A while back I wrote about my young cousin Mitch and his love of 4WDing, especially mud driving. At the time his engine was suffering from overheating and since then his Hilux has encountered other issues, typical of 4WDs that have travelled their fair share of tortured kilometres.
Most 4WDs perform seamlessly over many years and kilometres; however, a few consumable components will inevitably weather and wear during this process. Tyres, batteries, fluids and brakes all suffer as the odometer turns.
Just how much they suffer comes down to just how well you look after them. A lack of maintenance over endless years of punishment will, you guessed it, wear them down prematurely. So it’s always a good idea to check these overlooked components when you're readying your 4WD for its next trip.
This time around Mitchell mentioned he was having issues with the Hilux’s front disc brakes and wheel bearings. This came as no surprise, given he’d been dragging it through pools of everpresent mud, camping trip after camping trip. We thought it best to address the Toyota’s concerns quickly. It’s a pretty easy process and I’ll run you through it here.
With any 4WD work, my main priorities – apart from remedying the issue at hand – are proper preparation, using the right parts and adhering to safety principles. It’s not hard to conform and in the long term it’s more rewarding.
There are times when third-party suppliers are a good option for saving a few coins but I do try to use OEM spares for the most part. OEM parts can be expensive, so shop around and don’t be afraid to explore avenues outside of your local dealership. Even looking overseas can be very rewarding, especially if you own a globally circulated brand like Toyota, Land Rover or Jeep, for example. Luckily Mitch had sourced quality parts locally.
THE TOOLS REQUIRED
To complete this job, we needed just some basic hand tools and some extras such as supports, containers, lubricants/cleaners and assorted rags.
A good hydraulic lifting jack is indispensable. Ignore those tiny $30 floor jacks (and your vehicle’s jack) and go for a unit that has a maximum lift of around 450-500mm. Good two to three tonne examples can be found around the $120-180 mark and offer stable lifting of heavy 4WDs.
But I never rely on the floor jack alone (especially if placing any part of my body under the vehicle). I always use a pair of 2T car jack stands, that cost around $40 a pair, to complement the floor jack. This ensures a sturdy platform.
A set of 3/8 sockets in 10, 12, 14, 17 and 54mm, assorted spanners, cold chisel, old large screw driver, hammers and most importantly a torque wrench is all you are likely to need, along with some brake cleaner and bearing grease. A bucket will help prevent spillage and unnecessary cleaning too.
REMOVING THE WHEELS TO GET ACCESS
After wheel chocking the rear wheels and leaving the transmission in gear, we loosened the wheel lugs just a full turn before jacking up the vehicle. Once we fully jacked the front end (read your user manual to find the correct jacking points), we placed the aforementioned stands to support the axle and then removed both wheels. It was now apparent that the Hilux had seen its share of mud, so we cleaned away as much as we could and continued.
A vehicle of 25+ years wasn’t going to be without a fair deterioration of its brake and hub components. So rotors, disc pads and bearings were on the agenda to be addressed. It’s imperative to get the correct matching replacements. If in doubt, take samples to your favourite auto parts supplier to ensure a correct fit. A set of quality slotted rotors and disc pads set Mitch back around $250. While at it, we decided to replace the outer and inner bearings, racers and inner seal, which cost $140 a pair. During the process we even decided to run back to Repco and replace the wheel studs for $3.40 each.
REMOVING THE HUB AND DISC ROTOR ASSEMBLY
This older 4WD, with manual free-wheeling hubs, required more steps than a modern 4WD with auto-locking hubs. The first step was to remove the old disc pads. After removing the pad’s retaining clip and pins, we used an old screwdriver to part them and then slid the pads out. If you are undertaking this task yourself, be careful as there may be some retaining clips attached to the pads which you’ll need to reuse when putting in the new pads (depending on model vehicle).
Replacing the disc rotor requires dissembling and removing of the hub assembly (modern 4WDs with auto hubs can skip this bit as the rotor can just slide off). Using a 10mm socket we undid the six bolts that hold the locking hub cover, and then set the cover aside. Next we removed the inner circlip, easily done using a circlip tool or just a little creative ingenuity.
Then we removed the hub body’s six bolts, along with spring washers, using a 12mm socket. With a few enthusiastic hammer taps along the hub’s body, we persuaded it to separate. There are also some cone washers that will need to be retained for reassembly. This now better exposed the inside of the hub’s workings.
There is an odd shaped locking washer (that prevents the nuts loosening) which needs its tabs straightened using a screw driver. Once the tabs were straightened we easily unscrewed the large bearing retaining nut by hand as it was quite loose; if you encounter a tighter one, you can use a 54mm socket. Then we prised out the said locking washer and undid the inner adjustment nut using the same socket, which was them followed with the thrush washer.
Using a 17mm socket, we undid the two bolts supporting the brake caliper and carefully slid the caliper just off the rotor, as there is little brake line flexibility. Suspending the caliper we slowly prised the whole hub/rotor assembly away, taking care to catch the outer bearing that fell out. Once cleared we temporarily re-bolted the caliper in place.
SEPARATING THE HUB FROM THE ROTOR
To separate the rotor from the hub assembly, we first undid two bolts on the inner face of the rotor using a 14mm socket. Then we drove out the six wheel studs with some encouraging hammer hits. Once all studs are detached, the hub assembly will part from the disc rotor, again with some enthusiastic hammer persuasion.
At this point it’s worth cleaning the area and surfaces to ensure maximum longevity and ease of reassembly. Once cleaned we positioned the new rotor and reused the two 14mm bolts with a dab of Loctite. Using a whacking big hammer we forced in the six new wheel studs, ensuring they were flush with the surface.
CHANGING THE WHEEL BEARINGS
The final piece of the puzzle is changing the inner and outer wheel bearings and their corresponding racers (a racer is a cone shaped ring that supports a bearing). Holding the hub assembly and using a heavy hammer and cold chisel we systematically knocked the old outer racer free. Upturning the hub we then knocked out the inner seal, which allows the inner bearing to freely fall out, and then we knocked out the racer. We then thoroughly cleaned the hub with brake cleaner and rags.
With both new bearings, we pressed bearing grease within to ensure full coverage of all rollers, then set them aside. We placed the new inner racer in position (make sure it’s facing the right way) and gently hammered it in place using a bearing racer install tool Mitch had borrowed. Alternatively, you can use the old racer as a sacrificial buttress to prevent damaging the new racer (hint: grind down the outer edge of the old racer, so as it doesn’t get stuck in the hub). Once we had inserted the new racer, we placed the new inner bearing in its position. Next we gently hammered the new inner seal in place until flush with the hub face.
The outer racer is next and follows the same procedure as the inner unit, using the bearing racer install tool. We were now ready to place the hub back on the axle, which was moderately covered with bearing grease.
SECURING THE HUB IN PLACE ON THE SPINDLE/AXLE
Installation is reverse of assembly, but requires a few extra steps. Holding the assembly in place, we inserted the new outer bearing, then the thrush washer, then torqued the adjustment nut to 43lbs. Gripping the assembly we made three full turns left and then right to bed in the bearing and rechecked the torque, then fully loosened the adjustment nut and re-torqued to 18lbs.
We next put on the locking washer and then screwed the retaining nut to 43lbs and bent two locking washer tabs, one forward and one backwards, which secured both nuts. You may need to pull the axle slightly outwards to line up the retaining circlip, which was next.
With the end in sight, and using new gaskets and fresh grease, we re-positioned the cleaned hub body and tightened the six bolts with their cone and spring washers to 20lbs. Finally, we lined up the clean greased hub cover with its six bolts and torqued to 7lbs.
Check for smooth and proper operation before continuing.
That, folks, is the hardest part done.
CHANGING THE BRAKE PADS
Next, wipe around the caliper with an old brush to aid with cleaning. Then, loosen the cap on the brake reservoir to allow for any fluid expansion. To insert new pads inside the caliper, we used brute force to spread the caliper pistons apart to allow the new thicker pads to be inserted and slide over the rotor, and followed this by replacing the retaining spring and pins. Once lined up, we tightened the caliper’s two retaining bolts to 90lbs after dabbing them with Loctite for added assurance.
TIME TO HIT THE ROAD
After cleaning and replacing the wheels we checked the brake fluid level.
It’s imperative to take necessary steps to bed in the pads and rotors to ensure maximum performance and life. Some suggest starting at 60kph, then slowing down by applying moderate pressure without stopping fully; and to repeat this about 10 times. Then from about 70kph do another three slow-downs, applying heavy pressure without coming to a full stop.
All up it took us about 4.5 hours, including running back to Repco, to complete the job. Once again, I urge you to seek expert advice if in doubt, as the brake system must always be working at its best. Your life depends on it. No question! Happy Wheeling.