The capillary tube is not repairable. You will have to replace the tube and gauge assembly. To do this you need to remove the cluster from the dash. The most difficult part of the operation is re-connecting the oil pressure line to the cluster. When it's out it's helpful to replace the steel line with a plastic one from a 108 car. It is longer and pliable and you can make the connection with the cluster pulled out rather than having to do it from under the dash. I think the temperature capillary is filled with mercury so be careful about coming in contact with it. You should be able to find a cluster for not much money. The part number is on the face at the very bottom.