Radiator drain plug difference

[jsrnsis]

I broke the drain plug in a 98 v70 with what I assume is it's original radiator. I was able to get it out easily with a screw extractor, but when I went to put the spare one in, it kept dripping out of the drain hole. I tightened it up a little bit past my comfort level and it kept dripping. I compared the replacement to my spare and found the original had an o ring mounted further up the plug itself, and overall slightly different design.

20231108_115738.jpg (310.67 KiB) Viewed 966 times

98 v70 that I broke is on the top. The spare one I had is on the bottom. The spare came out of a radiator from a 94 850, and looks the same as all the replacement parts I see online.

Has anyone come across this? Difference in radiator OEMs or possibly replacement vendors?

[pfmet]

I have my leaky recently replaced radiator from the 99 v70 which I’ve assumed was original. When I get home mid afternoon ish I will check and compare plugs. If it’s correct you’re welcome to it. Here’s hoping..

[pfmet]

Is your replacement o ring bad? Perhaps swap the o ring? With a little Super Lube?

[scot850]

I have seen a variety of different drain plugs and OE and aftermarket radiators are often different in terms of styles and types of drain plugs.

I'm assuming the radiator has no marking on it to identify as an OE one? The only difference that jumps to mind is that the OE radiators have a metal/brass insert in the top radiator hose outlet, where aftermarket ones don't. I think that Behr was the OE supplier back then so theirs' may have the same design still.

Now whether an early 850 is the same as a 98 V70 I can't answer that, but it is more likely it may have had a replacement.

Having looked at multiple websites for spares, the all only list the same one for Volvos for all P80's and P2 models. They all look like the replacement one you have.

Now Volvo may have changed the radiator supplier over the years so maybe yours is original for the time and what is sold now is for what is sold today, but I don't believe so. I know Nissens radiators have a different drain on some of them which looks totally different to this.

Neil.

[jsrnsis]

Is your replacement o ring bad? Perhaps swap the o ring? With a little Super Lube?

The o ring is still pliable and not crushed. It still leaked with some grease on it. It's a dripping leak but still fast enough to worry, and make a big mess on the floor.
If your spare is the same as the one I broke it would definitely be appreciated.

[jsrnsis]

I have seen a variety of different drain plugs and OE and aftermarket radiators are often different in terms of styles and types of drain plugs.

I'm assuming the radiator has no marking on it to identify as an OE one? The only difference that jumps to mind is that the OE radiators have a metal/brass insert in the top radiator hose outlet, where aftermarket ones don't. I think that Behr was the OE supplier back then so theirs' may have the same design still.

Now whether an early 850 is the same as a 98 V70 I can't answer that, but it is more likely it may have had a replacement.

Having looked at multiple websites for spares, the all only list the same one for Volvos for all P80's and P2 models. They all look like the replacement one you have.

Now Volvo may have changed the radiator supplier over the years so maybe yours is original for the time and what is sold now is for what is sold today, but I don't believe so. I know Nissens radiators have a different drain on some of them which looks totally different to this.

Neil.

The 850 radiator was replaced at 110k miles so I assume it was original to the car, it had the brass inserts.
Just checked he 98 v70, the radiator does not have the brass inserts, at least on the upper radiator hose connection. It also has the fittings for the engine oil cooler even though this is not a turbo car. I briefly looked for a makers mark but didn't see anything.

[scot850]

So it is likely an aftermarket one. Your choices are limited. Perhaps you can use JB weld and just block the drain hole in the drain plug? The only issue is the plug may still leak around the head. Perhaps a tight O' ring under the lip of the head or a fiber washer may then seal it at the head? The only other option is a replacement radiator either new or junkyard.

Like you have said the NA car is fitted with a Turbo (up to 98) radiator with the engine oil cooler. It is ok to do that in a non-turbo car it just means it is not used. Obviously the other way around is not ideal although Robert DIY suggests removing the turbo engine oil cooler and fitting a blanking plate as the the cooler thermostat is NLA.

Neil.

[pfmet]

Sorry I’m so late getting back to you. It appears my “petcock” is the same as your spare, again off what I believe to be an original radiator. Metal inserts in the inlet/outlet’s.

IMG_1812.jpeg (385.39 KiB) Viewed 910 times

[abscate]

I’ve seen three types, the OE petcock pictured above, a thick version on a Behr, and a 1/4 turn and pull down plug on Nissens. I ran Elizabeth for three years in a rubber stopper wired in when I stripped the OE petcock.

[jsrnsis]

The issue I'm having is that coolant will leak out through the hollow core, where it's supposed to drain once you loosen the petcock.
The one that I broke, had to be removed all the way to drain. I'd have to take a closer look, but it seems the middle of the 98 v70 petcock had been filled with something like a silicone or polyurethane. I'm not sure how much I'd trust this if I was to do it again with my spare, but for the time being it may have to do. I assume if I find a petcock for another car or any plastic screw with the same size and pitch thread, but a solid core, it will work.