As long as tool is working normally and you just can't get the spring compressed quite enough then my observations from having just rented the tool are; I found that you can't slide the metal plate into the very top spring coil, because it is too tight. But you kind of have to get it in there in order to get enough compression. If you put the plate in a lower coil and rotate it around the spring you can get it at the very top. Also it is hard to get the spring out with the pad on it. I don't know if your car has spring pads but mine were huge. They screw/twist on so if you unscrew from top of spring you have a lot more clearance to get the spring out. HTH