I recently received an "Engine Coolant Low" alarm when I was driving, and upon checking the coolant level the next morning, the coolant level was indeed low (but not by much). This was obviously a slow coolant leak, and upon investigation, the leak appeared to be coming from the coolant reservoir (where you add the coolant), and I quickly assumed that the leak was coming from this preformed coolant hose (see photo). Well, I disconnected one end of the hose from the coolant reservoir, and seeing that there was still some slack in the hose, I proceeded to cut the end of the hose off, and then reattach the hose back to the coolant reservoir. However, I didn't know that there was a tube inside that rubber hose so I couldn't complete the cut. Does anyone know what this coolant hose is called, and perhaps provide me with a part number? Thanks!

2005 Jaguar XJ8L (Coolant Hose From Coolant Reservoir)

 

If there is a plastic barb inside the pipe then that probably means it has snapped off the expansion tank. Jaguar classic parts should be able to provide part numbers. I have recently had that pipe off my car while I was replacing old hoses and there is no plastic inside.

 

Yes, the black plastic tube from the coolant expansion tank had severed all right, and that was likely the cause of the coolant leak. As you can see from the photo, there is only a 3/8" long piece of black plastic tubing that's still attached to the coolant expansion tank. I suppose that I'll have to order another coolant expansion tank, and another vent hose as well.

 

On the plus side your expansion tank is cheaper than the one on the XJR, guess how I know that. 😂

 

I went to the Jaguar dealer today, and picked up a new radiator expansion tank. They didn't have the vent hose in stock so they had to order one. Together it will run me $200. Ouch!

Afterwards, I removed the old radiator expansion tank, and installed the new one. According to the Jaguar Parts Department clerk, the vent hose should arrive on Thursday, but I will probably pick up the hose on Friday.