diff --git a/.drone.yml b/.drone.yml
index 325abc9..c07d029 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -1,7 +1,7 @@
 ---
 kind: pipeline
 type: vm
-name: Build for RPI2
+name: build_rpi2
 
 pool:
   use: do-docker-20-04
@@ -41,7 +41,6 @@ steps:
 - name: save packages
   image: plugins/s3-cache
   settings:
-    pull: true
     endpoint: https://s3.ap-northeast-1.wasabisys.com
     root: "imi415-ci-artifacts"
     access_key:
@@ -49,7 +48,6 @@ steps:
     secret_key:
       from_secret: cache_aks
     rebuild: true
-    flush: true
     filename: "packages_rpi2.tar"
     mount:
       - ./dl
@@ -57,7 +55,6 @@ steps:
 - name: restore compiler cache
   image: plugins/s3-cache
   settings:
-    pull: true
     endpoint: https://s3.ap-northeast-1.wasabisys.com
     root: "imi415-ci-artifacts"
     access_key:
@@ -74,7 +71,6 @@ steps:
 - name: save compiler cache
   image: plugins/s3-cache
   settings:
-    pull: true
     endpoint: https://s3.ap-northeast-1.wasabisys.com
     root: "imi415-ci-artifacts"
     access_key:
@@ -82,7 +78,6 @@ steps:
     secret_key:
       from_secret: cache_aks
     rebuild: true
-    flush: true
     filename: "ccache_rpi2.tar"
     mount:
       - ./ccache
@@ -90,7 +85,7 @@ steps:
 ---
 kind: pipeline
 type: vm
-name: Build for T113i
+name: build_t113i
 
 pool:
   use: do-docker-20-04
@@ -130,7 +125,6 @@ steps:
 - name: save packages
   image: plugins/s3-cache
   settings:
-    pull: true
     endpoint: https://s3.ap-northeast-1.wasabisys.com
     root: "imi415-ci-artifacts"
     access_key:
@@ -146,7 +140,6 @@ steps:
 - name: restore compiler cache
   image: plugins/s3-cache
   settings:
-    pull: true
     endpoint: https://s3.ap-northeast-1.wasabisys.com
     root: "imi415-ci-artifacts"
     access_key:
@@ -163,7 +156,6 @@ steps:
 - name: save compiler cache
   image: plugins/s3-cache
   settings:
-    pull: true
     endpoint: https://s3.ap-northeast-1.wasabisys.com
     root: "imi415-ci-artifacts"
     access_key:
@@ -171,7 +163,29 @@ steps:
     secret_key:
       from_secret: cache_aks
     rebuild: true
-    flush: true
     filename: "ccache_t113i.tar"
     mount:
       - ./ccache
+
+---
+kind: pipeline
+type: docker
+name: Cache Management
+
+steps:
+- name: flush old cache
+  image: plugins/s3-cache
+  pull: true
+  settings:
+    endpoint: https://s3.ap-northeast-1.wasabisys.com
+    root: "imi415-ci-artifacts"
+    access_key:
+      from_secret: cache_ak
+    secret_key:
+      from_secret: cache_aks
+    flush: true
+    flush_age: 90
+
+depends_on:
+  - build_rpi2
+  - build_t113i