OEM Plastic radiator

[DMC3165]

Hi all. Last year I purchased a NOS plastic radiator that was sitting in the box for 30 years. It worked well at first but then developed a small leak. It looks as if the leak is coming from the useless cap on top of the drivers side. Can this cap be removed at all? Maybe a bead of silicone or a new gasket under the cap need to be replaced. It doesn't leak much and only noticed a small drip when the car is parked for a while after a run. Any info on this would be helpful.

[DMCMW Dave]

Hi all. Last year I purchased a NOS plastic radiator that was sitting in the box for 30 years. It worked well at first but then developed a small leak. It looks as if the leak is coming from the useless cap on top of the drivers side. Can this cap be removed at all? Maybe a bead of silicone or a new gasket under the cap need to be replaced. It doesn't leak much and only noticed a small drip when the car is parked for a while after a run. Any info on this would be helpful.

That cap can be removed and resealed. It has a rubber gasket. Access is difficult but it can be done. It's like a regular cap with no vent, i.e. it's a 1/4 turn to remove. There are also stops to keep it from going too far tight, which means the following caution is in order:

You may be safe since the radiator is relatively "new" in terms of heat cycles, but for anyone else reading this be aware that attempting to over tighten the cap can, and will, just break off the entire neck of the radiator. At which point you are pretty well screwed and replacing the radiator.

[Mark D]

That cap can be removed and resealed. It has a rubber gasket. Access is difficult but it can be done. It's like a regular cap with no vent, i.e. it's a 1/4 turn to remove. There are also stops to keep it from going too far tight, which means the following caution is in order:

You may be safe since the radiator is relatively "new" in terms of heat cycles, but for anyone else reading this be aware that attempting to over tighten the cap can, and will, just break off the entire neck of the radiator. At which point you are pretty well screwed and replacing the radiator.


Whenever I don't know the answer to a question like this I always think to myself "I bet Dave knows the answer to this question and then some"

:worship:

[DMC3165]

I agree thanks Dave. I was thinking the gasket may have deteriorated over time. I'm guessing there's no replacement gaskets. Is it something I might be able to find or make up at my local hardware or auto parts store?

[Mark D]

I still have my original radiator and it was leak free when I removed it. If you'd like I can pull the gasket out and mail it to you (free). You'd be replacing a 30 year old part with another 30 year old part though. I would imagine you could take the failed part with you to the hardware store and find something similar.

[DMC3165]

I still have my original radiator and it was leak free when I removed it. If you'd like I can pull the gasket out and mail it to you (free). You'd be replacing a 30 year old part with another 30 year old part though. I would imagine you could take the failed part with you to the hardware store and find something similar.

I appreciate the offer. But I agree it probably wouldn't work that well. I'll try the hardware/auto parts store option and see what I come up with. At least now I know I can take that thing off without busting it :)

[David T]

I appreciate the offer. But I agree it probably wouldn't work that well. I'll try the hardware/auto parts store option and see what I come up with. At least now I know I can take that thing off without busting it :)

Don't waste your time with the plastic radiator. The neck is probably cracked. Resealing the blanking cap won't help and besides, you can't trust the tanks to stay on after 30 years. The plastic shrinks and gets brittle because the plasticizer dries out. Do yourself (and your motor) a big favor and get a metal tanked radiator into the car. I have seen what happens when the left side tank blows off and it isn't pretty.

[DMCMW Dave]

I agree thanks Dave. I was thinking the gasket may have deteriorated over time. I'm guessing there's no replacement gaskets. Is it something I might be able to find or make up at my local hardware or auto parts store?

We actually sell a replacement cap. http://store.delorean.com/p-6295-cap-radiator.aspx

But not very often!

[DMC3165]

We actually sell a replacement cap. http://store.delorean.com/p-6295-cap-radiator.aspx

But not very often!

That's great thanks Dave! One other question I have about this radiator is how do I drain it? My copper core radiator had a regular petcock on it and that was pretty straight forward. This plastic one doesn't seem to have anything. But I did notice a circular plug with an Alan fitting? Is that the drain? It looks pretty fragile. Thanks

[LordFly]

I got plastic tanks, and still going strong! :yesss:

[David T]

I got plastic tanks, and still going strong! :yesss:

Don't try removing that plug. Pull the hose off on the bottom, right side. When bleeding the radiator be REALLY careful with that little plastic nipple on the top of the right side tank. It breaks off very easily. As for still driving around on a plastic tanked radiator, keep pushing your luck.

[DMCMW Dave]

Don't try removing that plug. Pull the hose off on the bottom, right side.

What he said.


Sent from phone

[NightFlyer]

IMHO, you're better off not messing with anything on the radiator if you can help it, except for replacing the leaking seal/cap in your case. If you want to drain it, do so via the feed and return lines in the engine bay, using regulated compressed air to push all the coolant out.

The procedure that I personally use to flush and refill the coolant system in my car can be found here:

http://dmctalk.org/showthread.php?7919-My-Delorean-VIN-3305-coming-to-Italy!!&p=125964&viewfull=1#post125964