I am in the process of rebuilding the water pump on my D2 5U. This is how I found the bellows seal cage when I took it apart. Does this look correct, or do the "lobes" need to be seated on the larger slots?

The seal is badly worn, the brass housing is ok. Just replace the seal not the housing.

Copy that Rome, are the "lobes" orientated properly?

Yes they are. Just bend the little tabs straight and remove the old seal install the new one and bend the tabs back again.

No, the scallops and lobes are supposed to be aligned. That’s what allows the brass cup to “drive” the seal element. I have always seen that CAT parts book lists the seal ring separate, but when you order one it defaults to an assembled unit that you press into the housing. Just be careful you don’t allow your socket or sleeve etc you’re using to drive or press it doesn’t contact the carbon ring. I like to wrap a strip of card stock or wind some paper around it before putting the socket or sleeve over it to cushion any shock.

Is the ceramic seat on the impeller intact?

The service manual states that you don't have to replace the whole brass assembly, just bend the small tabs and replace the seal.

"d4angelo" wrote:

Copy that Rome, are the "lobes" orientated properly?

Regardless of orientation, it needs to be a loose fit in the brass housing so it can make itself square and comfortable against the impeller once fitted. So I wouldn't fold the little tabs too tight against the new seal.
Regards

"Riverina wrote:

Regardless of orientation, it needs to be a loose fit in the brass housing so it can make itself square and comfortable against the impeller once fitted. So I wouldn't fold the little tabs too tight against the new seal.
Regards

That's what I think. The fact that the seal is worn and wedged into the brass leads me to think that it wouldn't float and seal correctly

This brings me to a question I have. As I said, all of the replacement seals I’ve ever seen before this last year have been a unit. The seal carbon ring and rubber bellows have been glued into the brass cup. Last year I ordered a few from an aftermarket supplier and the “guts” is loose in the brass cup with just an o-ring on the base to seal it. I’m guessing this is the way they are supposed to be? Seems a bit shaky to me compared to having it cemented in but what say you? I’ve got a couple on hand.