Arno: /* Pre-Warning */

Lotus Elise Rear Caliper Rebuild and Upgrade

This article originally contributed by 40mmBrakes ( http://40mmbrakes.auto.officelive.com/default.aspx )
===Pre-Warning===

'''Before you start taking things apart, first ensure that your calipers are servicable.'''
First make sure that you can remove the tiny grub screw that you can see in this photo. It needs a 4.5mm allen key which is a fairly unusual size. An alternative may be to use an imperial 3/16" allen key, although this is often a very tight fit and corrosion inside the allen socket may make it difficult to seat fully.

[[Image:grubscrew.JPG]]

Unfortunately the grub screw sits deeply recesed in the boss of the caliper by 10-12mm. By the time your calipers reach an age where they would befefit from new seals, the thread in the boss has become so corroded that it's nigh-on impossible to remove the grub screw.

A no-harm solution is to fill the cavity with penetrating oil and come back tomorrow. The screw is in tight because the tapered end acts as a fluid seal; there is brake fluid on the opposite side. Once it breaks loose, it may not be that difficult to remove.

A brute force solution is to take an angle grinder to the boss and remove the excess material. Cut the boss flush with the top of the grub screw. The heat generated by this also helps to free up the screw.

The other part to check is the 13mm bolt that holds the handbrake arm to the caliper. Make sure that this loosens as it has a tendency to go soft and shear off. In any case you should not expect the internals of the caliper to support the torque needed to loosen the bolt! The small parts that are engaged with parking brake actuation are not strong enough to resist the torque of a stuck bolt. You should put the handbrake arm (only) in a vise and unscrew the bolt so that the resistance torque is only applied to the arm.

Bear in mind that it's a straightforward job to refurb the sliders but examine your calipers carefully before attempting to replace the piston seals.

===Repair===

The service manual claims the [[Brembo Caliper]]s fitted to the rear [[brakes]] of the Elise are not fully serviceable.

These instructions were developed by disassembling and reassembling many calipers and are not perfect.

The Lotus Elise rear caliper is sometimes criticised as being too small. The rear caliper can be machined to accept a 38mm or even a 40mm piston and sleeve.

For the 38mm piston, you will need a Brembo 38mm seal, part number 05.5955.57

For the 40mm piston, you will need a Brembo 40mm seal, part number 05.5955.58

This conversion still allows the use of all the other standard size parts that come in the KC-83017 kit.

[[Image:Brembo_Caliper_6.JPG]]

== Procedure ==
=== Disassembly ===

[[Image:Brembo_Caliper_7.JPG]]

Unscrew piston as far as it will go using either a windback tool or stout needle nose pliers, one tip in each hole. Push in and rotate counter clockwise.

[[Image:Brembo_Caliper_8.JPG]]

As the dust boot stretches, pull it out of the groove.
The piston can be pried out with two screwdrivers. An internal snap ring holds it tightly, so be prepared to try a few times and apply some effort. Before it pops, it will feel “springy.” When the snap ring does pop, the piston will go flying, so put a rag over it to keep it from falling. You can use a socket on each side to support the screwdriver.

[[Image:Brembo_Caliper_9.JPG]]

Here’s the prying position (without the dust boot and rag). From this image you can get a perspective of how far up the piston will rise without coming out. The piston can also be removed with air pressure into the brake line supply inlet.

[[Image:Brembo_Caliper_10.JPG]]

Once the piston is out, do not turn the caliper over. There are several loose pieces inside that may fall out.

[[Image:Brembo_Caliper_11.JPG]]

NB Only follow the following procedure if you have access to a new screw as 80% of the time they shear off & are not available to buy separately. You can get the whole assembly with the snap-ring out of the bore with some curved tools (eg. bend a screwdriver ) so it comes out as 1 piece. (Courtesy of Arno)

Remove the dust boot.
With a 4mm allen key, remove the screw. This screw has an O-ring around the head, so do not reach in and use pliers. It is also held in with thread lock glue, so it feels a little stuck before it comes loose. It may also drag the whole way out. Use the proper allen key, since the metal is soft and you’ll easily round the hole.

[[Image:Brembo_Caliper_12.JPG]]

After the screw is removed, the threaded disc can be unscrewed and removed. This disc pushes on the inside of the piston when pulling on the parking brake.

[[Image:Brembo_Caliper_13.JPG]]

Without the disc, a ball bearing race, a snap ring, and two washers will be visible in the bore. Turn the caliper over to remove them.

[[Image:Brembo_Caliper_14.JPG]]

Here’s what will fall out:-

Ball bearing

Flat washer

Wave washer

Snap ring

[[Image:Brembo_Caliper_15.JPG]]

Removing the worm thread shaft is next.
Look down into the bore for the internal snap ring. It has several tabs bent to point up at you. With a flat screwdriver, pry the tabs at the ends of the snap ring towards the center of the bore and disengage it from the groove in the wall.

[[Image:Brembo_Caliper_16.JPG]]

Now the worm shaft (and snap ring) can be removed. Notice the tabs.

[[Image:Brembo_Caliper_17.JPG]]

Unscrew the hex stop peg in the boss of the caliper. You will need a 4.5mm allen key which is an uncommon size.

[[Image:Brembo_Caliper_18.JPG]]

Remove the parking brake lever, parking brake shaft dust seal, and push the shaft into the caliper body.
The flat washer tends to stick in the caliper, be sure not to miss it.

[[Image:Brembo_Caliper_19.JPG]]

Remove the ball bearing drive plate, the needle bearing, and the flat washer.
Remove the old piston seal.

=== Reassembly ===

[[Image:Brembo_Caliper_20.JPG]]

Install a new parking brake drive plate shaft O-ring, if needed.
Reinstall the flat washer, needle bearing, and ball bearing drive plate of the parking brake in the caliper body. Make note of where the three ball bearings are; you will need to mate them with the driven plate later.

[[Image:Brembo_Caliper_21.JPG]]

The internal assembly will go back together in this order:-

Wave washer

Flat washer

Ball bearing

Cone screw

Use some thread lock on the O-ringed screw on reassembly.
Install a new O-ring on the screw.

[[Image:Brembo_Caliper_22.JPG]]

To reassemble the caliper, insert assembly into the piston and snap the {coat-hanger quality) internal snap ring into the piston.

[[Image:Brembo_Caliper_23.JPG]]

The snap ring groove is just inside the piston.

[[Image:Brembo_Caliper_24.JPG]]

Take the internal snap ring with the tabs, point the tabs downward, and use the tabs to clip the snap ring into the bottom
edge of the piston.

[[Image:Brembo_Caliper_25.JPG]]

Then screw the worm shaft into the piston as far as it will go.
Install the new piston seal.

[[Image:Brembo_Caliper_26.JPG]]

Stretch the new dust boot over the bottom of the assembled piston, leaving the lower edge of the boot to hang down. You will have to hold the piston over the bore and insert the boot lip into the groove all the way around before inserting the piston into the bore. The boot should look even (no bumps) if done properly.
Make note of where the ball bearing detents are.

[[Image:Brembo_Caliper_27.JPG]]

This is the tricky part. With the boot in the groove, centre the piston to begin pushing it into the bore. Use a c-clamp with a socket covering the parking brake shaft sticking out the bottom, making sure the clamp is pushing the piston straight down. Besides the normal problem of getting past the boot lip and the seal, the driven plate detents and the drive plate ball bearings must mate, otherwise you will not be able to push the piston down far enough for the internal snap ring to find it’s groove.
If the clamp seems to come to a stop and you have not heard the snap ring snap into place, try to rotate the clamp to rotate the piston and line up the ball bearing detents.
A second way is to temporarily attach the parking brake lever under the clamp to rotate the lever, which will move the drive ball bearings back and forth to line everything up.
Rotate the lever clockwise when facing the lever, as this also screws the threaded shaft into the cone shaped washer (ensuring that the piston is not bottoming on the parking brake adjustment.)
In any case, the piston will seem to be very low, lower than the dust boot wrinkles, before the snap ring engages. If the snap ring does not engage, the parking brake system has nothing to push on to “disengage.”

Hint 1: A G-clamp may not provide sufficient force to engage the snap ring. It may take 2-3 tons of pressure on a bench press before you hear the snap ring click into position.

Hint 2: Sometimes you can't push on the brake lever arm with the C-clamp to insert piston, you need to take off the arm and push on casting using socket.

Hint 3: Tons of force may not really be necessary. There are two ways to do it even without a G-clamp. The first way is to wind in the worm shaft in to compress the spring - if you're lucky there will be enough friction to hold the spring compressed. Listen whilst you reassemble it in case it comes un-sprung. If it stays sprung, you should be able to get the snap ring to snap by hand pressure on the piston. Alternatively, mount the caliper in a vice. Using a pair of circlip pliers or whatever tool you use to retract the piston, wind the piston clockwise while at the same time applying a reasonable amount of pressure to drive the piston into the caliper. You should hear the circlip click in place.

When the snap ring engages, reinstall the hex head stop peg.
Using the parking brake lever, rotate the parking brake shaft while looking down into the stop peg boss. You will see the detent in the foot of the worm shaft. Screw in the stop peg so it engages the detent.
You can check the proper operation by now rotating the parking brake lever again (which will push the piston out) and then rotating the opposite direction (which should slightly pull the piston back in.) With larger swings of the lever, this becomes a ratcheting action, so repeated back and forth with the lever will eventually move the piston further and further out; if the snap ring is engaged properly, the piston will slightly retract after each lever movement.

[[Image:Brembo_Caliper_28.JPG]]
[[Image:Brembo_Caliper_29.JPG]]

Once installed, the new 38mm calipers look exactly like the standard system.

Notes:
The brakes usually have to bled twice. It seems that air is trapped in the piston (the recess for the threaded parking brake adjustment rod) that isn’t flushed out during caliper installation.
The O-ring screw is a 10-32 thread. About 10% of the time it breaks when trying to remove it.

[[Category:Brakes]]
[[Category:Lotus Elise]]
[[Category:S1]]
[[Category:S2]]

Replace wheel bearings

2010-05-02T12:27:59Z

Arno:

=Replace Wheel Bearings=

==Elise S1==

'''Please Add Info'''

==Elise S2==

All S2 Elises (irrespective of engine type) use a similar type of wheel bearing. The only difference between these is that the later cars with ABS use bearings with integraded speed pulse sensors for the ABS, while older cars without ABS use 3 'plain' bearings and 1 with a speed pulse sensor.

The latter connects to the ECU which in turn feeds a signal to the dash.

===Basic design===

The wheel bearings on the S2 are complete units that are bolted to the uprights. The bearing units are sealed for life and not servicable. They can not be opened without being destroyed.

The bearing and hub come as a complete package ready to install. On the upright side there are 3 bolt holes (M12 metric fine) which line up with the holes in the uprights.

The bearing units are bolted to the uprights with 90Nm of torque on each bolt.

Bolts can usually be re-used, but examine them for corrosion (pitting) or other damage. In case of doubt, replace with new ones.

* Lotus part number for bolts: A116W1170F

===Front===

====Removal====

* Undo the wheel bolts
* Jack up the car on the 'A' jacking point to raise the side of the car off the floor.
* For added security place some support next to the jack
* Remove front wheel

If an M16 clamp-bolt is fitted through the hub (not required, but recommended):
* Attach a size 24 ring spanner to the back so it locks against the lower wishbone
* Put a rag between the spanner and the wishbone
* Use a breaker bar and size 24 socket to undo the M16 bolt
* Remove the bolt and washers, taking care not to mix up the washer types
* Clean the bolt and nut, treat with anti-corrosion

* Use pliers/clamp to push brake caliper pistons back (check reservoir!)
* Use 8mm key to undo allen-bolts holding caliper to upright
* Remove caliper and position on top of upper wishbone (may need to undo P-clip for brake line)

* Remove M5 allen bolt holding brake disc on hub
* Lift brake disc from hub

The hub and bearing pack are now visible and accessible. You will notice that there are pry slots on the outer edges of the bearing pack where it mounts to the upright.

* Disconnect speed sensor plug if required
* Turn steering completely to one side
* Depending on the type of bolt used, use a 19MM socket, 10MM allen head (or possibly E18 star socket, T55 torx head) and a breaker bar to undo the three bolts than hold the bearing pack to the upright
* Turn steering wheel straight again
* Use a chisel and lump hammer on the pry slots to separate the bearing from the upright (rust and dirt will make it 'stick')
* If you will not re-use the old bearing you can also hit the flange from the back with a lump hammer (this damages the bearing, so do not use this if re-using the bearing!)
* After several hits on the pry slots the bearing pack will fall out of the upright

The old bearing pack is now removed from the upright and the new one can be installed.

====Installation====

* Using some coarse sandpaper on a fabric backing (eg. grit 60-80) work on the opening of the upright where the bearing pack sits to remove all of the rust and dirt buildup
* Clean out the bolt holes
* Clean and de-grease surfaces properly so no grit and dirt is present anymore
* Apply some anti-seize (eg. ceramic grease) along the edge of the hole so the new bearing pack will seat properly and can be removed easier later.
* Offer up the new bearing pack to the upright
* Depending on tolerances it may slide into place immediately or need pulling in by using the bolts (this seems to vary)
* If the original bolts are OK, insert these from the back of the upright and tighten them finger-tight
* Turn steering wheel to one side again
* Using a torque wrench do up the bolts in a circular pattern until they are all tightened to 90Nm
* Check that the bearing pack sits flat and true on the upright

If an M16 clamp-bolt was fitted through the hub (not required, but recommended):
* Re-install clamp bolt and washers, coat washer surfaces with some form of anti-corrosion grease
* Attach a size 24 ring spanner to the back so it locks against the lower wishbone
* Put a rag between the spanner and the wishbone
* Use a torque wrench to tighten the M16 nut to 220Nm

* Re-connect speed sensor plug if required
* Clean brake disc inner mating surface to hub
* Install brake disc on hub
* Install M5 allen bolt holding brake disc on hub

* Install front caliper (may need to replace P-clip for brake line if undone earlier)
* Refit allen-bolts holding caliper to upright
* Use a torque wrench to tighten to 45Nm each
* Re-fit wheel
* Apply brake pedal a few times to re-seat brake pads/pistons

Have a cuppa!

===Rear===

====Removal====

* Apply handbrake and put car in 1st gear
* Undo the wheel bolts
* Jack up the car on the 'A' jacking point to raise the side of the car off the floor.
* For added security place some support next to the jack
* Remove rear wheel

* Remove split pin that secures castellated nut on driveshaft
* Use a breaker bar and deep size 30 socket or a size 30 ring spanner on the castellated nut and undo
* Remove the nut and washer
* Push the driveshaft into the hub to make sure it's free

* Release handbrake (keep car in gear!)
* Remove lock pin and spring from brake caliper
* Remove front pad by tapping it down and inboard
* Use 6mm key to undo lower allen-bolt holding caliper to upright
* Use 17mm socket to undo upper bolt holding caliper to upright
* Remove caliper and position on top of diffuser/undertray (may need to undo P-clip for brake line)

* Remove M5 allen bolt holding brake disc on hub
* Lift brake disc from hub

If the driveshaft was stuck in the bearing earlier, now a 3-prong bearing puller can be used to press the driveshaft out of the bearing.

The hub and bearing pack are now visible and accessible. You will notice that there are pry slots on the outer edges of the bearing pack where it mounts to the upright.

* Disconnect speed sensor plug if required
* Undo nut of outer trackrod joint to upright
* Disconnect trackrod taking care to note order and type of washers
* Swivel upright out carefully, making sure you do not pull the driveshaft from the CV joint
* Use 8mm allen key to undo the upper mounting plinth bolts that connect the balljoint to the upright
* Catch the camber shims that fall out and make note of the amount

Now the upright is only connected to the lower balljoint and can swivel relatively freely.

* Swivel and tilt the upright so the splined end of the driveshaft can be withdrawn from the bearing
* Move driveshaft out of the way and re-attach upper plinth temporarily
* Swivel upright to it's (more or less) perpendicular to car

* Depending on the type of bolt used, use a 19MM socket, 10MM allen head (or possibly E18 star socket, T55 torx head) and a breaker bar to undo the three bolts than hold the bearing pack to the upright
* Turn upright straight ahead
* Use a chisel and lump hammer on the pry slots to separate the bearing from the upright (rust and dirt will make it 'stick')
* If you will not re-use the old bearing you can also hit the flange from the back with a lump hammer (this damages the bearing, so do not use this if re-using the bearing!)
* After several hits on the pry slots the bearing pack will fall out of the upright

The old bearing pack is now removed from the upright and the new one can be installed.

====Installation====

* Using some coarse sandpaper on a fabric backing (eg. grit 60-80) work on the opening of the upright where the bearing pack sits to remove all of the rust and dirt buildup
* Clean out the bolt holes
* Clean and de-grease surfaces properly so no grit and dirt is present anymore
* Apply some anti-seize (eg. ceramic grease) along the edge of the hole so the new bearing pack will seat properly and can be removed easier later.
* Offer up the new bearing pack to the upright
* Depending on tolerances it may slide into place immediately or need pulling in by using the bolts (this seems to vary)
* If the original bolts are OK, insert these from the back of the upright and tighten them finger-tight
* Swivel upright to it's (more or less) perpendicular to car
* Using a torque wrench do up the bolts in a circular pattern until they are all tightened to 90Nm
* Check that the bearing pack sits flat and true on the upright

* Clean and de-grease the splined end of the driveshaft and make sure no dirt or grit is present
* Apply some anti-seize grease lightly to splines and mating surface of driveshaft
* Undo upper plinth bolts again
* Swivel and tilt the upright so the splined end of the driveshaft can be inserted into the bearing

* Re-fit camber shims and bolts holding upper mounting plinth to upright
* Use a torque wrench to tighten the bolts to 45Nm (8.8 grade bolts) or 60Nm (10.9 or 12.9 grade bolts)

* Re-fit trackrod and washers
* Torque nut of outer trackrod joint to upright (OEM spec nut and balljoint 74Nm, aftermarket, see supplier docs)

* Re-connect speed sensor plug if required

* Push the driveshaft fully through the hub so it seats properly
* Install washer and castellated nut
* Use a torque wrench to tighten the castellated nut to 220Nm (if this turns the driveshaft/engine, wait until caliper re-fitted)
* Insert split pin that secures castellated nut on driveshaft and hammer ends over to secure it

* Clean brake disc inner mating surface to hub
* Install brake disc on hub
* Install M5 allen bolt holding brake disc on hub

* Push/screw brake caliper piston back
* Install caliper with inner pad in place (may need to replace P-clip for brake line if undone earlier)
* Refit allen-bolt and M10 bolt holding caliper to upright
* Use a torque wrench to tighten allen bolt to 28Nm and M10 to 45Nm
* Re-fit outer pad, spring and locking pin
* Apply brake pedal a few times to re-seat brake pads/pistons
* Apply handbrake
* If you were unable to set the correct torque on the center nut, try again now.
* Re-fit wheel

All Done!

[[Category:Suspension]]
[[Category:Lotus Elise]]
[[Category:S1]]
[[Category:S2]]

2010-05-01T20:58:40Z

Arno: /* Front */

Replace wheel bearings

2010-05-01T20:57:27Z

Arno: /* Front */

Replace wheel bearings

2010-05-01T20:55:54Z

Arno:

Replace wheel bearings

2010-05-01T20:55:25Z

Arno: