Changing out the Alde fluid.

pthomas745

The link below will show you the link to the DIY File, and explain closely which of the two holes in the expansion tank is the "in" from the glycol loop and which is the one "out".

DIY Glycol Exchange File

You said you "vacuumed out" the glycol from the Alde, did you use the "shop vac" method? This comment shows what I mean about the "shop vac" method, which is basically sucking out the glycol from the system. There is a description of which of the "holes" is used to draw the glycol out.

Shop Vac Method Description

pak

I slowly removed a hose while the shop vac was on. This prevented any spillage. I suspect there is maybe 1/4-1/2 gal of glycol laying in a low pot or two. I'm just going to fill with new century fluid. This is my second replacement since 2017. The old glycol is clear, free of sediment, ph is about 9 and the convector ends have only a small amount of staining. I am electing to paint the convector ends for additional corrosion protection. Thank you for your help. Pete

qhumberd

https://tab-rv.vanillacommunity.com/discussion/comment/222604#Comment_222604

Here are images I took in our 2019 to remind me of flow direction. The R hose returns to the Alde and the L is the final connection from the loop. Therefore in flushing (Pic 2 below), the old glycol is being pushed out of the loop by the distilled water going in.