Solid axle brake discs -- Land Cruiser

TLC Mag' August - Sept 2009 n° 24

Article by François WILLEMIN.

Photos: Hervé CAUCHIES & François WILLEMIN.

No one really needs reminding just how fundamentally important the brake system is on a vehicle.

Unfortunately, on older 4x4's we have to acknowledge that in the event of a critical situation the original front brake discs where not really up to the job.

To offer safer driving, Euro4x4parts have been supplying drilled and grooved double brake discs for a few years now. Using a 1989 vehicle, we compared the performance of the original discs with a set supplied by Euro4x4parts.

Let's get to the point the results where quite simply staggering!

Dime a dozen...

For our test we used a 4x4 weighing in at just under 2 tons at 90km/h on a dry, straight road.

Using the original discs (worn of course but still useable), we tested hard braking to a complete standstill five times. A couple of hours later we carried out the same test using the discs supplied by Euro4x4parts. We calculated an average braking for each set and the final results show an improvement of over 12 metres using the drilled and grooved discs.

Driving 12 metres is no big thing, but this distance becomes immensely important in an emergency braking situation. This difference could save lives.

Make or brake!

Although it's quite normal to change brake pads without having to change the discs (fortunately!) it would be unthinkable to change the discs without finishing the job with new pads.

With this in mind remember that quality in the brake pad market can vary greatly only buy these parts from a genuine specialist. Euro4x4parts recommend matching their drilled and grooved discs with high performance pads a vital means to optimise braking safety.

You're probably wondering what the real benefits are of drilling and machining grooves on a disc? The drilling ensures more effective cooling (even on ventilated discs) and the spiral grooves offer improved evacuation of pad dust. Remember that the spiral is machined for a particular direction of rotation and left-right fitting should not be inversed.

Down to work

We would like to thank the Presqu'île 4x4 garage in Lège-Cap Ferret who kindly let us into their workshop. Now it's time to roll up our sleeves and follow Christophe's advice step-by-step.

Warning

Wheel nuts excluded, only use an impact wrench for unscrewing.

Good looking and effective - the discs are supplied with high performance pads.

Having removed the wheel, pull the spring clip from behind the caliper.

Using a pin punch, push in the two pins that hold the pads.

Remove the pads having disconnected the two small springs.

This shows the original disc with a bluish tinge due to overheating.

Undo the six bolts on the locking hub (10mm socket).

Remove the caliper by undoing the 2 retaining bolts (17mm) at the back .

Pull the caliper away towards the inside (being careful not to damage the brake lines).

Remove the hub.

Remove the clip that retains the half shaft.

Loosen (not completely) the six cap nuts that hold the flange (12mm socket).

Use a small sharp tap next to each bolt to release the cone washers.

Remove the nuts and the split washers.

Now pull out the cone washers.

Now remove the flange.

Flatten the tabs of the lock nut star washer.

Undo the lock nut (54mm socket).

Remove the lock nut.

Remove the star locking washer.

Now unscrew the adjusting nut (54mm socket).

Remove the conical needle bearing.

Remove the hub and the disc as one.

Clean using a degreasing agent and check the condition of the seal.

Remove the two bolts that keep the disc centred (14mm).

Remove the studs (best on a press or with a bottle-jack or hammer).

Fitting the new disc.

Positioning the studs.

Pushing the studs on the press to relocate them "DIY style".

Refitting the hub and the new disc.

Thoroughly grease the axle (thick, heavy grease).

Refit the cone bearing and washer then the adjusting nut.

Tighten, but not fully (54mm socket).

Check wheel rotation.

Flatten the star lock washer (or fit a new one).

Fit the locking nut by hand.

Tighten firmly (54mm socket).

Block the adjusting nut by bending a lug of the star locking washer.

Now block the lock nut by bending a lug of the star locking washer.

Check that the nut is locked.

Refit the flange gasket (or use joint paste if it has been destroyed).

Refit the flange making sure it is correctly seated.

Refit the six cone washers.

Then fit the washers and the cap nuts.

Tighten the cap nuts (12mm socket). Don't use an impact wrench!

Screw an 8mm bolt 3 or 4 turns into the half shaft thread then pull. Remove the bolt.

Refit the clip on the half shaft.

Refit the hub - be careful to align the little lug...

...opposite the groove without teeth.

Refit the hub bolts tight but don't over tighten (10mm socket). Don't use an impact wrench!

Release the cap on the brake fluid reservoir, open up the pistons and fit the new pads.

Put the pad pins back in place then the retaining clips.

Refit the wheel and the job's done.

Thanks Christophe!