It should look like part #4 in this diagram.

Part no. CBC7714 | Pressure control valve parts from Jaguar Classic Parts UK

 

I recently read the problems that a few members have had with the ac delco rochester vallve causing their fuel tanks to implode. I have not had this problem and removed my rochester valve in order to take a look at the orientation because I may have installed it backwards as some members have done. I found that the valve was clearly marked with VAC, TANK and CAN, on its connections and my tank was fine as I just connected each hose to its proper location. Sorry that some members ran into problems, maybe there new valves were not clearly marked.

 

Check this out, I have a 1997 XJ6L with the dual canister system. It looks as though, my car doesn't have one of these valves!
Twin Carbon Canister-4.0 Litre-Usa - Parts For XJ Series from (V)720125 to (V)812255 (X300) | Jaguar Classic Parts UK

vs the single system

Carbon Canister-3.2/4.0/6.0 Litre-Single System - Parts For XJ Series from (V)720125 to (V)812255 (X300) | Jaguar Classic Parts UK

 

That is interesting, my 97 XJR has the single canister system that requires the valve. I wonder why some had the dual canister systems... perhaps California emissions?

.

 

I am on my second X300, a 97 XJR6 now, and both the previous one and this one's fuel tanks were under significant pressure, same goes for the 91 XJS I also previously owned. I figured it was not a real problem, just another Jag curiosity. Just purchased one of these valves via carparts.com. Very much looking forward to not having fuel droplets blow out from cap every time I stop for refueling.

 

You must have purchased the last one. "No longer available for sale".

 

So I've had my cap vent pressure just a handful of times, although pretty impressive, usually when the tank is low on fuel and has been sitting for a while. I've also had a few times where trying to fill the tank the pump seems overly sensitive and clicks off constantly. But this too is rare.

Does that indicate this valve ought to be changed?

BTW, the Cbc7714 seems to still be available from several vendors though may indeed be discontinued, but is $80-100. So not cheap.

.

 

I have an AC Delco part I can sell. My car, a 1997 California XJL, doesn't have this part it turns out. PM me if interested $35 shipped USPS Priority

 

Just wanted to revive this thread and check in with everyone to see how the replacement valves were holding up? I have a 1995 XJ6 and been having gas cap pressure for the past year and finally going to do something about it by replacing the valve. Just wanting to see if the Delco part is proving reliable over long term!?

 

Sure is. It's fine. I don't believe anyone has any issues with it.

 

Hi, the valve fitted on our 96 XJR has the part number 17089101. Its a Rochester part. Since day 1 this car has been terrible to fill with fuel. The process can take up to 15 minutes. Is this the right part or should it be marked as 7714 as the posts seem to describe. Might sound a silly question but I see a seller of a supposedly genuine part has the same number if you look closely. Our car doesn't smell of fuel and everything works fine...i just would love to get rid of the filling problem.
Thanks

 

There is a Delco replacement and as long as it takes to test the original might as well replace it

The pic and # are on another computer that I can't get to for a couple of days

It could also be hooked up backwards , but it's not something you want to play with risking collapsing the fuel tank

You may have to inspect your tank to see that it has not already collapsed in some manor

Do you have the 1 vapor canister system or 2 , one on each left and right ?

The 2 canister system does not take a Rochester Valve , See page 60

www.jagrepair.com/images/Training Guides/801S - 2000.pdf

 

Hi, the training document was very informative...just to make sure i understood the logic.
I don't think there is any tank damage. Even though we get an impressive "whoosh" when the filler cap is removed, I have never heard "oil canning" noise which would indicate vacuum I would have thought? Our problem, is probably pressure inside the tank which activates ( I presume) the overfill sensor in the bowser nozzle. Strangely if the driveway slopes down away from the bowser so the fuel tank is "elevated" it is usually possible to fill the tank, albeit slowly. This frustrating scenario is not consistent, even with an identical bowser; week to week.
We don't have the enhanced system, thus only one canister.
Thanks again for the response.

 

Thinking

 

Whoosh sound is usually solved by replacing the Rochester Valve. Its an easy and inexpensive fix.

The problem filling the tank is probably a different issue. I would suspect that a fuel vent is clogged.

Look here:
​​​​​​https://parts.jaguarlandroverclassic.../brand/jaguar/

That tube connecting the top of the tank, back to the filler neck is what should vent air out as you fill your tank. If that is clogged, I can see having a fillup problem. Would be great if you could shove some compressed air in there....