Yellow coolant tank restoration / cleaning [Video]

[JC220]

I wonder would this work as well on old MB yellowed expansion tanks?

Some members have said their new replacement tanks tend to crack at the hose connections whereas the original tanks are still going strong but look like crap.

https://www.youtube.com/watch?v=JqCN7VHMtfQ


Has anyone had success using some sort of cleaning agent on their tanks?

 

[gsxr]

I haven't attempted this, mostly because I don't think it's easy to obtain the chemicals in USA?

That said, the only concern I'd have is for coolant tanks with integrated silica packs. Might need to experiment with a damaged tank and see how the cleaning chemicals react with the silica. There was prior discussion about this on the forum, IIRC...

 

[500AMM]

The H3NSO3 sulfamic acid is sold on eBay; Sulfamic Acid H3NSO3: Search Result | eBay

Good point regarding the silica, but luckily it's not in the W124 coolant tanks AFAIK.

 

[gsxr]

The H3NSO3 sulfamic acid is sold on eBay; Sulfamic Acid H3NSO3: Search Result | eBay

Good point regarding the silica, but luckily it's not in the W124 coolant tanks AFAIK.

I think some original 124-chassis coolant tanks from the late 80's may not have had the silica packs (at least on gas engines). But I'm almost positive the later tanks do have the silica packs. This extends the lifespan of the antifreeze (possibly far beyond the original 2-3 year change interval).

I'm not sure if it's all tanks though, and I believe that while the original diesel tanks didn't have the silica pack, the later/superceded tank does have silica. I cut one open but apparently forgot to take photos. I still have that cut-open tank somewhere, I need to find it & get photos. Also need to check a new 034/036 reservoir I have on the shelf.

Note that the mid-00's cars had similar cooling systems with G-05 and silica packs in the reservoir/tank, yet were rated for a 15-year (!) change interval.

 

[500AMM]

OK, I have a new tank waiting to be istalled and to me it looks empty. How much and where is the silica pack located inside the tank?

.

 

[gerryvz]

I have never seen a silica pack in a W124 coolant expansion tank (nor W126), and I've installed replacements in both my cars. As well as the one in my G-wagen -- again, no silica pack. I believe this was likely introduced with the debut of the W210.

 

[500AMM]

BTW, I replaced the coolant reservoir on my (now sold) Limited years ago, and I am pretty sure it was empty.

.

 

[gsxr]

At least some 124's do have the silica pack. I have proof, I just need to find it.

I am not sure which chassis/engines have it though...



The .034/.036 plastic coolant reservoir/tank # 124-500-15-49 DOES have the silica pack, at least new ones from the dealer have it. The silica pack is visible directly below the metal neck where the cap screws on. If you shake the tank you can hear the silica beads inside rattle around.

 

[gerryvz]

Can you confirm that the reservoirs that were originally shipped with the W124 cars (all or some model years) came equipped from the factory with silica-based expansion tanks?

 

[gsxr]

Can you confirm that the reservoirs that were originally shipped with the W124 cars (all or some model years) came equipped from the factory with silica-based expansion tanks?

Would need to find an 034/036 (or other 124) that still had the original tank. By now, many/most have already been replaced. Probably someone out there still has a wirgin reservoir in their car though.

UPDATE: It appears all 034/036 reservoirs had the silica pack in the reservoir from the factory. It may only be early 124 production (1980's?) that may not have had the silica pack from start of production.

 

[500AMM]

I checked my expansion tank right now and you’re right Dave, it is a small cylindrical container enclosed with silicagel. It is fixed vertically inside, and not a lose part as I first thought. IIRC I bought that tank back in 2007.