Air carrier Maintenance Technician reported gate return of aircraft due to parking brake anomaly.

Narrative

Aircraft X was a gate return before take off. ref Logbook Deferral Sheet# XXXXXXX the pilot set the parking brake and noticed the plane's brake pressure indicated that the pressure went to 0 briefly and came back. During that event (which was not in the write up) the planed moved with the brake set. Normal braking was fine. Aircraft has history on this.Cause: The mechanics and avionics were troubleshooting the problem using the Trouble Shooting Manual (TSM) and wiring diagram. The troubleshooting started at the end of day shift. Afternoon shift supervisor Person A was on shift for afternoon. Person A kept stressing that the job wasn't moving fast enough. He wanted to know what was taking so long and said 9 times out of 10 changing parts fixes the problem. I let him know the job takes as long as it takes and we were working on it. I had conferred with Maintenance Control and had a verbal agreement on the path to take to resolve the problem. When Person A would not stop about the job I asked him are you directing me to have the mechanics change a valve and switch without completing the TSM? Avionics had cannon plugs off at the time and were doing wiring checks. He said yes. I repeated myself. Are you directing me to tell the mechanics to change the parts even though we have not finished troubleshooting and I think that this is a bad idea at this point. He again said yes and walked out to go to his meeting. This is common from Person A and others on afternoon/overnight shift to pressure mechanics. Person A specifically said he is tired of getting yelled at during the evening meetings. I offered to go with him and he said no. Person A says he gets yelled at a lot.Suggestions: I believe this is dangerous behavior from management. We have many times in the past asked them not to pressure. Person B has covered this with upper ZZZ management before. As far as this afternoon shift goes; nothing has changed. Day shift is starkly different than afternoon and midnight shifts. To direct mechanics to start changing parts while another work group is working the same system is irresponsible and dangerous and could get someone hurt. This has got to stop. We are here to troubleshoot and find the problem.