Bill and Mark are correct about the push rod tool compression tool. It was for /5s only, I thought. If used on tubes that have the attached metal rings the tube gets pulled out of the head. Sometimes the fit of the tube is ruined by doing this and then you have an oil leak from the bottom side of the head.
If it is done once it sometimes causes no problems but the rubbers will leak again and the tool will be used over and over. then you will have problems. Fix the rubbers. Replace them.