Compelled to Upgrade the Radiator

[Dragonwing]

I'm back, after a long hiatus---largely because things have been going pretty well with Nimbus, my '83 Wolfsburg. That is, until the other day, when the radiator decided to explode......spectacularly, I might add.....taking the grille and both headlight surrounds with it. So, I'm looking for a replacement radiator for her, one to match what I had under the hood, and I note that a direct replacement (The one with the filler cap on the radiator's crummy plastic expansion tank)....assuming I can even find one .....is way too costly for what I'm getting. Especially, when other radiators are offered for, say, the '84, at about 1/4 the price. So, looking at one or another of the Cabby forums, I note that it's possible to install a newer-style radiator (with the same 525 mm dimensions), as well as an expansion tank (yes, the bracket is there, under the hood) and hoses, and be 'good to go'. The problem is that I saw no recommendations for the radiator to use---like a Nissens, or Modine, or Valejo part number would be really helpful, so I'm not shooting in the dark and spending my cabbage on a rad that doesn't fit. Can anyone steer me toward the Light? Thanks!

DW

Oh, almost forgot: Yes she has A/C----for what it's worth. If that makes a difference.

[Briano1234]

Well the old adage is that you bought a A/C radiator to begin with as it is a tad longer and a thicker core.
I have both the Valejo and the Modine on each of my cabby's and the Nissens on a Pathfinder I had. I ordered the cheapest one I could get.
If you are going from the older style that bolted to the Valance at the bottom (bs design) to the newer pin seat be sure that you get the rubber grommets that fit.

I have seen replacement solid Aluminum Radiators being sold at some places for about the same as the Plastic/aluminum ones. As much as I hate plastic parts, I have consigned my self that when the next one goes I will be thinking more about them.

Now expansion jugs are catch as catch can, and I thing I bought my last jug and Cap from O'Reilly's 12 bucks with the CAP and LLW.
but I suspect that you need one sans the water level sensor, as they come both ways.

I think the Radiator on the Green one Modine has been on the car for about 11-12 years now. The Blue one is a Valejo who is about a year younger.

Be sure that prior to replacing it you Flush and Back Flush the coolant system in the car, and replace the t-stat. Prevent the Burp and drill a 1/8 or 1/16 hole in the lip of the t-stat.

Blew apart? I wold have to think that you may have a bad head gasket or a bad oil cooler that is leaking in to the cooling system I have never seen a Radiator blow....I mean there is only 14psi on a cooling system.

Once you get it all back together. Engine cold, remove the expansion tank cap, and tie a Latex glove over the opening tightly.
Car in Neutral, Parking brake fully on.

Start the car.
Under the hood rev the engine to above 3000K for 30-45 seconds, if the glove inflates and gives you the finger then you are looking at a oil cooler leak or a bad head gasket.

[Dragonwing]

Briano:

Thanks for the prompt reply. A couple of things, though. I guess that now my biggest question is--since the '83 seems to be one of the few that has (had) the plastic expansion tank with the filler neck and cap all attached to the radiator--can I use the '84 and later rad, assuming that I'm going to mount a separate exp tank and hoses? Also assuming that it's the 525mm size for the A/C equipped car?

And the other thing is that it was that 35 year old rad expansion tank that actually exploded. I guess the old plastic had just had enough.

And the final thing is that yes, I'll be replacing the hoses and the 'stat and I probably, just for laughs, replace the temp sensor that activates the fan. Anything else that you can recommend I look at---just to be on the safe side?

DW,

[Briano1234]

No that sounds about right I would do the glove test to validate that you don't have other issues that caused it.

But if it was the original radiator, I guess it could of blown out the plastic as that becomes really brittle.

[Dragonwing]

And finally....FINALLY....I now have assembled the following: Radiator (525mm), Radiator fan switch (82-77C), Thermostat (80C), Expansion tank, Upper and lower radiator hoses, Hose from radiator to expansion tank, Radiator grommets, Expansion tank cap. I was thinking that that should do it, but then I read in the Cooling System section of Cabby Info, the mention of a 'coolant return pipe' that is part of the system. I have no idea what this is, or if it is even required on the '83. Help, please, or maybe a photo of an intact cooling system as a guide?

Thanks, as always!
DW

[Briano1234]

The coolant return line to which you are referring to is the steel pipe that runs from the heater by-pass hose on the waterpump to the heater valve and the expansion tank connects to it as well.

see https://volkswagen.7zap.com/en/usa/rabb ... 21-121022/

[Dragonwing]

Thanks.B. I see it now. #8 on the diagram.

DW

[Briano1234]

Napaonline used to sell those, but they had an extra spout that had to be capped or closed, and the price was reasonable.
https://www.napaonline.com/en/p/ATM027121065D

Took me about 3 minutes to locate it....

[Dragonwing]

Just found a place in North Carolina that sells the factory originals for $9.00. New. Couple of bucks to ship, and I'm golden. I'll share the site when i call them tomorrow to see if they're legit. Got the pipe, a lower rad hose, the connector hose from the coolant pipe to the water pump, and the overflow tank cap---all factory or made for VW--- for $19.00. Yow!

DW

[Briano1234]

Hans? They don't have a good or great reputation, as I have had issues with them in the past.

[Dragonwing]

Yep.That's disappointing, but thanks for the heads-up. I'll call them today and get a feel for what they're about.

DW