Planning a road trip? These spare parts could save you from being stranded

Last week we talked about which tools you should consider bringing with you when you venture out in your vintage car. I proffered my opinion that, even if I was just tooling around on a Sunday morning to buy milk or a newspaper (wait, do people still do that?), experience has taught me to bring along a basic set of tools.

Obviously, when embarking on a major road trip, the size and weight of the tool selection increases. In a perfect world, with a perfectly-maintained car, you wouldn’t need to use a single one of them.

The same is true when it comes to spare parts. Hopefully, you won’t need what you bring, but you’re virtually guaranteed that the opposite is true, and you’ll likely rue whatever you left behind in the garage.

A few months ago, I did a series about “The Big Six”—the six things that are most likely to send a vintage car into the breakdown lane. Those things include the ignition system, fuel delivery system, cooling system, charging system, belts, and ball joints. It should come as no surprise then that the spare parts you should bring along pretty much mirror The Big Six.

Before I go through the parts list, I’d like to point out that some people believe if your car is well-maintained, you should never have to crack the trunk and use the tools or parts you’ve brought with you. In other words, if you feel the need to travel with a spare water pump, for example, you obviously don’t trust the water pump that’s installed. So why not just replace it in the comfort and safety of your garage and be done with it, instead of waiting for it to crap out? You know, of course, that since you were an idiot and didn’t replace it at home, karma will surely cause the failure to occur on the approach to Tappan Zee Bridge, right?

It’s a fair question. And the answer is: Every owner has to find that point on the preventative maintenance curve that they’re comfortable with. Too far to the left side of the curve and you’re mechanically restoring things that ain’t broke. Too far to the right and you’re driving with known problems and actively tempting fate. The way I look at, cars are not biological systems. They don’t heal. Any known problem will get worse over the course of driving thousands of miles. You’re a fool if, before taking a long trip, you don’t fix things that you know need attention.

But the gray area is pretty big. I used to pre-emptively replace pretty much the entire ignition, cooling, and charging system, much of the fuel delivery system (fuel pump, filters, and hoses), and all the belts on any vintage car that I planned to distance-drive to events. Once I even pre-emptively changed a head gasket on a 1972 BMW 2002tii before a 3,000-mile road trip. There’s no question that the peace of mind that comes with this kind of prophylactic maintenance is incredible. However, over time, I’ve backed off a bit. I have more accumulated wisdom, my budget is often tighter, and I’ve seen globalization often cause new OEM parts to be of lower quality than those I’m removing.

Here’s my recommendation: On a vintage car with points-based mechanically-advanced ignition, the points and condenser are frequently the culprits, and they’re often swapped on the roadside. On a drive of any length, I bring a spare set, even if the car has been converted to electronic ignition (this handles the unlikely situation that the electronic ignition module dies). If the trip is more than an hour or so, I’ll also bring a set of plugs. On a long trip, I’ll typically pack a coil, cap, and rotor, but the failure rate of these components is much lower. I bring them mainly so I won’t feel like an idiot if my distributor cap cracks and I don’t have a spare with me. On a post-mid-’70s car with electronic ignition, especially anything newer than an early-’80s car with digital engine management, I typically won’t bring any ignition parts. Experience has shown these ignition systems to be very reliable, at least on the vintage BMWs that comprise most of my passion.

Points, condenser, and plugs are must-bring items. The rest just help make you feel invincible.
Points, condenser, and plugs are must-bring items. The rest just help make you feel invincible

I’ve found that the second-most likely part to die and leave me stranded is the fuel pump. I feel pretty exposed heading off on a long trip in a vintage car if I suspect that the fuel pump hasn’t been changed since the Carter administration. Mechanical fuel pumps tend to experience failure slowly; as the diaphragm stretches, they pump less and less gas, and eventually can’t fill the carburetor’s float bowl faster than the engine is drawing fuel out of it (the old saying is, “If the car feels like it’s running out of gas, it usually is”). In contrast, electric fuel pumps often fail suddenly, generally due to rust or sediment from the gas tank getting into the pump. Sometimes, smacking the pump (or the bottom of the gas tank if the pump is in the tank) will temporarily free it, but that’s often your one and only warning: Don’t shut the car off, drive it somewhere safe, and change the pump.

When I buy a car or ready it for a long trip, I’ll do a full fuel system sort-out, which involves inspecting every rubber fuel line and replacing them all if they look original, replacing every fuel filter, cleaning every fuel screen, and removing the electrical fuel pump and tapping it out on a paper towel. If the fuel pump is rust-contaminated, I replace it. If it’s not, as long as it isn’t noisy, usually I’ll leave it. But I will bring a new or used spare. The fact that the fuel pump in my mechanically fuel-injected 2002tiis can be replaced with the same electric fuel pump as some of my ’70s and ’80s BMWs means that I can have one spare electric fuel pump that can be used in various cars.

Typically I’ll also bring a length of rubber fuel line several feet long, which I can use to replace the longest line on the car. And if I’m driving a BMW 2002tii, I’ll bring a used spare set of the plastic fuel lines running between the mechanical injection pump and the injectors, since if one of these lets go, you’re not going anywhere until it’s replaced.

Fuel pump and a length of fuel line
Fuel pump and a length of fuel line

On the cooling system side, as I described in “The Big Six” series, I visually inspect and squeeze the cooling hoses. If they’re not soft and pillowy or super hard and cracking, I’ll often leave them. I rock the mechanical cooling fan to test the water pump bearings. If I don’t feel obvious play, I often leave the water pump alone. Depending on the car, water pump failures can be “soft” (they begin leaking a little coolant) or “hard” (the bearing catastrophically fails or the impeller shatters). But, when leaving on a big road trip, I make it a point to bring along a spare water pump, even if it’s used, and a gasket, along with (if possible) a spare for every single cooling hose. The upper and lower radiator hoses are often the ones that shred, but (keeping Murphy’s Law in mind) don’t bring replacements for only those two hoses.

Like the fuel pump, I’m fortunate that the M30 engines in my three six-cylinder BMWs all take the same water pump, so I can use a common spare.

Water pump, gasket, and every cooling hose
Water pump, gasket, and every cooling hose

I don’t know anyone who travels with a spare radiator. You need to inspect the condition of your before you hit the road and live with your decision.

Charging system problems are also pretty common. Both the alternator and regulator can and do go bad. The result is that the battery doesn’t get charged, so it slowly drains while you’re driving until it can’t fire the ignition or spin the fuel pump. I used to prophylactically replace alternators prior to long trips, but the rebuilds from Internet sources, including the official Bosch rebuilds, have such a spotty reputation that I’m not comfortable with. The good news is that vintage cars have pretty modest amperage needs; you can probably drive all day on a fully charged battery. If the charging system fails and you can’t procure the parts on the road, you can buy a battery and two chargers, swap the battery when you need to, and recharge both batteries in your hotel room at night. On longer drives, I’ll bring a spare alternator and regulator that I know are good to go. More often than not, they wind up being swapped into someone else’s car.

Yes, on long trips, I often take both an alternator and a regulator
Yes, on long trips, I often take both an alternator and a regulator

Belts are simple: Bring a spare for whichever one runs the water pump. You’re an idiot if you don’t. Yes, it’s better if you changed the belt recently. But bring a spare anyway. If you have an oddball, mechanically fuel-injected car like a BMW 2002tii with its belt-driven Kugelfischer injection pump, or an Alfa with its Spica pump, bring a spare belt for the pump. Thinking you can buy one buy one at the nearest Autozone is a sucker’s bet. Yes, there are often bushings and tensioners and idler pulleys that are needed to keep the belt tight and aligned. You should check those before a long trip. Again, bring the belt anyway.

It’s a spare belt. Don’t overthink it. Pack it
It’s a spare belt. Don’t overthink it. Pack it

No, I don’t travel with spare ball joints. Those are something you figure out in your garage before you leave.

That’s pretty much it. Oh—a coat hanger. Bring one with you in case one of your rubber exhaust hangers breaks.

Also, on long trips I travel with a head gasket set. It’s not that I expect the head gasket to blow and I’ll have to replace it in a parking lot. If I truly expected that, I’d change it before the trip. So while I’m not advising you to pack one, I feel good when I do.

The head gasket set—the sure sign you’ve gone over the edge
The head gasket set—the sure sign you’ve gone over the edge

Plus, if I left the head gasket set in my garage, I’m convinced that its presence there would cause parts in my car to fail. The universe is a zero-sum automotive game.


Rob Siegel has been writing the column The Hack Mechanic™ for BMW CCA Roundel Magazine for 30 years. His new book, Ran When Parked: How I Road-Tripped a Decade-Dead BMW 2002tii a Thousand Miles Back Home, and How You Can, Too, is available here on Amazon. In addition, he is the author of Memoirs of a Hack Mechanic and The Hack MechanicGuide to European Automotive Electrical Systems. Both are available from Bentley Publishers and Amazon. Or you can order personally inscribed copies through Rob’s website: