BCM Community

Hi All,

Successfully replaced mufflers on my bus last week.  Ended up not being a bad job other than looking like a Welsh coalminer after!!  Decided to gut the flooring in the old gal because already halfway there due to removing bed to get at mufflers through inspection panel.

During the floor removal process found a lot of moisture on floor edges under the back of each window.  Removed everything down to the original treated plywood which is in good shape.  Any suggestions on how to deal with the moisture problems?  I don't want to seal the windows as we drive with them partially open in summer and like fresh air when parked.

Any advice would be appreciated.

Aron.

 :D

Aron,

Did you use stock mufflers for replacements? I changed my setup so I could use much smaller ones, sure helped getting through that small hole and were much lighter.

I still have all my original windows and like them except it would be nice to have double panes. Most 4104 window gaskets are long gone and probably cause most of the leaks. I've replaced the vertical gaskets which "wipe" the window when opened and closed but not the others yet. The others are really dried out.

Mine leaks quite a bit also but a bunch of my windows have been sealed with silicone seal by the PO and I am stuck with them as is. It is impossible to get to the silicone to cut it. Unfortunately the leaks weren't where the silicone was used.

Since you are at the gutting stage you can probably replace all your window gaskets and stop the leaks. I bought mine converted and didn't have that luxery.

If you find the answer let us know.

Replacing the floor is a huge job. Let us know how that turns out.

The   4104 is a great machine.

Hi Gus,

Got the muffler through Luke at US Coach.  It's stock and yes very big and a little awkward but manageable.  I replaced one and patched the other.  Just cut a patch out of one of the old ones and welded it on the salvageable one. 

The floor replacement has been going good and I finished rebuilding the bedroom in the back today.

I'll let you know how the rest goes as I progress.

I agree with you, the 4104 is a great machine.  I've driven it as far south as Puerto Valllarta and all over the States

Cheers.

Aron.

Aron,

Keep a close watch on that muffler you patched. There have been a few 4104s burn because a leak here shoots fire straight up into the bedroom floor.

The OEM mufflers tend to fail on top because of the ridge that traps moisture and dirt which results in much rust. I first changed only one then found the other one was failing just below the manifold clamp. It was hard to see even when I was replacing the other one.

I bought two smaller mufflers from JCW that had smooth tops so nothing could stick there. I had to weld on a couple of short pipes and new flanges to the mufflers to connect to the engine exhaust manifold, but overall I think they are superior to the originals and I can't tell any difference in the sound.

I'll be glad to email you the diagram I made of the mod.

Hi Gus,

I had the patch welded at a local metal fabrication shop.  The rest of the muffler was sound and the patch I cut was full lenth so the welds should be in strong points.  It is a bit of a design flaw to have so much catchment area on top of the cans for moisture.  Not good long run.

I would really appreciate any diagrams and such that you have if I ever have to do this again.  I'll PM you with my e-mail address.

Cheers.

Aron.

Muffler stuff is on the way.

Thank-you sir!