Fuel-filler door latch release cable seizing up?

Could be the rust is at the interior release lever or at that end of the cable. Remove the trim or cover so you can get at the metal pivoting bracket underneath and where the cable attaches. Use PB Blaster on that metal lever to see if the mechanism frees up.

Is the cable rusted so it doesn't move freely? There are tools that let you lube a cable by clamping onto the end of the cable and using the pressure in the spray can to push lube into the cable.

However, that pressure isn't high so it is not going to push the lube all the way along the gas door cable unless you do it from both ends. You can only hope that the lube reaches the rusty area. Also, you need to get at both ends of the cable which can be a bear: probably not bad at the interior release lever end but you'll have to get through the trim to get at the mechanism at the gas door. If lubing the cable doesn't work, well, you're going to have to remove all those panels, anyway, to replace the entire cable.

Even if you lube the cable, rust expands. You'll loosen the rust but the expansion of the metal due to rusting might prevent smooth operation. I would NEVER use WD-40. That gets sticky and attracts dust and dirt. Use chain or teflon lube but I'd probably start with PB Blaster for breaking the rust and then use chain lube.

If you don't really need an interior release but just want to prevent someone from siphoning out your gas (although a big flat blade screwdriver will defeat a little plastic pin to hold the door shut), you could use a locking cap. Disable the gas door release (e.g., snip off the plastic pin that locks the door in place) and use white Gorilla glue with ceramic magnets (might need to layer the magnets in some spots) to hold down the gas door.

(Presumably your door is still on its hinge so you only need to add the magnets and disable the release.) Or is the problem the gas door doesn't pop open when you lift the release lever on the inside of the car? If so, maybe the spring plate is too bent and not applying enough pressure to push the gas door open.

Op 9-6-2018 om 07:44 schreef Yousuf Khan:

I have had a 18 year old Impreza and a 19 year old VIVIO which did not have that problem. So it's not an 'age' thing but clearly the cable contracts moisture somewhere; irrepairable. I would replace it.

Gerard

No, it's not an age thing, but it is a climate thing, since I live in Canada, and they use road salt all winter long.

Yousuf Khan

Never heard of PB Blaster. Judging from the video, it seems to be being used for throttle cables, seems a little overkill just for a fuel-door cable, afterall I'm not expecting millisecond responsiveness out of the fuel-door cable.

Just used the WD-40, just a little while ago. It seems to have worked beautifully. It's moving nearly freely now again, did nearly a dozen up and down movements on it, and it started getting looser and looser after each movement. So it seems to be fixed for now, at least until next winter when more salt gets introduced.

Yousuf Khan

The rounded top cans usually do not come with a straw to direct the spray. The squared top cans come with a straw, so you can get the lube into small or recessed spots (and the straw might be usable with the cable oiler tool that I mentioned to get the lube along the cable). It is a high-temperature lube, so it's good for lubing up cables or parts near the exhaust or other high-temp locales, plus it's a penetrant and works pretty well to unsieze rusty metal parts.

I thought you claimed you knew the *cable* going to the gas door was rusted. PB Blaster is pretty good at breaking up the rust. It is a penetrating oil. I've used it on cables, like bicycle brake cables which also don't need millisecond response, either, along with the hood release cable and latch, door hinges, or anywhere there might be rust (now or later) where there is metal-to-metal contact, like inside the wire cables used in cars and bicycles. I wouldn't use it, say, on a bicycle chain since that needs something like chain, teflon, or moby oil. Although a high-temperature lube, it is too thin for constant high-friction use, like a chainsaw. The right lube for the job, and WD-40 is really only good for cleaning (it doesn't affect rust), not for long-term protecting.

Likely the gas door cable is inside a sheath which is coiled metal wire surrounded by vinyl or other plastic. That is metal-to-metal wear: stranded wire cable against coiled wire sheath. Don't know where you are, so maybe PB Blaster isn't available there, but you should be able to find another penetrant lubricant, like what gets used on rusty bolts and nuts. I like the high-temp penetrating oils so, for example, I could use a torch on a nut to expand it and help break the rust along with the penetrating oil. In the USA, PB Blaster is at Menards, Lowes, Walmart, Fleetfarm, car parts stores, and lots of other places.

Although you think it's the cable, and mentioned before, I'd first check the release lever in the interior of the car. If it is on the floor then it can get wet from rain or snow on your shoes along with any salt used on the roads to speed up the corrosion. The release lever has a pivot that you can use the penetrant lube plus gets you at that end of the cable without a ton of trim removal. Quite often not-so-fastidious car owners let dirt, salt-laden snow, and water pile up in their carpet and the carpet is around the release lever (unless it is a dash-mounted lever). In fact, I've seen there a combo lever (pull up for trunk release, push down for gas door) was rusty at that end of the cable causing the plastic end of the cable to break that holds the cable into the bracket for the lever. Pulling works to open the trunk but pushing results in pushing both the cable and sheath backward so the gas door's latch pin sees no effective movement of the cable relative to the sheath.

A shot of penetrating lube around the pin that holds the gas door is probably a good spot, too, as well as the gas door's hinges (since the objective is for the door to pop out when the pin retracts).

WD-40 will displace water but won't keep it out. It gets sticky over time and why it's a bad choice for door hinges or any moving metal parts. When it gets sticky, it attracts dust and dirt. Use it on hinges and they will get dirt streaks and start squeaking again. It's great when you want to *clean* something but poor when relied upon as a lasting lubricant. The dirt that sticks to the WD-40 attacts water (and any salt in the water) again resulting in a recurring problem when using that lube.

Where'd you use the WD-40 that fixed the problem (for now)?

WD-40 WD = Water Displacement

40 = Number of formulae testing before settling on this formula.

WD-40 is good at water displacement, not at water resistance since it is not a true lubricant. It is also good for breaking rust but you'll need to clean the parts to apply real lube (so you'd have to pull out the stranded cable from the sheath, clean both (e.g., brake spray), and apply real lube; else, you'll have the same or worse problem later because the mineral oil gets sticky.

Since you don't want to pull apart a cable to use WD-40 to remove rust and then reassemble the cable -- which assume that you can disassemble the cable which is unlikely -- you want a penetrating oil that actually lubricates when left behind, like after injecting into a cable.

WD-40 works better than PB Blaster (and Gumout Freeze Out) to unsieze rusted nuts and bolts. That's not what you are trying to do. After breaking the rust, you need to clean off the WD-40 to use a real lube and that's not going to happen with a cable (well, some you can pull apart, like a bicycle brake cable since one end doesn't have a crimped lug on the end). Similarly, Gumout doesn't leave anything behind so you will add lube. Some swear by a 50-50 mix of ATF (automatic transmission fluid) and acetone to break rusted nuts from rusted bolts; however, I suspect the ATF is the main player. Obviously for nuts and bolts you wouldn't be lubing them after, so cleaning off the WD-40 or not having any Gumout Freeze Out left behind is the next step before putting them back together (perhaps with some anti-sieze compound). If you cannot follow up with a cleanup after using WD-40, you want to try adding a real lube. You don't want mineral oil as the lube.

Of course, no penetrating oil is going to work if it cannot penetrate. A severe rusted spot in the cable would dam up any penetrating oil from getting further. Sometimes chemicals just won't salvage a part and you need a nut breaker, cable replacement, or a new part. Where is rust means the metal has swelled, so there's permanent damage to the metal. Swelling is what causes the siezing since rust is by itself pretty fragile.