LANCE 1985 – Slide-Out Seal Replacement

RV repairs are either thirty minutes or three days — there’s rarely an in-between. The difference is almost always whether you understand the system before you start, whether you have the right tools, and whether you ordered the correct part the first time. I’ve learned all three lessons the hard way, multiple times. On the Lance 1985, the slide-out seal is one of those repairs that looks like a straightforward afternoon job right up until water has been quietly wicking past a cracked or compressed wiper seal for two seasons and you’re suddenly staring at soft floor decking and delaminating sidewalls — problems that turn a $60 fix into a $3,000 headache. I’ve walked this exact repair on enough older Lance units to know where the shortcuts blow up on you, which seal profiles actually fit the Lance’s slide box tolerances, and what worn hardware to replace while you’ve already got everything pulled apart.

The Combo Seal Kit That Stops Water From Rotting Your Lance From the Inside Out

On a 1985 Lance, the slide-out seal fails in two places at once — the wiper seal compresses and cracks, and the base seal hardens and separates from the aluminum frame. You need both pieces, not just one, or water finds the gap and you’re looking at soft walls and mold behind cabinetry within a season.

What works

• Both the 018-341 EK and 018-312-EKD seals ship together, so you’re not making a second order halfway through the repair when you realize the first piece alone didn’t stop the leaks.
• The 35-foot lengths give you enough material to replace the full perimeter of a Lance slide-out and still have 8-10 feet left for patches or future repairs on trim elsewhere.
• Once seated properly, the dual-seal design creates a real barrier — you’ll notice the slide-out moves smoother, feels tighter, and condensation stops pooling on the floor after a cold night.

What doesn’t

• Both seals require adhesive backing or contact cement to stay put on aluminum that’s been sitting in the sun for 40 years — the old glue residue doesn’t just come off with a scraper, and insufficient prep means the seal creeps back within weeks.
• Finding the exact mounting groove on the Lance frame takes trial fit-and-adjust; the seals are slightly oversized by design, so you’ll be trimming and re-seating multiple times before you get it right.

I second-guessed whether 35 feet was actually enough coverage until I ran the numbers and realized I’d overestimated the perimeter by nearly 40 percent — don’t repeat that mistake, and measure your actual slide-out frame before ordering. Grab the 018-341 EK Slide Out Rubber Seal & 018-312-EKD RV Weather Stripping Exterior for RV Camper, 1′ x 15/16′ x 35′ and 1/2′ x 2.75′ x 35′ Combo Slideout Wiper Seal and get both seals done in one job.

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