Air system Dryer ??s for those who have installed them on vintage bus(es)

[dtcerrato]

Was getting ready to install a dryer on our 53 GM4104 when I realized that the fittings and passages on the dryer (Meritor Wabco System Saver 1200 Series) are much smaller (1/2") than the original equipment plumbing (5/8" - 3/4" lines through out. Any feedback on this? Don't like downsizing but want to dry up any moisture which doesn't seem to be a lot anyway. Is it an overkill when the old system can be drained. We have automatic BW drain on wet tank & manual drains on dry & accessory tanks which hardly show moisture. Comments welcome. Thanks

[chessie4905]

We installed a Bendix ad9 recently. The line size was one size smaller than original on coach. I dont think that is going to be a problem. These driers are used on semis with two or three trailers behind them with no issues. You could use fittings that have the reduced thread to attach at the drier with the same line size as coach.
Btw, on our 4104 drier was mounted near left side of radiator looking at it, right behind rear wheel bulkhead. We carefully cut lower body panel and hinged for access to drier. Looked factory when done. We did same in 4905, attached to bulkhead just behind left rear duals. Ours is accessible by raising radiator grille. No longer have factory ac.

[luvrbus]

If it is a Wabco 1200P it has to have a separate purge tank,plumbing down sizing at the drier dosen't affect the system 

[dtcerrato]

That's exactly where we intended on installing the dryer, between the rear duals (behind the rear bulkhead) & radiator next to the wet tank accessible from the outside with a door in the skin. The one thing we plan to do is add light gauge sheet metal underneath the assembly to keep dust & gravel from being kicked up in that area.

Our dryer unit has the regeneration valve & purges at the bottom to atmosphere so a separate purge tank isn't required (if I'm reading it right?) We will add a PCCV at one of the tanks downline to regenerate the dryer between cycles (if I'm reading that right also?)

Our auxiliary air compressor is plumbed in at the engine air compressor discharge muffler so it also is routed through the drier prior to entering the system.

Thanks for the feedback!