Heater Hose Dimensions?
 

As with most older cars, my 1994 e36 shows definite deterioration of the rubber hoses. I'm looking to replace as many as possible ASAP. The first set that I'm focusing on are the heater hoses (?) which extend out from the heater box back near the driver's side left of the engine; these seem particularly hard to reach. Can anyone advise me on what size these hoses happen to be? I'm looking to avoid a coolant leak and judging by the appearance of these, I may not have all that much time to find replacement. The Bentley manual also recommends emptying the freon and engine coolant from the system before attempting this job. Is this necessary for hose replacement? Just checking. Thanks!

I did them all on a 1997. I removed no freon or coolant. You must, however, remove the air plenum from the firewall in order to access the heater hoses. I removed the screws and pulled as instructed in the manual. Then I straddled the engine and pulled harder, and harder, and harder, until it finally broke free and I nearly back-flipped over the radiator.

The other tough part is the hose beneath the intake manifold. Mine was leaking. I had to remove the oil filter cover to get my arm back in there under the manifold to remove it.

With regard to sizes, they are all molded hoses. I got mine from Autohaus but you might find them all packaged as a kit at Pelican or FCP.