Fixed, By A Nose
Two Dozen Front End Tech Tips
Wayne Scraba - December 20, 2012 10:00 AM
For Your Information:
Working on a vintage automotive project (restoration or otherwise) can become downright trying — particularly if you’re forced to do something several times over just to get it right, or if you have to eventually pay someone big dollars to get it right for you.
Working on something complex like the front end of your car can present all sorts of challenges. Here, you’re dealing with three totally different systems: suspension, steering and brakes.
When it comes to the front end, there might be several ways to fix something successfully, but on other occasions, the task can be filled with plenty of trepidation. Thanks to the folks at Classic Industries (they’ve been there, done that, and they’re willing to share info), we’ve come up with dozens of shortcuts to success.
What follows are 24 of those mechanical shortcuts. Check them out. Both you and your pocketbook will be happy.
1. THE IDLER!
Worn idler arms cause front end steering shimmy and can negate the responsive “feel” the steering demonstrates. Never overlook the idler arm when it comes to steering maladies.
2. PUMP IT UP
Once you’ve replaced a set of brake pads, be sure to pump the brake pedal a couple of times. This will extend the brake caliper pistons and it will firm up the pedal.
3. RATES A REPLACEMENT
Always replace inner and outer tie rod assemblies at the same time. Replacing one worn unit will accelerate the wear rate of the pieces not replaced.
4. STORAGE PUMP
If you have a car in long-term storage, it’s a good idea to pump the brake pedal occasionally. This keeps the wheel cylinders and the caliper pistons lubricated. It also ensures the rubber cups don’t become unsealed from the respective bore walls.
5. RELAY THIS
When reassembling the steering system, it’s important to square the various bits so that the center link (relay rod) is properly oriented. Measure from the center link end of the steering box to the front pivot of the idler arm and then from the center link end of the idler arm to the point where the pitman arm bolts on. Then adjust as necessary so that everything is centered.
6. BREAK IN BRAKES
Bring the car to speed, brake once normally and then allow the pads to fully cool. The idea is to allow the pads to heat uniformly, and then cool uniformly.
7. STEERING STRAIGHT
Inspect the bolts holding the steering box to the frame. They can actually stretch and become loose. In addition, take the time to inspect welds near the steering box. If the bolts have ever become loose, it might have caused the weld to fail under the steering box at the seam of the frame.
8. ON YOUR SIDE
Some vented brake rotors are sided. The vanes must point rearward at the top of the rotor. This location allows centrifugal force to spin air outward from the center of the rotor. If the rotors are directional and you install them on the wrong side of the car, then pad life will be shortened.
9. PLAYING GAMES
Check your steering box for play. There is an adjustment nut at the top (see your vehicle service manual for proper adjustment).
10. THREAD BY NUMBERS
Before you remove the old tie rod, count the number of exposed threads. When installing the new tie rod, be sure to leave the same number of threads exposed. This will be close enough to get you to the local alignment rack.
11. FLUSHING FLUID
If you have a vintage car or truck, think a bit about the brake fluid. How old is it?
12. GREASY BUSINESS
When the time comes to lube urethane (or even conventional) swaybar bushings, there is no need to slop the grease all over the place. The idea here is to only lube the area where the bushing contacts the bar.
13. SHOCKING TRUTH
Having trouble installing shock absorber bushings? Try spraying the bushings with silicone lube. Lightly grease the shock eyelet. Use a vise to do the bull work. It’s almost as effective as a press.
14. VANISHING POINT
If you check the master cylinder level occasionally, don’t be too alarmed to find that the brake fluid is disappearing. As the brake pads wear, the caliper pistons automatically move closer to the rotors.
15. JAM PACKED
When packing wheel bearings, never jam the cap full of grease. If you do, it will just leak out and make a mess.
16. TURN THIS WAY
Why does a car sometimes pull one way in steering? All four wheels must have the same amount of rolling resistance and be square to each other and to the road surface. There cannot be any play in the steering or suspension linkage that locates the wheels.
17. BUSTED BLEEDERS
Brake bleeders always rust. That’s a given. If you’re fortunate enough to get all four loose, spend a few bucks and replace them with new ones. Some folks even use Teflon tape on the threads (with care – you really don’t want to contaminate the system). The idea behind this is to keep the threads from seizing until the next brake job.
18. ROCK HARD
If the brake pedal becomes hard and the front brakes drag, take a close look at the pushrod between the brake pedal and the master or the brake booster. Brake fluid will not be allowed to return to the master cylinder freely.
19. TILT ON THE AXIS
When you look at the side of the car, an imaginary line runs through the upper ball joint and extends through the lower. The tilt of the imaginary line is caster. If the imaginary line tilts toward the rear of the car (at the top) the car has positive caster. If the imaginary line tilts forward, the car has negative caster. Positive caster provides directional stability (the car will want to go in a straight line). Too much and it will prove difficult to steer. Negative caster reduces steering effort. Too much and the car will tend to wander down a straight line.
20. BASTER BLEEDER
If you encounter a caliper or wheel cylinder that absolutely refuses to bleed properly, you can improvise a reverse bleeder with a (large) syringe or small oven baster. Use it to pump clean brake fluid backwards into the caliper bleed screw fitting. This usually persuades air bubbles out of their hiding places.
21. REVERSE TACTICS
Yet another method of bleeding brakes consists of using a hand operated vacuum pump attached to the bleed screw. With this setup, you actually pull the fluid through the system instead of pumping it. On some cars, this is the only way to get a proper bleed.
22. CHIP RESISTANT
When working on a restoration, it’s a good idea to have the control arm bushings replaced by a competent alignment shop before painting any components. The press-off, press-on process will easily chip and scratch the control arms. Once the bushings have been installed, simply take the time to mask off the various non-painted areas and then squirt the paint.
23. DOUBLE LENGTH COILS
Coil springs found on some later model cars (for example Gen IV Camaros and Firebirds) are almost twice as long as they look. You can’t use a conventional screw-style spring compressor either. A good alternative is a spring compressor designed for use on cars equipped with MacPherson struts. By the way, when dealing with any compressed coil spring, it’s a good idea to chain it to the control arm so that it doesn’t make a quick departure in the wrong direction.
24. TUNING VARIABLES
When tuning the suspension of your car (for example, working with adjustable shocks and/or working with different rate springs), it’s a good idea to change only one variable at a time. If not, you’ll soon discover that it is difficult (and more than likely impossible) to determine what the cause and effect really is.