Jamied625 Posted July 27, 2015 Share Posted July 27, 2015 I have a 95 r model tri axle dump with a e 7 that has had a over heating issue for a while did a radiator then fan clutch then water pump and thermostat. Each time I did one of these things problem seemed to go away for few days. With in a minute of start up at 1000 rpm it made 21 psi in cooling system. Somebody have any ideas. ThanksJamie Quote Link to comment https://www.bigmacktrucks.com/topic/41110-e-7-pressuring-coolant/ Share on other sites More sharing options...
alex g Posted July 28, 2015 Share Posted July 28, 2015 Head gasket? Quote Link to comment https://www.bigmacktrucks.com/topic/41110-e-7-pressuring-coolant/#findComment-298121 Share on other sites More sharing options...
gearhead204 Posted July 28, 2015 Share Posted July 28, 2015 faulty air compressor? Quote Link to comment https://www.bigmacktrucks.com/topic/41110-e-7-pressuring-coolant/#findComment-298127 Share on other sites More sharing options...
Solution turckster Posted July 28, 2015 Solution Share Posted July 28, 2015 Cracked head(s) or bad air compressor. Isolate the cooling system from the air compressor, run the engine and see if the system still builds pressure quickly. If it does the you have a cracked head or blown head gasket, most likely a cracked head(s). These heads do not tolerate excessive heat, if one is cracked our policy is to replace both heads. The obvious cracks will be between valves or between injector hole and valves, its the cracks you won't see that will get you-inside injector sleeve at the tip sealing area, inside or around a valve seat and so forth. With it building pressure so quick it should be obvious. A head gasket is a possibility as well but with overheating it is usually a cracked head. Quote Link to comment https://www.bigmacktrucks.com/topic/41110-e-7-pressuring-coolant/#findComment-298187 Share on other sites More sharing options...
Jamied625 Posted July 31, 2015 Author Share Posted July 31, 2015 Thanks for you he help I isolated the air compressor and still had pressure so the heads are coming off now. Any tips or secrets to a e7 head job? Done a bunch of cats and cummins but no macks yetthanksJamie Quote Link to comment https://www.bigmacktrucks.com/topic/41110-e-7-pressuring-coolant/#findComment-298549 Share on other sites More sharing options...
alex g Posted July 31, 2015 Share Posted July 31, 2015 I have a brand new set of heads here in mack boxes that I'm told are E7 heads if your in need of one or two and there the same PM meSent from my SM-G386W using Tapatalk Quote Link to comment https://www.bigmacktrucks.com/topic/41110-e-7-pressuring-coolant/#findComment-298594 Share on other sites More sharing options...
turckster Posted August 1, 2015 Share Posted August 1, 2015 Thanks for you he help I isolated the air compressor and still had pressure so the heads are coming off now. Any tips or secrets to a e7 head job? Done a bunch of cats and cummins but no macks yetthanksJamieIts not much different than others, a few things to keep in mind though. There were some years of the e-7(early 90's) that had 2 types of liner fire rings- a stepped ring and a flat ring. You can not mix these fire rings so make sure you replace with what the liner is set up for. Make sure that the head bolt threads and threads in the block are clean. Apply oil to the head bolt threads and washers. Before torquing the head bolts the heads must be aligned. Using a long straight edge, alight the exhaust side of the heads-the rear side of each head will pivot slightly.Any questions, just ask . Good luck Quote Link to comment https://www.bigmacktrucks.com/topic/41110-e-7-pressuring-coolant/#findComment-298658 Share on other sites More sharing options...
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