Master cylinder lid seal 68 dart

Had the save problem with mine. What i ended up doing was getting a pack of make your own gasket and cut out a double gasket and put in between the lid and mc. Something like this
https://www.autozone.com/sealants-g...VEv7jBx10uQSrEAQYASABEgJZxPD_BwE&gclsrc=aw.ds