Differences

This shows you the differences between two versions of the page.

--- articles:400e_brake_caliper_rebuild [2021/12/20 08:15] – john5788
+++ articles:400e_brake_caliper_rebuild [2021/12/30 08:47] (current) – [Reassemble] john5788
@@ Line 35: / Line 35: @@
     - Use 1.5" piece of wood on a pair of opposing pistons to prevent them from moving
     - Use brake piston pliers if necessary
-  - Remove square seal in cylinder
   - Remove piston dust boot seal
+  - Remove square seal in cylinder
 </col>
 <col sm="6">
@@ Line 166: / Line 166: @@
 ===== Rear Calipers =====
+Procedures to disassemble and rebuild the rear calipers are very similar to the front. The major difference being the metal heat shield and piston orientation during reassembly.
 ==== Disassemble ====
+Disassembly does not include separating the caliper halves. If the caliper halves are not leaking brake fluid, then there is no reason to separate the halves and replace the special o-ring inside. Furthermore, Mercedes does not recommend separating the calipers for special torque procedures that are not easily replicated.
+<image shape="responsive">{{articles:MBZ_warning_dont_separate_calipers.png}}</image>
+<grid>
+<col sm="6">
+  - Remove metal heat shields from pistons by prying out with screwdriver
+  - Force compressed air (100 psi) into the hole where the brake line goes to remove pistons
+    - Use 1" piece of wood as a stop for the pistons
+    - Use brake piston pliers if necessary
+  - Remove piston dust boot seal
+  - Remove square seal in cylinder
+</col>
+<col sm="6">
+<grid>
+<col sm="6">
+<thumbnail>
+{{ articles:400erearbrakespryheatshield.jpg?300 }}
+<caption>Pry out heat shield with screwdriver</caption>
+</thumbnail>
+</col>
+<col sm="6">
+<thumbnail>
+{{ articles:400ebrakesrearpistonremoval.jpg?300 }}
+<caption>Using compressed air to remove pistons</caption>
+</thumbnail>
+</col>
+<col sm="6">
+<thumbnail>
+{{ articles:400erearbrakesremovedustseal.jpg?300 }}
+<caption>Removing dust seal</caption>
+</thumbnail>
+</col>
+</grid>
+</col>
+</grid>
 ==== Reassemble ====
+Refinishing the calipers with paint or powder coat is recommended. Make sure to mask off appropriate areas before painting (inside the caliper, pistons, dust seal groove, bleeder thread, brake line thread, mounting threads, sensor wear bracket mounting thread)
+To rebuild the rear calipers, the repair kit (000 421 72 86, requires 2) needs to be ordered. This kit comes with the square seals, dust seals, and the metal heat shields required for caliper reassembly.
+<image shape="responsive">{{ parts:0004217286.jpg }}</image>
+\\
+<grid>
+<col sm="6">
+  - Clean the caliper. Blow out any remaining paint dust, dirt, or oil from inside the caliper through the holes for the brake line, bleeder valve, and inside the cylinders
+  - Install new square seals in cylinder bore
+  - Clean the pistons
+  - Install dust cap on the piston
+  - Lubricate piston and cylinder with brake assembly fluid and reinsert piston into cylinder bore.
+    - Check orientation of piston with heat shield before inserting piston into cylinder bore
+    - Use a long screw driver or a long 1/4" extension across the top of the piston to help drive the piston down
+  - Seal dust cap along the collar of the cylinder bore
+  - Install new metal heat shields on top of the pistons
+    - Use caliper piston compressor if necessary
+  - Install new brake bleeder valves
+</col>
+<col sm="6">
+<grid>
+<col sm="6">
+<thumbnail>
+{{ articles:400ebrakesrearpistonorientation.jpg?300 }}
+<caption>Pay attention to piston orientation with metal heat shield</caption>
+</thumbnail>
+</col>
+<col sm="6">
+<thumbnail>
+{{ articles:400ebrakespistoncompressorinstallheatshield.jpg?300 }}
+<caption>Using a piston compressor to install heat shield</caption>
+</thumbnail>
+</col>
+</grid>
+</col>
+</grid>