Jim’s Blog: Four Overlooked Old Car Fixes

If you drive an old car on a regular basis, you’ve likely had to come to terms with the fact that it’s just harder to use than a modern car. Brakes, lights, wipers, and suspension systems just weren’t as good 40 years ago, right? Right. But that’s not the whole story. The age of the parts — and how much they’ve worn — is a big factor in how your car drives.

Full frame-off restored cars tend to have all-new components, but there are also a lot of cars out there that were freshened up over the years rather than completely torn down. And those cars have parts that are likely functioning well past their expected lifespans. The net result is a car that is already old and functioning with overlooked and worn-out bits and pieces, and the driver probably doesn’t even know about them. “It’s just how these old cars were,” is something I hear a lot.

So, here’s a quick list of four overlooked items that you might want to address in your own old car — especially if you’ve never had the car torn down to the frame and restored.

1. Generator/Alternator

Say you’re parked at a stoplight in a rainstorm in your original ’60s GM pickup. All of a sudden, that old 55-amp alternator has to power brake lights, headlights, wipers, defroster, radio and blinkers. It’s all running at once, and everything runs slow — the wipers creep across the windshield, and the turn signal flashes slow and dim. Not ideal in bad visibility conditions. And the problem gets even worse with modern powered additions — like stereo systems — that the original charging system was never designed to run.

You can replace the alternator and regulator with OE-style fresh units to try to boost output, and depending on your needs, that might solve the problem. Even better, a modern SI-style 70+ amp unit with internal regulator can help keep everything functioning the way it was designed to work without looking out of place under the hood. Swapping over is easy with a plug-and-play regulator conversion adapter, which bypasses the external regulator while still using your original wiring harness — no hacking required. They’re offered from companies like Classic Industries. Ford and Mopar units are also available from other parts suppliers. No more slow-moving or dim accessories, regardless of the situation.

2. Grounds

This goes hand-in-hand with the alternator. Your car had a bunch of engine, chassis, and body grounds from the factory, and they tend to get less effective as time goes on, thanks to rust and corrosion. Those grounds are small, but they complete the circuit for all the electrical systems in your car — so they’re important.

Bad grounds can cause all sorts of weird electrical problems, such as dim headlights, hard starting, inoperative accessories, and brake lights that stay on all the time (until you hit the brakes — then they go out).

And the weird part about grounds is that problems with them can manifest at any time, regardless of when the ground actually went bad. When I took the rear bumper off my truck to paint it, the brake and taillights, mounted up in the bed, quit working. Now, there were no wires attached to the bumper when I took it apart, so on the surface this made no sense. I tore my hair out for the better part of an afternoon trying to figure out what happened, until I realized that there were no grounds from the bed of my truck to the chassis, as there should have been from the factory — the bumper apparently touched the body somewhere and was bolted to the frame, so it served as the ground to complete the circuit for all the power to the lights in the bed. Who knows when the actual grounds went away, or who removed them?

So, it pays to check all the grounds you can find — take them apart and clean the mating surfaces, and if you see where one is missing, like from the body to the frame, or from the engine block to the frame, or from the engine block to the body, add one. It’s simple and quick to do, and it’ll save you trouble later.

3. Power Brake Booster

If your classic car has power brakes, you have a power brake booster. And it’s likely never been off the car.

These boosters, mounted to the firewall behind the brake master cylinder, operate off engine vacuum. They’re sealed units and they don’t require much maintenance, but they can start to leak slowly over the years, and that can cause rough engine idle and hard braking. They’re easy for a mechanic to check — does it hold vacuum or not? But buying a rebuilt unit, or having your original rebuilt, is cheap insurance — at the very least, you’ll know all is well with the system. If you’ve been living with a leaky one for years, a new or rebuilt one will make a big difference in how your car runs and stops.

4. Body Mounts

If you have a body-on-frame car, as many were back in the ’60s, you have rubber body mounts. And unless you’ve done a body-off resto, they’re shot.

Body mounts are supposed to absorb road noise and vibration, but over time they dry out and turn hard, which means they can’t do the job effectively any more. The result can be increased road noise and vibration. The change happens gradually, so you might not even notice the ride quality or noise level deteriorating.

Most restoration houses stock replacement rubber body mounts, and while swapping them out isn’t especially easy (although the process is simple), the net result is worth it. You’ll need some bolt penetrant, a couple of jacks, and some big sockets, extensions, and ratchets. Or you can just have your shop take care of it, which I recommend — the body bolts have not been loose since your car was built, so they won’t want to come out, and stripping or breaking one is bad news.

Regardless of whether or not you tackle these items as DIY projects, it’s smart to check into each of them. If you’re going to be putting miles on your car, these kinds of fixes help make the experience fun rather than stressful.