w116 300sd Thermostat Housing

[Gito]

For those familiar with old Mercedes from 1970's-1980's
Own a 1979 300sd (w116).

The thermostat housing (6172002415) is pitted/corroded at the inlets/outlets.
Although the rubber hoses are properly secured and tightened using good clamps, coolant continues to leak out.

I drained the coolant and replaced all coolant hoses approximately 6 months ago and I was surprised to see encrusted buildup at joints between the hoses and the metal openings (inlets/outlets) to the thermostat housing. Obviously, the buildup throughout the years is responsible for such corrosion/pits.

I thought about using some type of epoxy to smooth out the pits and even out the corrosion so that the hoses can get a tight fit but I wanted to know if anyone out there has encountered this problem before and what is the best way to handle this.

Before I go out and buy a brand new thermostat housing, is there a better way to smooth out the pits or a better way to secure the hoses so that future coolant leaks can be prevented.

Also was wondering if I should use a silicone piece of hose (42mm) instead of a rubber hose between the thermostat housing and the metal line located directly under. Thats the area where I'm getting most of the coolant leaks. Hope I'm describing the area correctly. A short rubber hose (42mm) secured with two clamps on each end allows the coolant to flow thru. Is there an advantage in using Silicone?

See link below if need better description of where the thermostat housing is located on a w116
http://www.peachparts.com/shopforum/dies...treet-pics.html

Any advice is greatly appreciated

 

[bullwinkle]

Could it be cleaned up? Maybe replace with a good used one? Like here-
http://www.oldbenz.co/thermostat-housing-om617-6172002415
There used to be a cheap MB boneyard in Falmouth, KY called European Connection that I bought parts from, but I think he's gone.

 

[Gito]

Originally Posted By: bullwinkle
Could it be cleaned up? Maybe replace with a good used one? Like here-
http://www.oldbenz.co/thermostat-housing-om617-6172002415
There used to be a cheap MB boneyard in Falmouth, KY called European Connection that I bought parts from, but I think he's gone.


Thanks,
I saw that thermo housing on that website but noticed some corrosion on the ends.
I cleaned up my thermo housing as much as I could but the ends are pitted/porous.
Maybe the porous surface is allowing the gunk to build up easier and therefore through expansion and contraction, the gunk starts to slowly crawl into those areas.

I thought about using a 1 1/2 inch rubber hose instead of the 1 5/8 in hose. The 1.5 inch just needs a little more force to position but it does slide in.
Not sure if a tight fitting hose compromises the integrity of the rubber.
The smaller diameter hose does swell up once its positioned on the end of the housing metal line (coolant pipe opening).

Also thought about buying heavy duty clamps ($7.00 a piece) and maybe just give it better clamping force.
The Genuine Mercedes Clamps gave in when I tightened them more.

I just don't want to be flushing, filling and bleeding multiple times.
You would think that a tighter fitting hose and some stronger clamps would solve the problem.

This area of the cooling system really gets build up/calcification/crud/etc.
I had to carefully scrape of gunk that built up in less than 6 months.

Again, any advice is greatly appreciated

 

[bmwpowere36m3]

Pretty normal occurrence...

My advice: new hoses, new quality clamps (Gemi/Norma/ABA) and a bit of hylomar. Permatex gasket dressing & flange sealant works for me (similar to hylomar blue).

 

[Gito]

Originally Posted By: bmwpowere36m3
Pretty normal occurrence...

My advice: new hoses, new quality clamps (Gemi/Norma/ABA) and a bit of hylomar. Permatex gasket dressing & flange sealant works for me (similar to hylomar blue).


Non hardening, non setting hylomar?

 

[Gito]

Ok thanks. I think I can use Permatex PermaShield Gasket Dressing and Flange Sealan

 

[eljefino]

Hylomar's good but so is regular old black or blue RTV. Sand down the high spots, fill the low ones.

 

[Gito]

Originally Posted By: eljefino
Hylomar's good but so is regular old black or blue RTV. Sand down the high spots, fill the low ones.


Thanks

 

[14Accent]

Quick set JB Weld and some sandpaper? Might take a bit of time but that should give you a nice clean surface when complete.

 

[Imp4]

Here's a used one for $50.
Looks like the inlets and outlets are in good condition but YMMV.
300SD thermostat housing linky