S-Prihadi

Guys,

I was doing my friend HVAC system, W204 C200 of 2010.
He bought the car used in 2012 at 2 years old and in 2016 the HVAC system total loss. Compressor + EVAP & TXV and Condenser replaced, I bet the suction hose too as it has some sort of
round thingy contraption. I am sure the total loss was from Black Death. Either his refrigerant was leaking slowly and then compressor oil then majority got stuck at EVAP and compressor died from
lubrication starvation.....or MB Indonesia did not dry the system properly during assembly and the oil then became acidic and kill the compressor at year 6th.

Anyhow, being 8 years old since last replaced, I told him let me verify the R134A fill. It lost 90 grams in 8 years, assuming the repair shop did not overfilled 8 years ago.
The last job done was decent, but not as dry as I can do.


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So I vacuumed down to 222 micron, insanely low for an 8 years old system.
Thanks to my TruBlu hose, the best bad-azz vacuum hose money can buy and the good bang-4-the-buck a bit fat yellow jacket black vacuum hose. 3 times nitrogen purge too.

222 micron is with the black yellow jacket vacuum hose valve shut down. So I am vacuuming only at LP port, where micron gauge at HP port.


If I open up the vacuum valve at HP port for the black vacuum hose to participate, the micron reading will be lower but not an honest low. See 181 micron below.





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I then added UV dye.



A good vacuuming down to under 300 microns will take 1 vacuum pump oil change per car I do.
Now we can see how effective is the vacuum pump oil in sealing the vacuum pump and capturing the water moisture.





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Anyway, this W204 has exact same evaporator and same family 6 pistons Denso variable speed compressor too, also the same 590 grams R134A fill.
Basically the cooling power is the same as my E400.
But because it has heater water-valve to stop water circulation to the heater core....DAMN, this car has cooler air blowing air out of its AC vents , no cross contamination from the hot heater core a W212 is like.
I discussed this some years back, the lack of heater water-valve in W212 is a dumb-azz small money savings MB should never do, for a car in the tropics.





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This is the heater water-valve




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So this W204 is a good example of how good actually the W212 HVAC system is....when and if I can either by-pass heater core ( not elegant ) or DIY in-place a good water valve ( not easy ).

Damn.... I am drooling.

CaliBenzDriver

Thank you for letting us look over your shoulder! Your friend is lucky to have you vacuum his system perfectly dry.

I recall the lack of coolant valve we looked at. I had pinched my heater core hose only to realize it's the whole Bank2 head circulation.... heater bypass is the only way to go. Coolant must flow through something.

As for now, the up side is we are guaranteed our missing valve is not leaking into its actuator.

S-Prihadi

That's the problem.... complete heater core shut off is not allowed, as the coolant is needed to go back to mechanical coolant pump, so I must find a special 3 way tee with electric valve...dugggh.
The hose end fitment is the issue.

Easiest is bypass the heater core.




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Must make a U shaped by-pass pipe, so that my hoses stay original and no need to cut to make it straight, for when and if I wanted heater core to be back in action.

S-Prihadi

U shape pipe NO CANT do, space too tight.
Even if I buy this U pipe and make it short, its W is too wide.





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I got the measurement above from the other pipe I have on hand.



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I might get away doing heater core by-pass with no special hoses or U pipe to buy and crowding the already cramped area.








The long alu pipe short hose end I remove and use the hose from the fake firewall hose assy.






I hope the hose wont be stressed.






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Second method but will need to order special black coolant hose and the new hose will STILL be visible, UGLY man.....
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Look easy drawing it, but the new hose must bend down 90 degrees to negotiate the ALU heat shield and then up 90 degrees to be straight...Dugghhhh





This DAMN Tee is too fat for a proper 19mm ID hose.



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Must do the by-pass while I replaced all of the coolant hoses due for 10th year.

CaliBenzDriver

MS, you are going to laugh all day long with superior A/C once you are done by passing extreme heat source.


exposed pipes dumping 200F heat inside... LOL

S-Prihadi

Must order the new pink coolant first.

What would you do Cali, for this case :

01. There will be now way for me to empty the heater core of coolant to proper dry level, not with the design and height of the pipes well above the body.
Even pressurized air wont help.




I think heater core bottom is approx at the height of the engine block to cylinder head mating point, or lower.


02. So I probably must keep it with coolant, if possible near full and plug off the 2 pipes to not have liquid sloshing sound.
So must buy this pipe end cap
Actually I do not like to use silicone hose much, it is very slippery.


Every 3-4 years I must re-fill it with new coolant I think, as there is no corrosion inhibitor "injection" anymore in effect, if the coolant stay still and never circulates to the coolant reservoir bottle
corrosion inhibitor chemical pack.

I shall not allow my heater core to be damaged by corrosion, even when by-passed.


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Audi version corrosion inhibitor chemical pack







W212 oval bottle version corrosion inhibitor chemical pack.




Dumb-Azz MB Indonesia poor water mix and low coolant % , since new in 2014. Caused me leaking coolant circulation pump in 2019/2020 and rusty steel hose end for radiator hoses.
Look at the freakin dirt the water has.









Above slime I already cleaned it. Before it was so much worse.


Was like this :

Old version yellow coolant. Dates should be 2018 , not 2017




My engine coolant reservoir bottle is now new sometime in 2021 / 2022.
I do not want the inhibitor bag to tear and cause cooling passage blockage like on Audi/VW.
Also its "injection" life maximum is 15 years.


.
M276 3.0, M278, M157 stand alone aftercooler coolant bottle and its corrosion inhibitor pack. My new one soon to install.


No more using cloth like bag for corrosion inhibitor, it is plastic cage hahahahah.

CaliBenzDriver

MS asked how to preserve disconnected W212 heater core that can hardly be emptied ?

What's best is a tough call !


The way HC is plumbed/piped is to help air bubles get out.
It's nearly impossible to drain liquid out with pipes positioning.

I think if I were you I'd rince the coolant out and let it be more or less filled with tap water that won't smell when and if it wants to leak, water only.

I don't see you plumbing the heat back in once you have HC bypassed. So old HC is "retired" and non existent.

Filling up with blue coolant may help preserve aluminum fins but without circulation liquid will stratify heavy additives at the bottom light water at the top - Then leaking conditions.

Since we really don't care about HC conditions because it won't go back into service...
do you want HC to leak water or coolant ??


How about distilled water? It has no electrolytes ions and will leak clean!

CaliBenzDriver

The coolant companies are really having fun with their rainbow colors.

The Yellow and Blue are exactly identical with zero improvement.

Now the Pink coolant, I don't know it... Is that the silicone based chemistry??
​​​​​
​​​​​​Any perceived benefits to change over ?

S-Prihadi

MB stop selling blue one at end of 2023, globally.
Yellow been gone for much longer.
So now they sell only the pink one.

The chemistry ? Read here : https://mbworld.org/forums/e-class-w...k-coolant.html

S-Prihadi

Believe it or not, chemistry is a bi-etch.
De-ionized water and distilled water is actually quite corrosive, if used stand alone without coolant and its corrosion ihibitor.


https://www.chemicals.co.uk/blog/dei...e%20atmosphere.

Near zero of everything in distilled water causes this :
Despite its benefits, distilled water is particularly corrosive. With no minerals to give the water pH balance, distilled water acts like a magnet, absorbing chemicals (phthalates and bisphenols) from plastics, nickel from stainless steel, aluminum from aluminum containers, and carbon dioxide from the air.
https://www.corrosionpedia.com/defin...istilled-water

It is true actually. I deal with Reverse Osmosis system and the water produced has TDS so low like 10PPM only.
It is not too kind to metal plumbing. Water loves to try to balance things, it is after all a universal solvent.
But high TDS water with the wrong kind of TDS, is more corrosive and more so when being heated up, like in water heater.

I hate chemistry since school. It is something we can not see. We must learn all the damn formulas.
02 is oxygen, 03 is ozone. I used to use ozone in my swimming pool, this gas destroy any plastic fitting FAST and has short half-life, but its oxidation/killing power is awesome.

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I think the better word for my heater core is De-Commision it for later use or never....ha ha ha.
Its not technically ethical to not maintain my components in the car, even when I plan to not use it.
There could be a day I might use it again say at 15th year ? Maybe.

I think I need to go to the troublesome route of replacing the stagnant coolant in HC per 3-4 years.
I never seen coolant additive out of suspension Cali, but I seen it boiled off ( from leak ) and leaving the blue stain or some other cars with pink one
leaving pinky stain.

Damn...always a dilemma when we want to do it well.

S-Prihadi

Ok that HPS , 19mm silicone Amazon plugs ordered. Cost US$60ish landed with tax. So awesome Amazon shipping and pre-paid import duty system.

OE website : https://hpsperformanceproducts.com/p...ete-black-blue

Will arrive latest 4-10th May 2024.


I have ordered the new pink coolant too. 5 liters, so can make 10 liters pre-mix 50/50.
I think I want to play two coolant colors.
Aftercooler keep the blue coolant, as I have 1 liter concentrated back up as last batch local MB dealer can provide me.

Engine and HVAC system get the pink coolant. So if any one ever leak ( touch wood ), I can tell by the color heheheheh.


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Cali, MB has special tool for wiper removal. It is so expensive at US$200 ish.
So I bought locally ( arrived ) exactly the same 2 types like Amazon is selling, see below :


The small one needed its U shaped cavity to be made a bit deeper. I already did. As MB wiper arm is a bit fat.
Grinded it down with my angled grinder but the smallest blade is still too big and the cut is angled no choice...LOL.
So I ended up using dremel round stone. result is OK, not clean or professional, but it works. I hate metal works.




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Only like 2-3mm metal I have to remove.


Still the black small stud will not hit perfect center zero on the wiper shaft, but not bad. We can use washer to assist to create a more even push if needed.
The green dot is where the zero I got after machining down the U cavity.



.
The big one not nice to use for wiper removal because of the size, but it will work too.... it may be also useful for some other application/s.




If your wiper arm has never been removed, it wont be easy to pull out.
I had to use my ball joint tool do help.




So get that tool set to help you when you want to do the wiper greasing & cleaning its electrical .


Or get this one, it is slimmer and will always get the Zero center.
https://www.ecstuning.com/b-schwaben.../018544sch01a/

S-Prihadi

Damn stupid me, I do not need to grind the U shape cavity down.
The limitation IS the position of the stud bolt hahahahah is not outward enough.
The side wall of the tool will hit the wiper arm frame well before its U cavity will ever hit the wiper motor shaft...duggghh!!!