What's going on here?

[DiddBiddy]

So I think I've located where the water was getting into my bus (picture below)... and the rust damage that it caused leaves me with a couple of questions.

First it appears that this area of the bus was previously worked on because the hat-channels have been cut out and replaced with "c" channels (from the outside you can see where the new "c's" overlap and are welded into existing channels just above lower window line) but the water intrusion wasn't solved obviously because on both sides the final three "c" channels behind these interior panels are completely rusted... or this was just the factory engineering?? I can't tell, as my searches have yielded no information anywhere on what the purpose of these double decker paneling sections are...

My best guess is they are additional support structure for the engine and/or for the bus in case of side collision behind the rear wheels but in any case... I need to (A.) either completely replace these rusted channels or (B.) gain enough access to flap disc to good metal or rust convert and paint.

I could be completely wrong here but are the only options to remove rivets and exterior skin to gain access, or can I cut out these additional interior side panels to gain access? It seems to me that if I do the latter I would need to replace these panels since they must serve some purpose... haha I'm at a loss

Either way it looks like a ton of work that is absolutely necessary.

Any ideas or suggestions?

[DeMac]

I see IC Chassis. What model & make of bus?

Our IC RE has several steel plates, channels and angle stock supports in the walls. The body steel is two layers of grey 16g steel, above all four of the wheel wells. The bulk of the thick, black steel is in the walls under the last few windows.










I always guessed the black steel is there to support the load and twisting forces of the RE. The grey double layer over the wells, as there is material missing and no floor-to-wall joint. Like a door or window header, in buildings. Idk, I'm just a guesser.

[DiddBiddy]

Originally Posted by DeMac

Is yours a Crown by Carpenter?
I see IC Chassis. What model & make of bus?

2000 International AmTran passenger bus

[DeMac]

The structural design & shape of the additional steel, looks to be the same as mine. The differences in our pictures seem to be the natural manufacturing progress durring the nine years between our model years.

To me, it looks as though it was done at the factory, when it was being built, not a repair job.

Do you have intake vent(s) in the rear side(s)? Those absolutely channel water forward, on pre-'07 models. Might be the souce of the moisture.

[musigenesis]

Originally Posted by DeMac

The grey double layer over the wells, as there is material missing and no floor-to-wall joint. Like a door or window header, in buildings. Idk, I'm just a guesser.

My bus also has extra reinforcing material between the ribs above the wheel wells. My guess is also that this is to compensate for the large cutout in the chair rail beam that is needed to accommodate the wheel wells. Every place in my bus where the chair rail is "broken" in some way (wheel wells, the side exit door, and the cutout for the fuel pipe) there is extra structure to compensate for this.

OP, what you've posted looks kinda homegrown, though, something that seems to happen from time to time with buses in long service. My bus, for example, had a rib replaced at some point in its past with additional cross-member support welded to the underside.

You should be able to access all of this from the inside by cutting the rest of the interior panels off (but not the chair rail at the bottom!). The interior side panels don't do anything but prevent the kids from eating the insulation (I think that's all the ceiling panels do as well but that's more controversial).

[musigenesis]

BTW that rust damage is almost certainly due to the windows leaking - very, very common in school buses.

[DiddBiddy]

Originally Posted by DeMac

To me, it looks as though it was done at the factory, when it was being built, not a repair job.

Do you have intake vent(s) in the rear side(s)? Those absolutely channel water forward, on pre-'07 models. Might be the souce of the moisture.

That would honestly make sense it being factory engineering because I couldn't find anything specific to hat channel repair/replacement work in the maintenance log from the school district it was purchased through...


Yep! it used to have the air intake vents that allowed daylight in between where the panels met the outer skin.


Starting to sound like perhaps the best and only course of action is to gain access through the exterior skin...

[DiddBiddy]

Originally Posted by musigenesis

My bus also has extra reinforcing material between the ribs above the wheel wells. My guess is also that this is to compensate for the large cutout in the chair rail beam that is needed to accommodate the wheel wells. Every place in my bus where the chair rail is "broken" in some way (wheel wells, the side exit door, and the cutout for the fuel pipe) there is extra structure to compensate for this.

OP, what you've posted looks kinda homegrown, though, something that seems to happen from time to time with buses in long service. My bus, for example, had a rib replaced at some point in its past with additional cross-member support welded to the underside.

You should be able to access all of this from the inside by cutting the rest of the interior panels off (but not the chair rail at the bottom!). The interior side panels don't do anything but prevent the kids from eating the insulation (I think that's all the ceiling panels do as well but that's more controversial).

ahhh okay... yeah based off the photo (below) I've been going back and forth but leaning towards repair work but was unduly giving the benefit of the doubt thinking "Shirley" they would have attempted to address any water led corrosion issues lol...

DeMAC and musigenesis! Cutting out those panels to address the issue sure sounds like a much easier approach. Now my concern turns to the rust along the chair rails behind the interior portion of the engine bay panels... you got to do what you got to do though right