Preventative maintenance

[Jammer]

Tis the season.

Have you checked in with your tow vehicle lately? Really, really checked?

- Park your tow vehicle overnight over cardboard or paper and check for leaking fluids. Correct any leaks that are found (well except maybe a rear main seal leak), paying particular attention to oil and transmission cooler line ends and power steering hoses.
- Pressure test the cooling system and cap, identify and resolve any leaks
- Remove tires, inspect both ends of both brake pads/shoes at each wheel for thickness.
- While you're there check for any sign of brake fluid or axle seal leakage
- If you have drum brakes on your tow vehicle you should pull the drums off at least once every two years to check for leaks or corroded adjuster components. If a shop does your work for you then you'll have to pay them a few bucks to do this.
- Measure tread depth and rotate tires before reinstalling (A tread depth gauge costs under $5). If the tires are at or below 5/32 they'll be no good in mud or snow and at or below 3/32 are questionable in the rain.
- Was the tire wear uneven? Any steering anomalies? Take the TV in for a front end alignment
- Check the shocks and, if equipped, steering damper.
- Does the emergency brake work? Well then what are you going to do if the transmission or transfer case fail catastrophically and you can't hold the vehicle by putting it in park?
- How about that spare? If it's on a winch, you should lower it once every year or two just to be sure you still can. Were you able to find the tools to lower it? If there's a lock, did you get the lock to unlock? (Good.) Is the jack still in the compartment or did your cousin borrow it to work on his Mustang and forget to bring it back? Now, that tire -- is it holding air? Is it the same size as the tires you're running and the proper load range? Is it less than ten years old?
- Visually check accessory drive belts for wear as indicated by missing chunks on the underside. Can you wiggle the tensioner(s) (engine off, duh) back and forth with your hand? If so then it's time for a new one. Does your belt drive speak to you? Then it's time to listen to what it's saying and replace whatever's making noise.
- If the engine starting battery is more than 4 years old, replace it. Older batteries, even if they test good, can fail without warning. If there is excessive corrosion on the terminals, replace the battery because the post seals have failed and will screw up perfectly good battery cables if you don't. The battery cables should look great; if they don't, clean them up or, if they're too far gone, replace them. (You didn't want to wait for them to quit working, did you?)
- Check all the exterior and interior lights and door switches. These are all cheap repairs to make, why give the cops a reason to pull you over or add stress because someone can't see during a trip. Are the headlight lenses all foggy? There are polishing kits and for most tow vehicles you can get cheap replacement lens and reflector assemblies from rockauto.com or Amazon.
- Check the wipers and washers. For vehicles driven regularly the performance of the wipers will drop off markedly if they are more than 6-12 months old. The online places have cheap replacements, you don't have to pay $30 a side, so buy a box of spares and leave it in your garage. I use refillable wipers and just put in new refills every 6 months whether they need it or not, costs me around $3 a side. Do the wipers go off the edge of the windshield? Then adjust them. If the washer is anemic check for leaks or a clogged nozzle or replace the pump. If you're towing with an SUV check the rear wiper and washer, too. Finally, top off the washer fluid.
- Check the rear (and if applicable, front) axle fluid. If it's low then there is a leak somewhere that should be fixed (or maybe a clogged vent). Visually inspect the condition of the oil. If it's milky then it's contaminated with water and should be drained and replaced. Opaque or silvery oil indicates age and accumulated metal filings, and replacement is a judgment call. I replace mine every 2 years whether it needs it or not, at least in the rear. Be sure to use the correct fluid for your vehicle and situation, and use synthetic fluid if it's compatible with your setup and you drive in subzero weather
- If applicable check the transfer case fluid. I drain and replace mine on a regular basis (every few years) but if you use the 4wd more sparingly you may not need to do this.
- Check the level and condition of the transmission fluid and consider the possibility of replacing the fluid and filter. The frequency with which this is necessary could be a thread of its own but at least check to see how long it's been and change it if you think it's time.
- Inspect the CV boots on vehicles that have them (fwd and most 4wd), looking for tears or missing clamps.
- If it's been more than a month or two since you used the 4wd, drive test it to be sure it engages and disengages properly.
- If your TV has zerks so you can grease the steering, suspension, and driveline, then use them. Despite the fact that vehicle manufacturers have moved away from installing zerks, they are often present on replacement components. Regular lubrication can lengthen the service life of these parts.
- Inspect the hitch receiver for any bent components, excessive wear, or broken welds
- If there is any doubt as to the state of charge of the air conditioner, check it.
- Use a checklist to be sure that any emergency items you carry are: present, unexpired, and in working order; as appropriate.
- Be sure that these items are replaced as scheduled, if appropriate: fuel filter, engine air filter, cabin air filter, spark plugs, spark plug wires, oxygen sensors
- If the check engine light is on find out why and deal with it

That's it except for oil and filter changes, which most people do too often at the expense of everything else

[JamuJoe]

Very thorough list! Nice contribution!

[Wayward]

Great list. Thanks.

One thing that is often overlooked.

Annually or not less than 2 years, have the brake fluid flushed. Most shops now have the equipment to do this at a reasonable cost even on ABS systems.

Why? I learned the hard way.

• Brake fluid is hydroscopic - it absorbs moisture from the air like a sponge.
• Reservoir diaphragms are not 100% air tight.
• Moisture in the fluid can be corrosive but the bigger problem is generally not noticeable - until the fluid gets hot. (e.g. downhill braking)
• When the fluid gets hot enough the moisture turns to steam. Steam turns the brake pedal to mush.

Proper flush method is to push fresh fluid under pressure in at the highest point (master cylinder) and cracking open each caliper bleed valve.

[Jammer]

Originally Posted by Wayward

Great list. Thanks.

One thing that is often overlooked.

Annually or not less than 2 years, have the brake fluid flushed. Most shops now have the equipment to do this at a reasonable cost even on ABS systems.

Why? I learned the hard way.

• Brake fluid is hydroscopic - it absorbs moisture from the air like a sponge.
• Reservoir diaphragms are not 100% air tight.
• Moisture in the fluid can be corrosive but the bigger problem is generally not noticeable - until the fluid gets hot. (e.g. downhill braking)
• When the fluid gets hot enough the moisture turns to steam. Steam turns the brake pedal to mush.

Proper flush method is to push fresh fluid under pressurre in at the highest point (master cylinder) and cracking open each caliper bleed valve.

Good advice, Wayward. I have done that at times, and I think it does help.

In recent years I have replaced calipers (or wheel cylinders) more aggressively, no less often than every other pad change. That has a similar effect.

[dznf0g]

In order to flush an ABS actuator, you have to activate ABS. This can only be done with a diagnostic scanner/tool effectively. It is especially important to flush the actuator as it holds fluid and does not move it unless you are in an ABS event.
If you live in a non-slippery area of the country and rarely hear/feel ABS that fluid/water will just sit there and corrode.
I would recommend that a couple times a year, you go to a snowy lot and exercise the ABS actuator. You can do it on a dirt road as well.

If you want a complete flush of fluid you will have to buy/borrow the appropriate tool. ALSO BE VERY CAREFUL when flushing your fluid that you do not let the reservoir level fall and admit air into the system. In addition to having to do extensive bleeding to get the air our of the conventional brake components, you won't get the air out of the actuator completely without the tool.

[Wayward]

Originally Posted by Jammer

In recent years I have replaced calipers (or wheel cylinders) more aggressively, no less often than every other pad change.

Yeah, we've had a few Mercedes sedans and brake flush is regular maintenance. Even after hundreds of thousands of miles we've had no caliper or master cylinder issues. The moisture in the fluid collects at the wheel caliper and in the ABS solenoids causing havoc.

[mstephens]

Nice list Jammer. I am going to print that out and try to follow as much as I can. I might try to get my service man to conduct YOUR list for me. Thanks!