expansion tank cleaning

[Dav]

88 2.9 auto.
the expansion tank is so dirty that i can't tell how much water is in it. since LMC doesn't list a series 1 tank, i guess they are NLA.
is the top removable? don't want to destroy it trying to take the top off. what would be best to clean it with?

 

[Dirtman]

Remove and plug the drain/fill hose. Fill it with vinegar. Let it sit overnight and then flush it out with the hose.

 

[Dav]

well, i tried the vinegar. when i drained it, the vinegar came out clear but when i flushed it with the hose, the water was honey colored.
but i still couldn't see the water level.
"she who must be obey'd" said "try the stuff i use in the bathroom"
so i took the CLR stuff and squirted some in a series 2 tank i have. (not going to endanger my series 1 tank; series 2 trucks are only good for parts anyway)
the CLR cleaned the crud off the inside to the point that i could see water (if it was in a truck). i mean really clean never saw an expansion tank that was new but i think this is as close as i'll ever get.
no apparent harm to the tank, either
next weekend i plan to do the tank in the 88. only on the expansion side; i have never successfully removed a washer pump retainer and i'm not sure the pump would survive the CLR

 

[alwaysFlOoReD]

Thanks for the tip. I've used small gravel and soapy water and shake the shit out of it. It works good enough but isn't the best. Maybe the acid (CLR) will finish the job. I would suggest a good rinse with some baking soda after for good measure.

 

[Dav]

So i did it today. put some CLR in the tank and let it sit. flushed it and 'voila' i can see the water level. it's not perfect- probably should have let it sit overnight- but it will do for now