4000 Brakes Page

Front Strut and brakes

Front rotor showing even wear and decent pad contact.

The above photo shows the size difference between the 5000/200 and 4000Q carrier bolts

Just for comparison, the far right one is a triple square for the CV axle.

These are the replacement carrier bolts I sourced.

Two new ones to replace the old ones. 

Torque is around 50 Ft lbs.  Check the Bentley Manual.

I put on new guide pin boots over the pins.

Here the pads are installed over the rotor, ready to accept the caliper itself.



The piston CAN be pressed in with a brake tool,

but a 8? mm hex socket is "supposed" used to "wind" them in.

Rear rotor showing little wear or pad contact.

Here the caliper is resting on the carriers and the piston is pushed in.

The pad contact surfaces are greased with high temperature silicone brake grease.

Here the brake pads are greased along their contact points.

Using the torque wrench to tighten the guide pins,

  greased pads and loosened piston caliper assembly.

Bleeder screws

Mine were butchered, but I got all four to open with vise grips.

AutoZone (.com) stocked them for $1.99 each

SKU: 13955

Wheel locks up?

A closer look:

The passenger front wheel locked up when I returned home.

This was turning into the driveway using high pedal effort. (fast traffic behind me)

The front wheel locked (and skidded) but released when I backed up

and would lock again under application of the pedal.

I backed up again and E-braked the remaining 40 feet into my parking spot. 

My initial reaction was the drilled rotor had cracked and was hanging the pad's.

However, moving the car weeks later sounded like rotor grinding

against something (like a warped rotor sound - but it would come and go)

All diagnosis was rolling the car forward and back by clutch no faster than you would push a car.

Previously brakes seemed fine, even wear, rears just redone

and fronts inspected with guide pins moving freely.  See photos below:

Initial wheel removal inspection showed nothing a-miss.

Second inspection (a week later, when I had time and tools) showed nothing but frozen guide pins.

The clue (I think) came when I used the wrench to remove the caliper carrier bolts.

In order to take the front rotor off, I had to undo the caliper carrier bolts from the hub assembly.

It JUST so happens they are 17MM, 6 point bolt heads, like the wheel lug bolts. 

In fact, I used the wheel bar supplied with your new car to remove the wheel bolts.

There was only the upper carrier bolt there.

This seems to lead me in the direction that the carrier and caliper was cocked

at an angle that caused the rotor to BIND against the pads and

eventually lock up at slow wheel revolutions when the pedal was used.


For all I know the bolt could have fallen out as I turned into the driveway...............

Here is the pad wear, which seems even but not exactly parallel to the pad edge.


Although the pads exhibit even wear and "normal" characteristics,

placing the two square edges together, reveals tapered wear and some light chipping.

These rotors are showing surface rust from sitting unused for two weeks or so.

Here is the rotor at inspection during the track event.

Below is the exact wheel area during my Tech inspection at LRP, 30 hours before. 

I focused here particularly because I wasn't sure the nut holding the bolt

securing the ball joint was original equipment (O.E.) or the correct size.

The lower caliper bolt appears to be in the photo. ( upper right edge )

I'm not sure if the pad wear is the shiny streak near the rotor edge or just scoring.

However, it does directly fall into the tapered drill marks.

I'll relube the guide pins and consider two carrier bolts the solution to this problem.

October 2005

Mont Tremblant toasted the front drivers pads:  Frozen guide pins.

All other sets were 3/4 depth after two track events and 2,000 miles.

Some like it THIN department.

I heated them so much the piston reshaped the backing plates.

The center material gave way, disintegrated.

Notice the wire tops are gone on both pads.

Pure backing plate on the Left.  The right pad jammed at a tapered angle.

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