--- a/taskcluster/ci/legacy/tasks/branches/autoland/job_flags.yml
+++ b/taskcluster/ci/legacy/tasks/branches/autoland/job_flags.yml
@@ -1,24 +1,7 @@
 ---
 # For complete sample of all build and test jobs,
 # see <gecko>/testing/taskcluster/tasks/branches/base_job_flags.yml
 
 $inherits:
   from: tasks/branches/base_jobs.yml
 
-builds:
-  aries-eng:
-    platforms:
-      - b2g
-    types:
-      opt:
-        task: tasks/builds/b2g_aries_eng.yml
-      debug:
-        task: tasks/builds/b2g_aries_debug.yml
-  nexus-5l-eng:
-    platforms:
-      - b2g
-    types:
-      opt:
-        task: tasks/builds/b2g_nexus_5l_eng.yml
-      debug:
-        task: tasks/builds/b2g_nexus_5l_debug.yml

--- a/taskcluster/ci/legacy/tasks/branches/base_job_flags.yml
+++ b/taskcluster/ci/legacy/tasks/branches/base_job_flags.yml
@@ -6,18 +6,16 @@ flags:
     - linux32_gecko  # b2g desktop linux 32 bit
     - linux64_gecko  # b2g desktop linux 64 bit
     - linux64-mulet  # Firefox desktop - b2g gecko linux 64 bit
     - linux64-haz    # Firefox desktop browser, rooting hazard analysis
     - linux64-shell-haz  # JS shell, rooting hazard analysis
     - linux64-mulet-haz  # Firefox desktop - b2g gecko linux 64 bit, rooting hazard analysis
     - macosx64_gecko # b2g desktop osx 64 bit
     - win32_gecko    # b2g desktop win 32 bit
-    - nexus-5l-eng
-    - aries-eng
     - android-api-15
     - android-api-15-frontend
     - android-partner-sample1
     - android-x86
     - linux
     - linux-l10n    # Desktop l10n
     - linux64
     - linux64-l10n  # Desktop l10n

--- a/taskcluster/ci/legacy/tasks/branches/mozilla-central/job_flags.yml
+++ b/taskcluster/ci/legacy/tasks/branches/mozilla-central/job_flags.yml
@@ -5,31 +5,13 @@
 $inherits:
   from: tasks/branches/base_jobs.yml
 
 # Flags specific to this branch
 flags:
   post-build:
     - simulator
 
-builds:
-  aries-eng:
-    platforms:
-      - b2g
-    types:
-      opt:
-        task: tasks/builds/b2g_aries_eng.yml
-      debug:
-        task: tasks/builds/b2g_aries_debug.yml
-  nexus-5l-eng:
-    platforms:
-      - b2g
-    types:
-      opt:
-        task: tasks/builds/b2g_nexus_5l_eng.yml
-      debug:
-        task: tasks/builds/b2g_nexus_5l_debug.yml
-
 post-build:
   simulator:
     allowed_build_tasks:
       - tasks/builds/mulet_linux.yml
     task: tasks/post-builds/mulet_simulator.yml

--- a/taskcluster/ci/legacy/tasks/branches/mozilla-inbound/job_flags.yml
+++ b/taskcluster/ci/legacy/tasks/branches/mozilla-inbound/job_flags.yml
@@ -1,24 +1,6 @@
 ---
 # For complete sample of all build and test jobs,
 # see <gecko>/testing/taskcluster/tasks/branches/base_job_flags.yml
 
 $inherits:
   from: tasks/branches/base_jobs.yml
-
-builds:
-  aries-eng:
-    platforms:
-      - b2g
-    types:
-      opt:
-        task: tasks/builds/b2g_aries_eng.yml
-      debug:
-        task: tasks/builds/b2g_aries_debug.yml
-  nexus-5l-eng:
-    platforms:
-      - b2g
-    types:
-      opt:
-        task: tasks/builds/b2g_nexus_5l_eng.yml
-      debug:
-        task: tasks/builds/b2g_nexus_5l_debug.yml

--- a/taskcluster/ci/legacy/tasks/branches/try/job_flags.yml
+++ b/taskcluster/ci/legacy/tasks/branches/try/job_flags.yml
@@ -118,32 +118,16 @@ builds:
       debug:
         task: tasks/builds/dbg_linux64-asan.yml
   macosx64-st-an:
     platforms:
       - MacOSX64 Static Analysis
     types:
       opt:
         task: tasks/builds/opt_macosx64_st-an.yml
-  aries-eng:
-    platforms:
-      - b2g
-    types:
-      opt:
-        task: tasks/builds/b2g_aries_eng.yml
-      debug:
-        task: tasks/builds/b2g_aries_debug.yml
-  nexus-5l-eng:
-    platforms:
-      - b2g
-    types:
-      opt:
-        task: tasks/builds/b2g_nexus_5l_eng.yml
-      debug:
-        task: tasks/builds/b2g_nexus_5l_debug.yml
   sm-tsan:
     platforms:
       - Linux64
     types:
       opt:
         task: tasks/builds/sm_tsan.yml
     when:
       file_patterns:

deleted file mode 100644
--- a/taskcluster/ci/legacy/tasks/builds/b2g_aries_debug.yml
+++ /dev/null
@@ -1,37 +0,0 @@
-$inherits:
-  from: 'tasks/builds/b2g_phone_eng_base.yml'
-  variables:
-    build_name: 'aries'
-    build_type: 'debug'
-task:
-  scopes:
-    - 'docker-worker:cache:level-{{level}}-{{project}}-build-aries-debug'
-    - 'docker-worker:cache:level-{{level}}-{{project}}-build-aries-debug-objdir-gecko'
-    - 'docker-worker:relengapi-proxy:tooltool.download.internal'
-    - 'docker-worker:relengapi-proxy:tooltool.download.public'
-  metadata:
-    name: '[TC] B2G Aries Debug'
-
-  payload:
-    cache:
-      level-{{level}}-{{project}}-build-aries-debug: /home/worker/workspace
-      level-{{level}}-{{project}}-build-aries-debug-objdir-gecko: /home/worker/objdir-gecko
-    features:
-      relengAPIProxy: true
-    env:
-      TARGET: 'aries'
-      B2G_DEBUG: 1
-  extra:
-    treeherderEnv:
-      - production
-      - staging
-    treeherder:
-      symbol: Bd
-      groupSymbol: Aries
-      groupName: Aries Device Image
-      machine:
-        platform: b2g-device-image
-      collection:
-        debug: true
-    locations:
-      img: 'private/build/aries.zip'

deleted file mode 100644
--- a/taskcluster/ci/legacy/tasks/builds/b2g_aries_eng.yml
+++ /dev/null
@@ -1,34 +0,0 @@
-$inherits:
-  from: 'tasks/builds/b2g_phone_eng_base.yml'
-  variables:
-    build_name: 'aries-eng'
-    build_type: 'opt'
-task:
-  scopes:
-    - 'docker-worker:cache:level-{{level}}-{{project}}-build-aries-eng'
-    - 'docker-worker:cache:level-{{level}}-{{project}}-build-aries-eng-objdir-gecko'
-    - 'docker-worker:relengapi-proxy:tooltool.download.internal'
-    - 'docker-worker:relengapi-proxy:tooltool.download.public'
-  metadata:
-    name: '[TC] B2G Aries Eng'
-
-  payload:
-    cache:
-      level-{{level}}-{{project}}-build-aries-eng: /home/worker/workspace
-      level-{{level}}-{{project}}-build-aries-eng-objdir-gecko: /home/worker/objdir-gecko
-    features:
-      relengAPIProxy: true
-    env:
-      TARGET: 'aries'
-  extra:
-    treeherderEnv:
-      - production
-      - staging
-    treeherder:
-      symbol: Be
-      groupSymbol: Aries
-      groupName: Aries Device Image
-      machine:
-        platform: b2g-device-image
-    locations:
-      img: 'private/build/aries.zip'

deleted file mode 100644
--- a/taskcluster/ci/legacy/tasks/builds/b2g_nexus_5l_debug.yml
+++ /dev/null
@@ -1,37 +0,0 @@
-$inherits:
-  from: 'tasks/builds/b2g_phone_eng_base.yml'
-  variables:
-    build_name: 'nexus-5-l-eng'
-    build_type: 'debug'
-task:
-  scopes:
-    - 'docker-worker:cache:level-{{level}}-{{project}}-build-nexus-5-l-debug'
-    - 'docker-worker:cache:level-{{level}}-{{project}}-build-nexus-5-l-debug-objdir-gecko'
-    - 'docker-worker:relengapi-proxy:tooltool.download.internal'
-    - 'docker-worker:relengapi-proxy:tooltool.download.public'
-  metadata:
-    name: '[TC] B2G Nexus 5-L Debug'
-
-  payload:
-    cache:
-      level-{{level}}-{{project}}-build-nexus-5-l-debug: /home/worker/workspace
-      level-{{level}}-{{project}}-build-nexus-5-l-debug-objdir-gecko: /home/worker/objdir-gecko
-    features:
-      relengAPIProxy: true
-    env:
-      TARGET: 'nexus-5-l'
-      B2G_DEBUG: 1
-  extra:
-    treeherderEnv:
-      - production
-      - staging
-    treeherder:
-      symbol: Bd
-      groupSymbol: Nexus 5-L
-      groupName: Nexus 5-L Device Image
-      machine:
-        platform: b2g-device-image
-      collection:
-        debug: true
-    locations:
-      img: 'private/build/nexus-5-l.zip'

deleted file mode 100644
--- a/taskcluster/ci/legacy/tasks/builds/b2g_nexus_5l_eng.yml
+++ /dev/null
@@ -1,34 +0,0 @@
-$inherits:
-  from: 'tasks/builds/b2g_phone_eng_base.yml'
-  variables:
-    build_name: 'nexus-5-l-eng'
-    build_type: 'opt'
-task:
-  scopes:
-    - 'docker-worker:cache:level-{{level}}-{{project}}-build-nexus-5-l-eng'
-    - 'docker-worker:cache:level-{{level}}-{{project}}-build-nexus-5-l-eng-objdir-gecko'
-    - 'docker-worker:relengapi-proxy:tooltool.download.internal'
-    - 'docker-worker:relengapi-proxy:tooltool.download.public'
-  metadata:
-    name: '[TC] B2G Nexus 5-L Eng'
-
-  payload:
-    cache:
-      level-{{level}}-{{project}}-build-nexus-5-l-eng: /home/worker/object-folder
-      level-{{level}}-{{project}}-build-nexus-5-l-eng-objdir-gecko: /home/worker/objdir-gecko
-    features:
-      relengAPIProxy: true
-    env:
-      TARGET: 'nexus-5-l'
-  extra:
-    treeherderEnv:
-      - production
-      - staging
-    treeherder:
-      symbol: Be
-      groupSymbol: Nexus 5-L
-      groupName: Nexus 5-L Device Image
-      machine:
-        platform: b2g-device-image
-    locations:
-      img: 'private/build/nexus-5-l.zip'