93 300SD radiator - PeachParts Mercedes-Benz Forum

flainn · #1 05-26-2015, 05:31 PM

Hi folks,

Our 93 300SD keeps blowing the upper radiator hose off (at the radiator). I had a look at the neck and it looks like a chunk of it is missing. I figure that hose isn't going to stay on anymore and the radiator needs to be replaced.

Do I need to use a radiator specifically for the 93 300SD, or would a radiator from any OM603 work?

vstech · #2 05-26-2015, 08:08 PM

Specific.

vstech · #3 05-26-2015, 08:09 PM

Are you certain you can't repair the neck?

Are you certain there isn't a blown headgasket dumping high pressure that is blowing off the hose?

flainn · #4 05-27-2015, 10:16 AM

Is there a reliable procedure for repairing the neck? I did a bit of reading, and everything I found indicated that once the neck is damaged, fixing it isn't feasible.

No, I'm not certain it's not a head gasket issue. But I haven't seen any coolant out the tailpipe, nor any indication of pressure in the overflow bottle. It's also not losing coolant, as long as that hose stays on. What do you think?

dude99 · #5 05-27-2015, 10:43 AM

Quote:

No, I'm not certain it's not a head gasket issue. But I haven't seen any coolant out the tailpipe, nor any indication of pressure in the overflow bottle. It's also not losing coolant, as long as that hose stays on. What do you think?

Might be worth buying a kit that detect combustion gasses in the cooling system, if you do buy one make sure its compatible with diesels as not all of them are.

vstech · #6 05-27-2015, 12:27 PM

light sandpaper, alcohol cleaning, and a bit of jbweld, to form the lip of the neck, are worth a try. get it shaped well, and you might be surprised.

oh, and I'd put on a new upper hose on general principals anyway...

dude99 · #7 05-27-2015, 12:47 PM

Also, take a picture of the problem for us, it might give us a better understanding of the issue

flainn · #8 05-29-2015, 10:08 AM

I'm going to try to find some time to get in there this weekend ... been sick for the past few days. Thanks for the help.

gmog220d · #9 05-29-2015, 11:02 AM

Here's a pic of a busted neck on a W123 240D I worked on for a friend. His wasn't blowing the hose off, despite the missing lip. We replaced that radiator for sure.

flainn · #10 05-29-2015, 11:09 AM

So they are supposed to have a lip? Mine seems to not have one, and it has a v-shaped chunk missing.

ah-kay · #11 05-29-2015, 11:24 AM

This is how I fix the 300D radiator. The neck broke off and I could not clamp the top hose back on.

1) Find a funnel with down pipe size similar to the hole. I bought one from Walmart.
2) Cut the section off that fit the hole, i.e. you end up with a TAPERED section to use as insert. Taper is the key.
3) JB weld the insert to the broken snout. Try to push it in to get a tight fit. It is tapered and the joint will be very strong with JB weld.
4) If the broken part is missing, then cut a section off from a JY radiator, may be any radiator will do.
5) Remember to lightly sand all surface to glue.

gmog220d · #12 05-29-2015, 11:52 AM

Quote:

Originally Posted by flainn

So they are supposed to have a lip? Mine seems to not have one, and it has a v-shaped chunk missing.

I couldn't find any pics of a good neck with a quick search (only pics of busted ones), but yeah, there's a lip on the neck that helps keep the hose from popping off when clamped. Some of the fuel line and other hose fittings are the same way.

A good neck is maybe twice as long as the one in the pic I posted above, and towards the open end the lip goes all the way around, making the diameter there a bit larger. The hose clamp squeezes down on the hose on the other side of that lip, so the hose and clamp would have to be forced over the lip to pop off.

Score a good neck from a junk radiator and JB Weld it on with a piece of tubing inside bridging the gap?

flainn · #13 05-30-2015, 02:01 PM

Ok, I found the time to get in there and have a look. It does not have a chunk broken out but clearly the neck has broken. There's no lip at all and the end of the neck is not even or smooth.

I haven't decided whether I want to attempt a repair or just buy a replacement radiator.

Also, yeah I know it's got the wrong kind of coolant in it (Dex-Cool) right now. Thanks, previous owner. Once I get this radiator issue straightened out I'm going to drain/flush/refill with Zerex G-05.

flainn · #14 06-02-2015, 12:15 PM

Any more thoughts? Does it look worthwhile to attempt a repair or should I just bag it and replace? This is probably an old radiator, so I imagine replacing it isn't that bad of an idea.

ah-kay · #15 06-02-2015, 12:33 PM

What other ideas you need?

Long answer - repair it as per many members' post, just pick one within the realm of you skill.
Short answer - replace it, it is your car and your money.