davehummell Posted June 1, 2021 Share Posted June 1, 2021 . Years ago if I remember they were cork? I called Watt's and Cooks no soap any ideas I will have to do something the front spacer for the jake is weeping and making a little mess I would like to get the leak fixed before I go down to Macungie. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/66880-gaskets-valve-cover-for-673/ Share on other sites More sharing options...
Joey Mack Posted June 1, 2021 Share Posted June 1, 2021 P.A.I. makes parts for the 673. I have one in my shop now. I also buy from "AGKits.com". the book i posted was a printout that one of my favorite Mack parts guys printed for me. It's 125 pages.. It is loaded with part numbers, for almost all points on a truck... Joey Mack 1 Quote Link to comment https://www.bigmacktrucks.com/topic/66880-gaskets-valve-cover-for-673/#findComment-474615 Share on other sites More sharing options...
Popular Post JoeH Posted June 1, 2021 Popular Post Share Posted June 1, 2021 We've been using the rubber ones through our mack dealer for a long time, they work fine. The key is don't use anything on them and do not overtorque the bolts. Do not use silicone, do not use high tack. They lubricate the gasket enough so it can shift and slide. Also, overtorquing the bolts distorts the valve cover, making it leak. We have had to straighten ours out a number of times over the years until we figured out the tricks to seal them up nice. 3 Quote Link to comment https://www.bigmacktrucks.com/topic/66880-gaskets-valve-cover-for-673/#findComment-474619 Share on other sites More sharing options...
JoeH Posted June 1, 2021 Share Posted June 1, 2021 We probably have 100k hours on the one truck, 1979 R686ST, with the ENDT676 motor. Still working 5-10 hours a day. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/66880-gaskets-valve-cover-for-673/#findComment-474620 Share on other sites More sharing options...
davehummell Posted June 1, 2021 Author Share Posted June 1, 2021 I got things taken apart and the lower gaskets that go between the block and jake spacer plate were good. I glued the rubber gasket on the spacer with the green cat cement. Both rubber gaskets that went between the jake spacer and the original valve cover were split lengthwise that was were the oil was coming out. I think there is too much pressure on the top gasket and it is splitting them. I'm going to do an experiment and try a different way of sealing the top cover. Quote Link to comment https://www.bigmacktrucks.com/topic/66880-gaskets-valve-cover-for-673/#findComment-474621 Share on other sites More sharing options...
davehummell Posted June 1, 2021 Author Share Posted June 1, 2021 If my memory is right I think you would draw down the three valve cover bolts till they seat against the shoulder on the bolt. Right? Quote Link to comment https://www.bigmacktrucks.com/topic/66880-gaskets-valve-cover-for-673/#findComment-474623 Share on other sites More sharing options...
JoeH Posted June 2, 2021 Share Posted June 2, 2021 No, you take them to the torque setting in the book, no more. Quote Link to comment https://www.bigmacktrucks.com/topic/66880-gaskets-valve-cover-for-673/#findComment-474629 Share on other sites More sharing options...
JoeH Posted June 2, 2021 Share Posted June 2, 2021 Unfamiliar with the cat cement. Proper procedure is to clean everything down, wipe it dry, position gasket, place Jake spacer on, position next gasket, make sure gaskets are properly positioned, set valve cover on, take the three bolts to the torque setting in the book. Quote Link to comment https://www.bigmacktrucks.com/topic/66880-gaskets-valve-cover-for-673/#findComment-474630 Share on other sites More sharing options...
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