I noticed something very odd when I first added fuel to my new XK140. Even though the fuel filler hose is over 2" in diameter the fuel needs to be added very slowly or else it will kick back up the pipe and overflow onto the fender. I can’t even set the filler nozzle on the lowest flow rate latch without this happening, so I have to squeeze the nozzle valve just slightly for a long time. My initial thought was that the previous owner had installed an anti-siphon device in the filler hose, or that the inside of the hose had separated and was blocking the fuel flow. However, when I look down the pipe it looks perfectly clear. I can see the wire from the fuel sender and there is also a small 1/4" diameter tube end at the bottom of the hose / inside top of the tank. You can see it on Plate 5-e2 on Page 239 of “XK140 Explored”. There is no curved vent tube inside the filler box, as there is in my XK120, and Viart doesn’t show one either. Has anyone else had this problem, and solved it?
I have the same issue with my 140 OTS. The tank vent is in the spring loaded gas cap (attached to the fill lid). I don’t believe there is a vent when filling. I’m not sure what the 1/4" tube does because when filling with gas that tube can’t possibly vent air from the tank.
I found that some gas pumps fill fast without any volume control. I have a slow pumping non-ethanol pump near me and on the road I just fill slowly-time to enjoy a good cigar
So from one person’s experience what I am seeing is normal. I would be interested in hearing from the many other XK140 owners to learn what the consensus is.
I would really like to learn why fuel coming out of a 1" nozzle has a hard time passing into the tank through a 2.125" diameter hose, which has 4.5 times the cross sectional area.
Me too. My guess is that the nozzle seals the downpipe to prevent fumes from escaping and this also seals the vent pipe.
Hopefully that was a joke, you’re not smoking at the gas pumps.
There has to be a vent somewhere for this very reason. What about this 1/4" tube in the top of the tank? Is it short, ending just below the top of the tank? Should there be a hose on this extending up to near the top of the fill hose? I’ve seen a little more sophisticated version of this on modern cars.
My 140 is original in that area including the fill hose and I haven’t had any problems filling the tank with premium fuel (except for the price).
With an XK140 there is a vent pipe, inside the fuel tank, that vents air back-pressure from top of tank as tank is being filled with petrol, with the vent outlet close to the top of the filler pipe… see attached pic…
When filling the tank just make sure you direct the nozzle centrally or away from the end of the vent…
If you are getting blow-back, then I would be checking that the vent pipe is not blocked, otherwise filling an XK140 should be/ and in my experience is totally straight forward and happy to normally full pump discharge… Don’t push the pump nozzle all the way in, so if fitted with a rubber splash guard (as some pump nozzles do), that the splash guard is sealing/restricting the intake pipe…
“Hopefully that was a joke, you’re not smoking at the gas pumps.”
Bob, it was a joke. I don’t even smoke.
I don’t have that small vent tube in the filler pipe as shown in Roger’s photo. I researched this earlier and Viart doesn’t show the pipe extending up the filler pipe. I had posted this question awhile ago but received no definitive responses until Roger’s photo. It appears that the tank has to be removed to correct this. It’s on my list.
As a word of caution: Moss shows that Seal rubber bulb (BD8076) is applicable to the xk140s, I believe that it is not. The xk140 vents through the spring loaded filler cap and the seal bulb will prevent the tank from venting and possible collapse.
Alan
Steven F.
You wrote: “I haven’t had any problems filling the tank with premium fuel (except for the price)”
We ALL have THAT problem!! Regardless of the make & model of the vehicle!!
Charles #677556
Are you saying the bulb is not appropriate for any XK 140? If some use it and some do not, where is the change point?
Bob,
I have a late 57 xk140 OTS. When I purchased it it had the bulb attached to the spring loaded gas cap. Every time I opened the filler door I could hear the vacuum release. I made the assumption that there is no other vent for the tank and the bulb sealed off the cap vent.
The Jaguar xk140 Spare Parts Catalog does not show the bulb seal: Filler Cap on Hinge P.148 and it does not show it in plate AJ.
I also need to correct my previous post. I thought the small vent tube extended much further up into the filler pipe, which would make sense to vent when filling. . I may have the tube ending in the tank filler extension. I need to get in there with some optics and see.
Alan
Dont know if this applies to 120/140 but been fitting a new tank on my 150fhc and noticed this tiny vent hole in the top of the filler neck…pen is pointing to it ( the white dot)…Steve
Bob,
See picture of the original Petrol Filler Door construction (1955 XK 140). No bulb, just a plain rubber ring (should be cork according the SPC) to seal the tank pipe on the XK 140 and early XK 150.
This is exactly the construction as listed in the Jaguar XK 140 SPC J.15 of July 1955. There was a (mid 1958) change-over to the “bulb” construction on the XK 150.
Bob K.
My 1956 140 has the rubber bulb to seal the filler tube and is original to the car!
Steven,
Interesting, as like I already mentioned, the XK 150 Parts Catalogue refers to the introduction of the new Rubber Cup BD.8076 + Rubber Insert BD.9278 for the cup per August 1958. Are you sure it’s original?
Bob K.
Gary’s lid looks like my 120, which has a separate vent tube in the forward inboard corner of the filler box.
All tanks need a vent of some kind. It seems like that short tube in Roger’s photo ought to extend up a few inches higher.
Is the bulb the vent on later cars?
Alan’s vacuum release could mean the vent is blocked.
Spiders have been known to make their home in vents.
Even if the tube in the tank was blocked there would be no place for the tank to vent if the bulb was installed. The bulb seals off the small vent hole in the spring loaded filler cap (for xk140). I’m not positive but I think the xk150 tanks had an additional vent so the bulb didn’t prevent the tank from venting,
Alan
I think we should all accept these XK120, XK140 and XK150 variations for what they are…
The main concern was blow back when filling, not venting, which only became an issue when Saloon owners started complaining about petrol fumes… Sealing didn’t really become effective until the August 1958 introduction of Rubber Cup/Insert, thus the vent hole for allowing air IN - to compensate for suction/vacuum in tank as fuel was used - its not a filling vent hole…
Through 1960s you got fuel caps with vacuum release/vent holes included, but when US emissions regulations controlled fuel fumes escaping, you got closed circuit fuel tank ventilation and no longer any fuel cap vent hole. Just have a look at Series 1 E-type alloy fuel caps versus same alloy fuel cap without vent hole for Series 2…
The XK120/140 cork seal is not, and is not designed to be a pressure tight seal, just something to stop petrol splashing out when spirited driving with a full tank. My pictured XK140 vent pipe is 100% correct/original as shown - and is there purely to stop splash back when filling tank with fuel …
The XK150 rubber bulb is more effective seal, thus the need for the vacuum release hole…
Best to stay with factory original XK120, XK140 and XK150 respective arrangements and accept them for what they are… if you dont want any fuel smells, or vapour emissions, buy a new F-type while you can, as regardless I still would never touch a BATTERY car even with zero fuel smells…