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One of the things that has become clear to me of late is that many people who ordinarily enjoy their weekend tinkering are terrified of opening the fuel system.
Some of this fear and trepidation is perfectly legitimate. Gasoline (petrol) is an exceptionally hazardous substance under certain circumstances. Nonetheless, it is the essence of automotive life. If we want to drive a car with an Otto cycle engine, we must face this fact. The stuff is highly explosive; in the right concentration, the fumes can make you feel sick, and it's best to keep it off your skin. Safety around open gas lines is of paramount importance. More than one shop has been blown sky high by ignoring safety guidelines when dealing with gasoline.
While all this is true, it seems that the scary part for many Volvo owners is in having to deal with opening the fuel lines themselves. This fear and loathing is largely confined to owners whose cars have fuel injection systems. Corroded fuel injection fittings can cause great consternation when, in desperation, we use a little too much force and a line breaks, spraying gasoline everywhere. This is probably because 240 FI systems require high fuel pressure and more secure fittings than those found with in cars with carbs. I have yet to meet anyone who is afraid to change the inline fuel filter or mechanical fuel pump on her Amazon, for instance. Simply loosening hose clamps is the sort of thing that the rank beginner can manage without a fuss. 1800, 140 and 164 Volvos equipped with D-Jetronic FI are also put together largely with hose clamps and rubber fuel injection line, making them somewhat easier to work on, in this respect.
Just recently, I heard one fellow, otherwise an avid shadetree mechanic, state that he would sooner send a car to Valhalla than change the FI fuel filter. Perhaps he was kidding, but he is hardly alone in his sentiments.
Still, Mother Volvo recommends the fuel filter be changed at 15,000 mile intervals, which roughly translates to once a year whether you need it or not. Loosening the fasteners annually ought to be often enough to convince most of them that they are not an integral part of the object they are threaded into. As is all too often the case with, for instance, brake bleeders, the fear of breaking parts can cause people to neglect regular maintenance until the situation turns critical. Then, of course, the probability of breaking something is increased exponentially.
Throughout the fuel injection system on engines equipped with Bosch K-Jetronic and LH-Jetronic injection Volvo began using hard plastic lines. Often covered with rubber for protection, these high-pressure fuel lines look a lot like common rubber fuel lines -- without the hose clamps. Whether they terminate at a banjo fitting or at a swivel, this hard plastic is joined at the factory onto a barbed fitting, and if cut, they are difficult to reconnect safely. They do have a certain amount of give to them and will take a fair amount of twisting force without crimping. This can really be helpful in some situations. Sometimes ancient swivels are frozen in time and unwilling to respond, at first. Be careful, though, not to overdo it. If the lines are crimped or twisted hard, they will almost inevitably develop leaks and need to be replaced.
With fuel lines in particular and plastic parts in general, the use of heat, such as a propane torch, is contra-indicated. My most important tools of choice for persuading frozen fittings are patience and penetrating oil. My personal favorite rust buster is Parker Brother's "PB B'laster," but others swear by Wurth "Rost-off" or "Kroil." Forget WD-40 for this operation. It is best used for its original application as an industrial Wire Drier (hence the WD). Patience is really important, too, and you will have to supply this for yourself.
As for other tools, in some places you will find a flare wrench is ideal for this work. A flare wrench is essentially a box wrench with an opening to allow you to slip it over the line. Unlike an open-end wrench, a flare wrench offers more support for the swivel fitting and will help to keep you from rounding off the points of the hex. There are a few places in the system where this won't work, and there an open-end wrench will have to suffice. For the large hex on the ends of most FI fuel filters found on Volvos, a thin crescent or adjustable wrench will serve well. In the case of lines with a swivel that needs to be opened, I use a pair of flare or open-end wrenches that are positioned at an angle to one another on the fittings. This way, I can squeeze the two handles together and turn the fittings in the right direction.
This is not a good place to use excess force. Instead, try going in the opposite direction, ever so gently, and then back. Again, and again This motion, with the use of more penetrating oil and still more patience will eventually lead the fitting down the road to loose behavior which -- at least in this case -- is a very good thing. Whether the part you are trying to remove is a fuel filter or perhaps a fuel pump, you may want to leave it firmly attached to the mount in order to give it support while you loosen the hardware. Most banjo bolts can best be loosened with a socket, but hold the part it's threaded into firmly. Be aware that the use of water pump pliers can crush a fuel filter, so be gentle, but firm.
One of the design changes made in the early '80s 240 model, with the change to LH-Jetronic injection, was to relocate the fuel filter underneath the car on the same pan as the fuel pump where the fuel accumulator used to be found.
In order to access the pump or filter, you'll have to raise the car and drop the mounting bracket. To do this, loosen only the two front bolts and let the bracket swing down on the steel strap bolted to the back. While you're under there, inspect the rest of the fuel lines. The steel lines held to the body of the car are subject to corrosion. Another under-the-car fuel line swivel on most 240s is above the axle fitting that goes to the in-tank fuel pump. Once again, you'll have to get under the car to get at it.
Always use new copper crush washers (gaskets) when installing new components. If this is impossible for whatever reason, you can re-anneal the washers by heating them red hot -- I do this with the washers hanging on a bolt which is held with pliers or in a vice. Allow them to cool naturally and clean off any oxidation that has formed. Do this far away from any open fuel lines or spilled fuel. Be sure all fittings are tight and secure before running the fuel pump. Make sure you have all the parts you will need gathered before you open the fuel system.
To insure safety around open fuel lines, here are a few things to keep in mind:
If you are careful and patient, working with your fuel system should not pose any great danger nor should it be beyond the realm of backyard mechanics. Just follow the rules and remember that this is another case to which Hofstadter's Law applies. You may never have heard of it, but if you have ever worked on your own car, you have certainly been subject to it. Hofstadter's Law: "The time and effort required to complete a project are always more than you expect, even when you take into account Hofstadter's Law."