Wheel Wells & Air Beams

[Stan]

NCBob: Your MC5A is approaching 50 years old and if the air beams are still good it shoots down the theory that all air beams rust and leak.

I don't agree with your theory on axle movement causing air movement in the bag. The axle should not rotate unless the radius rod bushings are worn. The better ride is simply a matter of having a larger volume of air in the system than if the beams are sealed off.

[kyle4501]

Hey Stan, one of my PD4501's is a 1956 & the air beams still hold air. I can find no significant rust anywhere in the structure. It was a west coast bus.

My 1954 has rust holes in the air beams large enough to stick a couple of fingers in. Yes those bags have block-off plates. this was an Eastern & north central bus.

[Stan]

Kyle4501 My MC7 Combo had a 4501 rear suspension and also had zero rust in the air beams. There are two factors that save the air beams. The bus must be initially constructed in such a way that water does not get between the floor and the top of the beam. If it stays dry on top, then it is the reponsibility of the owner to keep the mud, salt and other crud of the lower part of the beam by regular washing.

[kyle4501]

I think the salted roads did mine in. The holes are on the side about middle ways up. Odd place if you ask me.

Rides smooth as glass even with blockoff plates.