diff --git a/source/java/org/alfresco/repo/content/caching/cleanup/CachedContentCleaner.java b/source/java/org/alfresco/repo/content/caching/cleanup/CachedContentCleaner.java
index f1bd735161..44278bc88e 100644
--- a/source/java/org/alfresco/repo/content/caching/cleanup/CachedContentCleaner.java
+++ b/source/java/org/alfresco/repo/content/caching/cleanup/CachedContentCleaner.java
@@ -20,7 +20,6 @@ package org.alfresco.repo.content.caching.cleanup;
 
 import java.io.File;
 import java.util.Date;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import org.alfresco.repo.content.caching.CacheFileProps;
 import org.alfresco.repo.content.caching.ContentCacheImpl;
@@ -46,7 +45,6 @@ public class CachedContentCleaner extends Thread implements FileHandler, Applica
     private ContentCacheImpl cache;   // impl specific functionality required
     private long minFileAgeMillis = 0;
     private Integer maxDeleteWatchCount = 1;
-    private ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
     private boolean running;
     private UsageTracker usageTracker;
     private long newDiskUsage;
@@ -58,7 +56,6 @@ public class CachedContentCleaner extends Thread implements FileHandler, Applica
     private Date timeFinished;
     private ApplicationEventPublisher eventPublisher;
     private long targetReductionBytes;
-    private boolean cleanRequested;
     private String reasonMessage;
    
     
@@ -99,9 +96,9 @@ public class CachedContentCleaner extends Thread implements FileHandler, Applica
         execute(reason);
     }
     
-    private synchronized void doClean()
-    {
-        while (running || (!cleanRequested))
+    private void doClean()
+    {   
+        synchronized(this)
         {
             try
             {
@@ -112,7 +109,6 @@ public class CachedContentCleaner extends Thread implements FileHandler, Applica
                 // Nothing to do.
             }
         }
-        
         running = true;
         if (log.isInfoEnabled())
         {
@@ -138,18 +134,19 @@ public class CachedContentCleaner extends Thread implements FileHandler, Applica
                         ", target: " + targetReductionBytes + " bytes");
         }
         
-        cleanRequested = false;
         this.targetReductionBytes = 0;
         running = false;
         
-        notifyAll();
+        synchronized(this)
+        {
+            notifyAll();
+        }
     }
     
     
     public synchronized void execute(String reasonMessage)
     {
         this.reasonMessage = reasonMessage;
-        cleanRequested = true;
         notifyAll();
     }
     
@@ -386,15 +383,7 @@ public class CachedContentCleaner extends Thread implements FileHandler, Applica
 
     public boolean isRunning()
     {
-        lock.readLock().lock();
-        try
-        {
-            return running;
-        }
-        finally
-        {
-            lock.readLock().unlock();
-        }
+        return running;
     }
     
     public long getNumFilesSeen()
diff --git a/source/java/org/alfresco/repo/content/caching/quota/StandardQuotaStrategyTest.java b/source/java/org/alfresco/repo/content/caching/quota/StandardQuotaStrategyTest.java
index ab1df2a376..78e0384777 100644
--- a/source/java/org/alfresco/repo/content/caching/quota/StandardQuotaStrategyTest.java
+++ b/source/java/org/alfresco/repo/content/caching/quota/StandardQuotaStrategyTest.java
@@ -29,7 +29,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Comparator;
 import java.util.List;
 
 import org.alfresco.repo.content.ContentContext;
@@ -48,7 +47,6 @@ import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import org.mozilla.javascript.ObjToIntMap.Iterator;
 import org.springframework.context.ApplicationContext;
 
 /**
@@ -191,4 +189,82 @@ public class StandardQuotaStrategyTest
     {
         return FileUtils.listFiles(cacheRoot, new SuffixFileFilter(".bin"), TrueFileFilter.INSTANCE);
     }
+        
+    
+    /**
+     * Not a unit test, but useful to fire up a lot of writers that will push the
+     * CachingContentStore's StandardQuotaStrategy beyond the panic threshold. The
+     * behaviour can then be monitored with, for example, a profiler.
+     * 
+     * @throws Exception
+     */
+    private void concurrencySmokeTest() throws Exception
+    {
+        StandardQuotaStrategyTest.beforeClass();
+        setUp();
+        // Need to set maxDeleteWatch count to > 0
+        // (0 is useful in unit tests, but for real usage must not be used)
+        cleaner.setMaxDeleteWatchCount(1);
+        
+        final int numThreads = 100;
+        Thread[] writers = new Thread[numThreads];
+        for (int i = 0; i < numThreads; i++)
+        {
+            final String threadName = "WriterThread[" + i + "]";
+            Runnable runnable = new Runnable()
+            {
+                @Override
+                public void run()
+                {
+                    while (true)
+                    {
+                        writeFile();
+                        pause();
+                    }
+                }
+                
+                private void writeFile()
+                {
+                    try
+                    {
+                        writeSingleFileInMB(1); 
+                    }
+                    catch (IOException error)
+                    {
+                        throw new RuntimeException(threadName + " couldn't write file.", error);
+                    }
+                }
+                
+                private void pause()
+                {
+                    long pauseTimeMillis = Math.round(Math.random() * 2000);
+                    try
+                    {
+                        Thread.sleep(pauseTimeMillis);
+                    }
+                    catch (InterruptedException error)
+                    {
+                        // Swallow the exception and carry on.
+                        System.out.println(threadName + " InterruptedException.");
+                    }
+                }
+            };
+            Thread writerThread = new Thread(runnable);
+            writerThread.setName(threadName);
+            writers[i] = writerThread;
+            
+            writerThread.start();
+        }
+                
+//        StandardQuotaStrategyTest.afterClass();
+    }
+    
+    
+    
+    public static void main(String[] args) throws Exception
+    {
+        StandardQuotaStrategyTest test = new StandardQuotaStrategyTest();
+        test.concurrencySmokeTest();
+    }
+
 }
diff --git a/source/test-resources/cachingstore/test-std-quota-context.xml b/source/test-resources/cachingstore/test-std-quota-context.xml
index da9ee10404..07580f16fd 100644
--- a/source/test-resources/cachingstore/test-std-quota-context.xml
+++ b/source/test-resources/cachingstore/test-std-quota-context.xml
@@ -16,7 +16,7 @@
           class="org.alfresco.repo.content.caching.quota.StandardQuotaStrategy"
           init-method="init"
           destroy-method="shutdown">
-        <property name="maxUsageBytes" value="20971520"/><!-- 20971520 = 20MB -->
+        <property name="maxUsageMB" value="20"/>
         <property name="cleaner" ref="cachedContentCleaner"/>
         <property name="cache" ref="contentCache"/>
     </bean>