Don't remember how much is recommended for the acid, but a search should find an appropriate thread. As for the maint..., well I have not been the worlds best on this particular item myself. Have rarely done the flush on a three year cycle, probably only did the 220D twice in the 20 years I drove it. But then water quality varies greatly across the country and I have never had any serious rad or cooling problems over the years.

However if we get to talking about brakes, then you have my attention and that is one area I have always checked pretty often.

ok, some thread said about 2.2 lbs per flush.

I think I'll go ahead and order 10 lbs, between the 4 cars, I won't have to buy any for a while. While it is cheap enough, it is the shipping cost that is always the killer here!

We have never had brakes wear out so fast living here! Reason: we live at about 1000ft, and every day, if not several times a day, it is up and down to sea level.

The other thing about this car is that it is not driven all the time, it is a spare. It is 29 years old, and has averaged only 6K miles per year. Yes, that is only 500 miles average per month. So the maintenance schedule is somewhat unique.

Put in a new shroud. Brand new they are $20 from Importec, at least they were for my 240D. You need your fingers and you need ducted cooling if you're in traffic.

Just edited my post to add the pix (distilled water flush after about 9 times).

Comments?

Looks like a not too fresh egg sunny side up. Seriously though, that is some heavy duty rust and not nearly close to where you will need to be at the end. The citric acid should help some, but just repeated dilution should also help quite a bit.

Have you measured how much water is added on each of the fill and dumps. Might be useful to know how much of a dilution you are actually getting, and therefore what reduction of the polution can be expected on each of these fill and dumps.

Would it be a bad idea to use HCl as a radiator flush?

I've got gallons of pool acid (Muriatic acid, 30% HCl solution) that I could use for a pretty hefty cleaning on a system, if I knew it wouldn't do anything terrible.

I read on here someone took their rad off, filled it up with an HCl solution, left it overnight and took it off and it was like brand new...I'd do that, just with it still in the car.

I used a diluted a solution of HCL it once in an old engine and it ate holes in some of the freeze plugs.

Hydrochloric acid is way too strong an acid. All we are trying to do is get rid of scale and rust, not open up all the passages in the block and radiator by metal etching!!!

I am adding approx 1 gal of distilled water for each flush, usually done once a day.