Crown air filter change - HOW??

[Tejon7]

Changing an air filter should be about the easiest maintenance item on a bus, but I'm embarrassingly stumped by this. Here's a picture of the filter compartment on the driver's side of the bus, just behind the engine:


There are four main parts here: the filter box on the left, the box cover that I'm holding on the right, a bottom plate that I had already removed for this picture, and the filter element itself (still inside the box in this pic).

From the picture, it looks like I should be able to easily pull the box cover out of the bus, swap out the filter elements, then reassemble. What you don't see in the pic is a drain vent of some kind that sticks down from the box cover several inches and makes it so that no matter how I try, I cannot get that damned cover out of the bus! I wrestled with that thing for 1/2 hour with no luck. Fortunately, I was able to inspect the old filter with a camera and it looks fine for now, but someday I'll need to change it.

FYI, the three bolts/nuts on the left of the pic have not been removed since it left the factory, yet the filter was supposedly replaced in 2020. Those and their extremely hard-to-reach cousins on the back of the filter box will be my last resort, but I'm thinking there has to be a better way.

Crown experts, what's the trick here? Everything else on this bus is well thought-out and relatively easy to access, so I must be missing something!

[rossvtaylor]

Well, that's odd. I've never seen that orientation of the filter box. On mine, and on ones I've changed for others, the opening of the filter housing faces the opening of the door...so you just pull it straight out. I'm afraid I've not seen one mounted sideways like that.

[flattracker]

Since I have the same setup in both of my Crowns and have had the air filter replaced in the "old Crown", I will ask my old race buddy tomorrow, as he worked on both of my Crowns. Edwards Truck in Salinas Ca. did the work.

[Tejon7]

The box facing outwards would be so much simpler. Wish mine was that way!! Strange that they changed it up... Could it have been a turbo vs naturally aspirated thing?

Any advice you can dig up would be much appreciated Flattracker. I'm glad to hear that your buses have the same setup. At least mine isn't too much of an oddity!

[rossvtaylor]

Originally Posted by Tejon7

Could it have been a turbo vs naturally aspirated thing?

That could be. The mid-engine Crowns I've worked on were NA 6-71 engines.

[bus-bro]

I saw a bunch of turbo'd 671 mid-engine Crowns going through auction about 10 to 15 years ago. They were the 10 wheelers.

You're doing your filter changeout wrong, evidenced by its difficulty. I'd say you'd pull the filer element out the same direction you pulled the cover off.

[Tejon7]

Agreed, the filter needs to come out the same way as the cover. The problem is that the cover is in the way. The picture makes it look like cover should slide out easily, but after 30 minutes of trying different orientations, I was still unable to pull that damned cover out of the compartment. There must be a simple trick I'm missing here.