diff --git a/clearml_serving/serving/model_request_processor.py b/clearml_serving/serving/model_request_processor.py
index 98f8b0d..49de499 100644
--- a/clearml_serving/serving/model_request_processor.py
+++ b/clearml_serving/serving/model_request_processor.py
@@ -168,6 +168,8 @@ class ModelRequestProcessor(object):
             # retry to process
             return await self.process_request(base_url=base_url, version=version, request_body=request_body)
 
+        processor = None
+        url = None
         try:
             # normalize url and version
             url = self._normalize_endpoint_url(base_url, version)
@@ -189,6 +191,9 @@ class ModelRequestProcessor(object):
 
             return_value = await self._process_request(processor=processor, url=url, body=request_body)
         finally:
+            if url and processor is not None and processor is not self._engine_processor_lookup.get(url):
+                self._report_text("calling gc collect in request processing")
+                gc.collect()
             self._request_processing_state.dec()
 
         return return_value
@@ -906,6 +911,8 @@ class ModelRequestProcessor(object):
                 if cleanup or model_monitor_update:
                     self._update_serving_plot()
                 if cleanup:
+                    self._report_text("calling gc collect in cleanup")
+                    gc.collect()
                     self._engine_processor_lookup = dict()
             except Exception as ex:
                 print("Exception occurred in monitoring thread: {}".format(ex))
@@ -914,23 +921,16 @@ class ModelRequestProcessor(object):
             self._report_text("after sleep")
             try:
                 # we assume that by now all old deleted endpoints requests already returned
-                self._report_text("model_monitor_update and not cleanup")
+                call_gc_collect = False
                 if model_monitor_update and not cleanup:
-                    self._report_text("for k in list(self._engine_processor_lookup")
                     for k in list(self._engine_processor_lookup.keys()):
-                        self._report_text(f"if k now in self._endpoints {self._endpoints} {k}")
                         if k not in self._endpoints:
                             # atomic
-                            self._engine_processor_lookup[k]._model = None
-                            gc.collect()
-                            self._report_text(str(self._engine_processor_lookup[k]._preprocess))
-                            self._report_text(dir(self._engine_processor_lookup[k]._preprocess))
-                            if hasattr(self._engine_processor_lookup[k]._preprocess, "unload"):
-                                try:
-                                    self._engine_processor_lookup[k]._preprocess.unload()
-                                except Exception as ex:
-                                    print("Exception occurred unloading model: {}".format(ex))
                             self._engine_processor_lookup.pop(k, None)
+                            call_gc_collect = True
+                if call_gc_collect:
+                    self._report_text("calling gc collect in try")
+                    gc.collect()
                 cleanup = False
                 model_monitor_update = False
             except Exception as ex:
diff --git a/clearml_serving/serving/preprocess_service.py b/clearml_serving/serving/preprocess_service.py
index a5c069c..81d4926 100644
--- a/clearml_serving/serving/preprocess_service.py
+++ b/clearml_serving/serving/preprocess_service.py
@@ -90,7 +90,15 @@ class BasePreprocessRequest(object):
             sys.modules[spec.name] = _preprocess
             spec.loader.exec_module(_preprocess)
 
-        Preprocess = _preprocess.Preprocess  # noqa
+        class PreprocessDelWrapper(_preprocess.Preprocess):
+            def __del__(self):
+                super_ = super(PreprocessDelWrapper, self)
+                if callable(getattr(super_, "unload", None)):
+                    super_.unload()
+                if callable(getattr(super_, "__del__", None)):
+                    super_.__del__()
+
+        Preprocess = PreprocessDelWrapper # noqa
         # override `send_request` method
         Preprocess.send_request = BasePreprocessRequest._preprocess_send_request
         # create preprocess class