diff --git a/tools/run_tests/run_xds_tests.py b/tools/run_tests/run_xds_tests.py
index fe49271f5b9..5ed11501cdf 100755
--- a/tools/run_tests/run_xds_tests.py
+++ b/tools/run_tests/run_xds_tests.py
@@ -400,21 +400,6 @@ def wait_until_all_rpcs_go_to_given_backends(backends,
                                    num_rpcs,
                                    allow_failures=False)
 
-def wait_until_all_rpcs_fail(timeout_sec, num_rpcs):
-    start_time = time.time()
-    error_msg = None
-    logger.debug('Waiting for %d sec until all of next %d RPCs fail' %
-                 (timeout_sec, num_rpcs))
-    while time.time() - start_time <= timeout_sec:
-        error_msg = None
-        stats = get_client_stats(num_rpcs, timeout_sec)
-        diff = num_rpcs - stats.num_failures
-        if not diff :
-            error_msg = 'Unexpected completion for %d RPCs' % diff
-            time.sleep(2)
-        else:
-            return
-    raise RpcDistributionError(error_msg)
 
 def wait_until_rpcs_in_flight(timeout_sec, num_rpcs):
     start_time = time.time()
@@ -434,6 +419,7 @@ def wait_until_rpcs_in_flight(timeout_sec, num_rpcs):
             return
     raise RpcDistributionError(error_msg)
 
+
 def compare_distributions(actual_distribution, expected_distribution,
                           threshold):
     """Compare if two distributions are similar.
@@ -1075,8 +1061,7 @@ def test_circuit_breaking(gcp,
         configure_client([messages_pb2.ClientConfigureRequest.RpcType.UNARY_CALL],
                          [(messages_pb2.ClientConfigureRequest.RpcType.UNARY_CALL,
                            'rpc-behavior', 'keep-open')])
-        wait_until_all_rpcs_fail(int(_WAIT_FOR_STATS_SEC + _NUM_TEST_RPCS / args.qps),
-                                 _NUM_TEST_RPCS)
+        wait_until_all_rpcs_go_to_given_backends_or_fail([], _WAIT_FOR_BACKEND_SEC)
         _assert_rpcs_in_flight(max_requests)
 
         # Increment circuit breakers max_requests threshold.
@@ -1086,8 +1071,7 @@ def test_circuit_breaking(gcp,
                                 circuit_breakers={'maxRequests': max_requests})
         wait_until_rpcs_in_flight(int(_WAIT_FOR_STATS_SEC + max_requests / args.qps),
                                   max_requests)
-        wait_until_all_rpcs_fail(int(_WAIT_FOR_STATS_SEC + _NUM_TEST_RPCS / args.qps),
-                                 _NUM_TEST_RPCS)
+        wait_until_all_rpcs_go_to_given_backends_or_fail([], _WAIT_FOR_BACKEND_SEC)
         _assert_rpcs_in_flight(max_requests)
     finally:
         patch_url_map_backend_service(gcp, original_backend_service)