Hello everyone, I'm in the process of replacing the heater hoses under the s/c and decided to replace every hose while everything is removed. My question is, does the small vapor hose that's looped supposed to have a small kink to it? And what is that loop used for? I just want to be sure if its okay or if I should fix it? if you look closely, the kinks are almost squeezing the vapor hose shut. I was thinking of removing that portion and replacing it with fuel/emissions hose.

 

I would say that is not a factory bend, much less a factory kink, and has collapsed over the years from hose deterioration.
Simply put, why put a certain sized hose in to do a job then restrict it?

 

I thought the same thing but then what threw me off was the fact that it’s same same material hose as the bleeder hard hose that runs from the thermostat housing back to the expansion tank. I tried searching with no luck on what the purpose of that loop is. I know they do that for fuel system so that if a car flips it’ll will prevent something I can remember but it did have a purpose but I just can’t figure that it serves the same for this fuel vapor hose.
I think I’m going to go ahead and throw some emissions hose unless someone’s chimes and and tells me otherwise. Another weird thing is the little step down connector that joins the purge valve and that loop vapour hose is spot on which almost gets me to think it’s factory.




That vapour hose seems to be ptfe lines as well.
If anyone is looking for that step down connector let me save you a lot of time since it was near damn impossible to find it online NNA6071BA
I vacuum check that connector and it wasn’t holding not the slightest vacuum. It was dry rotted.
I know there are several variations from 01 to 03 and single canister and dual carbon canister systems. But then again jaguarclassicparts doesn’t show that loop vapour hose. Hate when this happens.

 

I would definitely say its factory, ...just old. Do you have a smoker (or know someone who does) to test it? Because almost assuredly, if you have one rotted line, you'll have more.

 

I don’t have one but I can buy one. How would I go about smoking the lines as far as what to plug and where to start the smoker? Don’t know if it would help but I think I should throw out that the car runs perfect. I am on the maintenance before it needs it. And I drive it really hard and has not given me any real big problems aside from the diff granading on me. Do you know of a nice smoker that you’d recommend?

 

Just to say, once you find the weak link, after fixing that you'll find the next weak link. A smoker isn't necessarily a need, but can be a simple helpful tool since you are in this area and can help do preventative maintenance. Its simple, pump smoke into the piping and look for it to leak and fix it. Same as a dye in the A/C system. As for a brand, if it smokes, it works....others may disagree?