I accidentally snapped my radiator fill plug by tightening too much. I ordered a replacement, so I thought, but it turns out to be too large to fit my hole in my radiator. The one that I am looking for is a smaller version a little less than 1/2" OD. Can someone direct me to this part number? I can't find it anywhere. I have a 1999 Discovery 1 GEMS 4.0.

 

See image for the one I am looking for.

 

https://www.ebay.com/p/Land-Rover-Ra...9435890&chn=ps

if you are talking about the plastic threaded plug on the top of the radiator get the one in the link above instead. ebay is not the only option but was the quickest to find.

 

Yeah I tried one similar to that, but it's thread is too wide for my opening. I don't know why my radiator has a smaller threaded opening. The image I attached is the plastic threaded plug that sits on top of the radiator but it's head snapped off. I'm looking for something that will work in my radiator's hole.

 

Take a picture of your radiator and the cap hole for better help. My guess is you have the wrong radiator.

You are sure it is an original Land Rover radiator? A Discovery 1 radiator should fit a Discovery 2 differential brass fill plug.ERR4686 is the only part number I know of. There is a black plastic version and an improved brass version, both shaped identically.

 

 

Some images ERR4686 is significantly larger than the plastic piece that was originally in the radiator. I bought it used and they never said that it was in a crash or a new radiator was installed so I just assumed it was stock. When I ordered the brass ERR4686 it didn't fit, so I ordered a plastic one thinking the size would be right, same size as brass one (too large). Maybe I have a different radiator, I temporarily have a bolt installed to keep some coolant in.

 

Run to the hardware store a buy a brass plug. Probably 3/8" or 1/2" npt.

 

And try get an o-ring too!

 

Be careful with the NPT plugs... They are tapered so the tighter you screw them in, the more pressure you are putting on the female thread of the radiator. Theoretically you could split it.

While it is not the best practice, if you are going to use a NPT, also use a small amount of teflon tape or you will have a devil of a time removing it.

Find the correct BSP plug (British Standard Thread -- non-tapered) and an o-ring for a long term fix.