I've removed lots of radiators on my previous MBs but, as is indicated in most of the posts, they have been held in with clips, which made removal easy. My '92 300SD has some kind of plastic posts on the top which fit in holes in the frame. It appears to sit in holes in the bottom frame, so I obviously have to release something, but I can't see how it all comes out. I'd appreciate some instruction.

BTW, it's running hot when under load (hill climbing) and I want to look between the A/C condenser and radiator or crud, before I get to some really drastic remedies. I've already flushed it with no apparent result.
instruction.
Thanks, ARW

Haven't removed mine in a long time . . . so the details are bit fuzzy. .

I'd remove the shroud since it 'hooks' into the 'slot' on the rad. MENU#20 shows how to get the outside and VFC off. And, of course, the rad hoses.

Also don't forget the tranny cooler connections on the bottom.

Should lift up and out . . .

If you tried the suggestions in MENU#17 under "Common Problems", then it could well be the radiator has reached the end of life esp if it has 'seen' tap water.

I'm sure you'll find some leaves and other debris in there so clean it out and see what happens.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Thanks for the reply. However, I looked round for common problems and menu 17/20 and was unsuccessful. Cn you give me a pointer in the right direction? Thanks, I live in the boonies where broadband is not available, so browsing is not as productive as it might be.
Allan

Begin by draining the radiator and coolant reservoir. This write up on alternator bearing replacement has a section describing the best way to do this.

http://v12uberalles.com/Alternator_Bearing.htm

This write up on viscous fan clutch replacement will get you started removing the radiator

http://v12uberalles.com/fan_clutch.htm

Remove the cross brace and the fan shroud. Then the rest is pretty obvious, except the transmission cooler hoses. These hoses are attached with banjo fittings and copper crush washers. The washers should be replaced with new ones when putting it back together. Have a drain pan ready. Not very much comes out (100 mL), but it is messy. And, the fluid should be refilled when you are done. This is a good opportunity to check fluid level and top it off if you have never done so.

Brett

__________________
1997 S600 sedan

Not sure what you mean; Click the link in my signature and select the desired "MENU" item; #17 will shows "Common Problems"; #20 shows the how to get the shroud and radiator exposed.

Hope that gets you started in the right direction. . .

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Thanks for the help Jim. I think I'll try make the mod to the bimetallic strip. I note that the temperature seems to be OK when I'm cruising along at 50 and above, so maybe the problem is the VCF. However, I still want to figure out how to get the radiator out, or at leastt away from the condenser so that I can look in between. ARW

Just to follow up on*fixing the VCF:
Your discourse on your web page was quite helpful and gave me the impetus to get the thing done. However, I could not find any way that seemed "proper" to fix the fan pulley while trying to remove the Allen bolt holding the VCF. In fact, when I got it apart, I could not find any way to restrain the pulley, even being able to access both sides of it for inspection. What I did do was to hold it very gingerly with a pair of vice grips, being very careful not to deform the pulley and then fix the vice grips with a screwdriver. It's not elegant, but it worked.
I found that the bimetallic strip was not as pictured, but was rather more of a equilateral parallelogram with the fingers at the ends to fit under the retainers. There was a cross bar over the pin on the VCF with an adjusting allen bolt in it which bears on the VCF activation pin. The adjusting bolt was frozen and too delicate to muscle out, so I ground the bottom nib off and the VCF adjusting pin now appears to be fully extended.
When the VCF pin is fully extended, does it lock the fan mechanically, or through the viscous function, i.e., with pin fully extended, should I be able to rotate the fan independently of the pulley?
BTW, while I was at it, I figured out how the radiator comes out. It's like the one you show on your 500 and the thumb screws in the middle of the posts which pierce the upper radiator support member unscrew and allow the radiator to be lifted out at the bottom, I believe.

Yes, there's a special tool for that but vice-grips are just as good . . . in other words, whatever works!

Sorry, don't understand what you wrote . . .

The pin pushes on an internal 'switch' (clutch) when the bms is cold (ie no bend) and DISABLES the VFC (It's not "VCF" . . but VFC for "viscous fan clutch"!). When the bms reaches it's 'bend' temp (100C or more), the bms now is bent and this releases the pressure on the internal clutch causing silicone to flow and LOCK-UP the fan.

If you mean that you ADDED the bolt/nut as shown in MENU#20, then the answer is "yes", the VFC is fully engaged IF there is silicone in the VFC. If not it won't do anything.

You will KNOW that it is locked as soon as you start the car; the 'swooshing' from the fan will immediately alert your ears. It was because of the constant air-noise that I modified the method.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Let me try again on the bms. It is a diamond shaped strip with nibs on each end to fit under the holders on the VFC housing. The diamond is annular so that a similar but smaller diamond is cut out of the center producing a diamond shaped device that is hollow in the middle. In fact, the area over the pin would not have any bms above it if there were not a cross bar incorporated. A set screw is set in the cross bar exactly over the clutch pin.

I don't see any difference in the behavior of the fan with the modification I made. Given the configuration I have described, there is no place to make the modification you suggest as there is virtually no bms with material on the center line so that you could properly lift it off the pin. This is really difficult to describe and I'm not going to go out and take it apart so I can take a picture. I included a drawing for clarity (I hope). Of course, this is a rather crude drawing—the ends are cut off to fit under the retainers on the VFC. The area between the two diamonds is the bms.

Regarding the result: i don't see any difference in the behavior of the fan, so I think that the viscous is working. That is, I don't get any whooshing and the fan does not lock up with the pulley as far as I can tell. The set screw which I ground off does not depress the pin on the vfc. Does the VFC nit die and just not work?

Thanks again, RWA

Attached Thumbnails

 

Tnx for describing your VFC mods.

Some background info which may be missing: the purpose of the mod is to 'force' the VFC to be fully engaged by mechanically raising the "pin-clutch" so that fluid is forced to lock up the fan full time independent of engine temperature.

So with that said, if you 'raised' the BMS up as shown in my pic (Menu#20), then the VFC should be engaged, full time and should turn the fan at the same speed as the engine independent of engine temperature. So the fan should make a "swooshing" noise.

If there's NO difference, then that could be two (2) things;
1) you didn't really raise the "pin-clutch" up enough to cause it to engage . . .
or . . .
2) you DID raise it up enough but it's out of silicone fluid, so it can't 'lock-up' the fan. It can be fixed by filling it with silicone fluid (from 'toyota')

If it's either of the latter, I'm sorry for your wasted time. . .

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Two things.

First, it seems that, if you take the bms off (which I have enough room to do without taking off the fan), then, if there is enough fluid in the VFC, it should lock up. Correct?

Second, by "lock up" do we mean that, with the engine off, you can't turn the fan because it is mechanically (not through the viscous coupling) locked to the pulley?

Finally, time was not wasted at all. If the clutch is out of fluid, I'll fill it and I should be back in business.

Thanks for your advice and time. ARW

yes after it's been spun . . .

same answer as above; spin it at 1000 rpm or so, until the fliud migrates into the chamber so that it can 'lock'. It won't migrate unless it's spun.

I suspect your VFC may be 'empty' since the failure mode is simply that the fluid leaks out slowly with time. Here's a link to refilling the VFC:
Viscous fan clutch - rebuild

Glad you had a good time . . . .

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Ah, now I see! Thanks for your patience.

You are likely right about it being empty. Otto has been 325K and is still in good shape.

In the thread to which you referred me regarding refilling the clutch, one of the messages refers to drilling a hole in Chamber #1. How do I locate that chamber or does it make a difference? Also, is it necessary to seal the set screw used to open and fill the chamber? Is threadloc enough?

Thanks once again!

. . . 325K . . . miles, I presume, that's a well travelled MB! Congrats


My limited expertise has just run out . . . you can tell ME how to fill one since I've never had to do that . . all of mine still have fluid. . probably b/c they're are not even close to 325k miles.

I would think drilling a 'relief' hole would be the thing to do; then plug it when filled.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page