Experiencing water intrusion at the base of my slide out on a 2023 Forest River Forester MBS2401B. The leak occurs specifically when the slide is in the retracted position during wind-driven rain events. Water is penetrating at floor level beneath the dinette area of the full wall slide assembly.
I have verified that all visible seals appear to be properly seated and the topper awning shows no obvious damage. Given that this is occurring on a current model year unit, I need to understand if this represents a manufacturing defect covered under warranty, and what specific component is likely causing the failure at the bottom of the slide mechanism.
Slide bottom leaks when retracted are from bottom wiper seal not making proper contact. On a 2023 unit, this is warranty work. Document with photos and contact your dealer.
Your 2023 Forest River Forester MBS2401B has a classic slide floor seal failure that's letting wind-driven rain penetrate under the dinette area. Since you've already verified the vertical seals are properly seated and the topper awning looks good, the issue is almost certainly with the bottom wiper seal or the slide floor's weatherstripping system. This is a common problem on full-wall slides like yours, especially during the first few years when seals are still settling and adjusting to expansion/contraction cycles.
The fact that water only comes in during wind-blown rain tells us the seal isn't completely failed - it's just not tight enough to handle pressure-driven moisture. Your slide mechanism is working properly since you can cycle it in and out, so we're dealing with a sealing issue rather than an alignment problem.
Forest River uses a combination of wiper seals and bulb seals on the bottom of their slide systems, and these are particularly vulnerable on full-wall slides due to the weight and span involved. The bottom seal has to compress properly against the slide floor when retracted, but several factors can prevent this from happening effectively.
Temperature changes cause the slide box and coach frame to expand and contract at different rates, which can create gaps in the seal over time. Additionally, the slide adjustment may have shifted slightly since delivery - even a few millimeters can create enough gap for wind-driven rain to penetrate. Road vibration and settling of the coach can also affect how well the bottom seal mates with the slide floor.
The 2023 model year also saw some changes in Forest River's sealing systems, and some early production units had issues with seal compression that weren't immediately apparent during dry weather testing. Wind-blown rain creates much more pressure than normal precipitation, which exposes these marginal seal conditions.
SAFETY WARNING: Before beginning any slide repair work, disconnect power to the slide system at the main panel and engage the slide lockout mechanism if equipped (not all Forest River models include this feature - verify in your owner's manual). Ensure the slide is properly supported and cannot move unexpectedly during inspection or repair work.
You'll need a good LED flashlight or headlamp for inspection, a putty knife or plastic trim tool, marine-grade silicone sealant, and potentially some foam backer rod. Have some rags and denatured alcohol on hand for cleaning surfaces. A small mirror can help you see the seal areas better when the slide is retracted.
Plan to do this work on a dry day when you can extend and retract the slide multiple times. You'll want to inspect both the seal itself and the surface it seals against. Take photos of the seal configuration before making any changes - this will help if you need to order replacement parts or consult with Forest River.
Check your owner's manual for the specific slide manufacturer - Check your owner's manual or contact your dealer to verify which slide system manufacturer (commonly Lippert or Schwintek) was used on your specific unit. Knowing the manufacturer will help you identify the correct part for your model (verify with dealer) if needed. Also verify your warranty status since this is a 2023 unit.
Start by extending the slide completely and properly supporting it with manufacturer-approved slide supports or jack stands before examining the bottom wiper seal from underneath. Look for tears, compression set (permanent flattening), or areas where the seal has pulled away from its mounting track. The seal should have a consistent bulb shape along its entire length when not compressed.
With the slide extended, clean the seal and the slide floor surface it contacts with denatured alcohol. Remove any dirt, old sealant, or debris. Retract the slide slowly while watching how the seal compresses - it should make consistent contact across the entire width. Mark any areas where you see gaps or poor compression.
If the seal looks good but isn't compressing properly, the slide may need minor adjustment. Check the slide adjustment bolts (usually accessible from inside the coach) - however, making adjustments may void your warranty on a 2023 unit. Consult your dealer first for specific adjustment procedures and torque specifications, as improper adjustment can cause damage. Test the seal compression after each adjustment.
For seal gaps that can't be fixed with adjustment, apply marine-grade silicone sealant to create additional sealing. Clean the area thoroughly, apply painter's tape to keep lines neat, and use a thin bead of sealant where the seal contacts the floor. Smooth with your finger and remove tape while the sealant is still wet.
If the bottom seal is damaged, you'll need to remove the old seal from its mounting track and install a replacement. Forest River typically uses a bulb seal that slides into a U-channel track. Measure the seal dimensions carefully and order the correct replacement part from Lippert or your Forest River dealer.
If adjusting the slide and resealing doesn't solve the problem, you may have a structural issue with the slide box or coach frame that's preventing proper seal compression. This requires professional diagnosis with proper measuring tools and potentially involves warranty work since your unit is so new.
Complex slide adjustments that involve the drive mechanism or support arms should be left to certified technicians. Improper adjustment can cause binding, motor damage, or create new leak points. If your slide has been in an accident or shows signs of frame damage, professional inspection is essential.
Water damage remediation should also be handled professionally if you discover moisture has penetrated into wall cavities or flooring systems. What starts as a simple seal leak can become a major structural issue if water reaches wooden components or insulation. Given that this is a 2023 unit, document everything thoroughly and contact Forest River's customer service if the problem persists after your repair attempts.
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