HWH Slide Seal Replacement

Our bedroom slide air seal / bladder developed a sudden and substantial leak on 9/2/10, you could hear the leak from inside the coach and the HWH Aux pump was running non-stop trying to keep up. Going outside it was easy to locate the leak, the bladder had a approx 1” tear along a top “seam” right inside the lower U channel.

We tried a variety of things to seal the tear (patches, tape, glues) but no luck. Some things held for a short while but in the end the tear continued to propagate past the patch and begin to leak. The bladders are not as tough as a tire sidewall to resist tear propagation.

Some have reported good luck using Aquaseal in sealing tears. For us once the tear extended past the U channel it was essentially inaccessible to try additional “patch” items.

Manifold Valves

As luck would have it, shutting off the air supply to the bladder resulted in that shutoff valve leaking. So another trip to the store to buy some new ball valves to replace them. We ended up purchasing a couple of compact 1/4” valves that were with the air tools.

In our coach the bedroom slide is #2 and the living room side is #1 on the manifolds.

Missing Parts

Shelf properly installed / Missing Shelf

The cause of this leak was determined to be a assembly error back from when the coach was manufactured. There should be a “shelf” below the U channel for the bladder to push against. The shelf prevents the bladder from ballooning into the channel and over stretching the material. Our front slide had the shelf, the rear one did not. When the bladder was replaced, the missing shelf was found, lying on the floor inside the slide, someone simply forgot to install it.


We had the slide bladder replaced at MOT. To do this they detach the mechanism from the slide mounting points. This allows the entire slide to tilt inward, providing access to the bladder. Some earlier coaches have to have the slide entirely removed.

Once you gain access you can begin the process of removing the old bladder. Its held in place first by a (2) seal retainers and secondly by double sided 3M VHB tape. After you get the bladder out, you have the fun process of removing all of the VHB tape that stays behind in the aluminum channels. That is a slow process.

Once its all out, and the channels cleaned up, you reverse the process. Adhere new VHB tape in the channels, place the bladders in place, remove the upper tape liner, adhering the rubber bladders to the channel. Finish it off my reinstalling the mechanical seal retainers.


Here are two short video clips of the slide seals inflating / deflating as seen from the inside of the coach.