allowing fluid to bypass. Examine the fluid condition by looking at it against a white background or drawing a sample into a clear container. Healthy hydraulic fluid should be clear to light amber colored with a slightly oily consistency. Dark brown or black fluid indicates oxidation and contamination requiring a complete fluid change. Milky or cloudy fluid indicates water contamination, which is extremely detrimental to hydraulic components and requires immediate attention. The presence of metal particles, glitter, or debris indicates internal component wear or damage. If fluid is at proper level but severely contaminated, plan to drain and replace all fluid in the system.
Step 4: Hydraulic Line and Connection Inspection
With the motorhome on jack stands for safety (never work under an RV supported only on leveling jacks), crawl underneath and perform a comprehensive visual inspection of all hydraulic lines and connections. Hydraulic slide-out systems on the Dutch Star typically use 1/4″ or 3/8″ high-pressure steel braided or nylon-reinforced rubber hoses running from the pump assembly through the frame rails to each slide-out cylinder. Inspect every inch of these lines for abrasion (especially where lines pass through frame holes or contact other components), kinks, cracks in the outer jacket, swelling or soft spots (indicates internal breakdown), or obvious fluid seepage. Check all threaded connections and fittings for tightness and signs of leakage – hydraulic fluid weeping from fittings creates an oily residue that attracts dirt. Pay particular attention to where lines connect to the cylinders at each slide-out – these connections experience significant flexing during slide operation and are prone to loosening or developing leaks. Use flare nut wrenches (not standard wrenches) to carefully snug any loose fittings – these specialized wrenches prevent rounding off the soft brass or aluminum fittings. If you find damaged hydraulic lines, they must be replaced immediately as burst hydraulic lines can cause complete system failure and leave slides in dangerous positions.
Step 5: Cylinder Seal Inspection and Minor Leak Repair
Each hydraulic cylinder on the slide-outs has seals (o-rings and backup rings) that prevent fluid from leaking past the cylinder rod. Over time, these seals dry out, crack, or wear, causing fluid to leak from the cylinder shaft area. Inspect each cylinder carefully by operating each slide-out individually while observing the cylinders. With someone at the control panel inside the coach, extend each slide slowly while you watch the cylinders from underneath or from inside the slide cavity. Look for hydraulic fluid weeping or dripping from the rod where it extends from the cylinder body – a small amount of oil film on the rod is normal (it provides lubrication), but dripping or running fluid indicates failed seals. If seals are leaking on one or more cylinders, they can often be replaced without removing the entire cylinder from the slide-out. To replace seals: fully retract the affected slide, disconnect the hydraulic lines from that cylinder (have rags ready to catch fluid), remove the mounting bolts securing the cylinder, carefully extract the cylinder from the slide mechanism, disassemble the cylinder following the manufacturer’s instructions, replace all seals with new ones from a rebuild kit, reassemble with proper lubrication on all seals, and reinstall the cylinder. This is an advanced repair that requires mechanical aptitude and careful attention to cleanliness – any dirt introduced during seal replacement will damage the new seals immediately.
Step 6: Pump Motor and Solenoid Testing
If all slides fail to operate or operate very slowly despite adequate fluid levels and no visible leaks, the problem is likely the hydraulic pump motor or solenoids. To test the pump motor: Have someone inside the coach activate any slide-out switch while you listen at the pump assembly. You should hear the electric motor running and the pump producing a distinct pumping sound (often described as a whirring or humming). If you hear the motor running but no pumping sound, the pump coupling may have failed, or the pump may be seized. If there’s complete silence, test for 12V power at the pump motor terminals using a multimeter – if voltage is present but the motor doesn’t run, the motor has failed and requires replacement. To test solenoids: With the motor running, use a multimeter to check for 12V at each solenoid when its corresponding slide switch is activated. The solenoid should click audibly when energized. If the solenoid has power but doesn’t click, or clicks but the slide doesn’t move, that solenoid has failed. Solenoid replacement is straightforward: disconnect hydraulic lines (catch fluid), disconnect electrical wires, unscrew the old solenoid from the manifold, install a new solenoid with thread sealant on the threads, reconnect everything, and refill/bleed the system.
Step 7: Fluid Replacement and System Bleeding
If your fluid condition assessment in Step 3 revealed contaminated fluid, or if it’s been 3+ years since a fluid change, perform a complete fluid replacement. Start by fully retracting all slide-outs to return all fluid to the reservoir. Remove the reservoir fill cap and use a fluid transfer pump or turkey baster to remove as much old fluid as possible from the reservoir. Locate drain points on the hydraulic system (there may be bleeder screws on the manifold or cylinders, or you might need to disconnect the lowest hydraulic line) and drain all old fluid into a collection pan – expect 1.5-2 quarts total system capacity. Once drained, reconnect all drain points. Fill the reservoir with fresh Dexron VI ATF to the “FULL” mark. Now you must bleed air from the system: Operate each slide-out slowly, extending it about 6 inches, then retracting it fully. This pushes fresh fluid through that slide’s circuit and purges air. Check the reservoir after each slide operation and top off as needed – extending slides pulls fluid from the reservoir. Repeat this process 2-3 times for each slide until operation is smooth and consistent without jerking or hesitation. Final fluid level should be at “FULL” with all slides retracted. Test all slides through several complete extension/retraction cycles, checking for leaks at all fittings and connections. Clean up any spilled hydraulic fluid immediately as it’s slippery and attracts dirt.