JoeH Posted March 17, 2022 Share Posted March 17, 2022 We have had this truck for 10+ years, and have never seen much boost pressure out of it. It briefly hits 23 psi at 1700 rpms, but more than 50 rpms one way or the other and it drops to 20. It gets where it's going, but I'm used to 25 psi from 1200 rpms to 2100 on our endt676 motors. Is my '95 about right? Doesn't smoke, idles clean. 22k+ hours on it, 276k miles. It's a concrete truck, lots of local operating time with minimal mileage. Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/ Share on other sites More sharing options...
JoeH Posted March 17, 2022 Author Share Posted March 17, 2022 Jake brake is also an absolute joke. Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492461 Share on other sites More sharing options...
fjh Posted March 17, 2022 Share Posted March 17, 2022 11 minutes ago, JoeH said: Jake brake is also an absolute joke. yup 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492465 Share on other sites More sharing options...
fjh Posted March 17, 2022 Share Posted March 17, 2022 (edited) 21 minutes ago, JoeH said: We have had this truck for 10+ years, and have never seen much boost pressure out of it. It briefly hits 23 psi at 1700 rpms, but more than 50 rpms one way or the other and it drops to 20. It gets where it's going, but I'm used to 25 psi from 1200 rpms to 2100 on our endt676 motors. Is my '95 about right? Doesn't smoke, idles clean. 22k+ hours on it, 276k miles. It's a concrete truck, lots of local operating time with minimal mileage. 350 mechanical! ! first check to see if the fuel shut off is going full off then check the the throttle lever for full stroke ! All Good? yes !? then Remove the 3/8 plastic line to the top of the fuel pump if u suck on that hose and it won't hold a vacuum the diaphragm in that unit is holed needs replacing! just three quick checks to start with! Edited March 17, 2022 by fjh Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492466 Share on other sites More sharing options...
JoeH Posted March 17, 2022 Author Share Posted March 17, 2022 Sorry that's in the topic title. E7-350 mechanical. 1995. Eaton 8ll. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492468 Share on other sites More sharing options...
fjh Posted March 17, 2022 Share Posted March 17, 2022 (edited) 6 minutes ago, JoeH said: Sorry that's in the topic title. E7-350 mechanical. 1995. Eaton 8ll. check the above first easy stuff! keep us posted! Yup I edited my reaction I noticed the mechanical after the fact ! My bad! Edited March 17, 2022 by fjh Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492470 Share on other sites More sharing options...
John3406 Posted March 18, 2022 Share Posted March 18, 2022 Bosch pump? Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492521 Share on other sites More sharing options...
Dirtymilkman Posted March 19, 2022 Share Posted March 19, 2022 Pressure check intake and cac. You are probably pushing boost out you cac. My 350 mechanical always hit 31 psi Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492663 Share on other sites More sharing options...
JoeH Posted March 20, 2022 Author Share Posted March 20, 2022 23 hours ago, Dirtymilkman said: Pressure check intake and cac. You are probably pushing boost out you cac. My 350 mechanical always hit 31 psi I do hear a boost leak on occasion. Doesn't always do it, but sometimes there's a faint audible leak that builds with the turbo. Is there a particular engine degree to close off enough valves that the pressure test won't leak through the valves? Also, how do you close off the CAC turbo-side? This truck also has a Cold Start bypass setup to bypass the CAC. It has a small crossover pipe coming from between the turbo and CAC with an air operated butterfly valve, and another butterfly valve after the CAC. This system effectively shuts off air flow through the CAC so it sucks in warm turbo air. Is it common for the cold start plumbing to generate a leak? Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492749 Share on other sites More sharing options...
JoeH Posted March 20, 2022 Author Share Posted March 20, 2022 (edited) Boost leak would also explain why this truck runs hot on the pyro, even though it ever smokes... Not hard to hit 1100°+ climbing a hill, even with 4 inch straight through muffler. Edited March 20, 2022 by JoeH Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492750 Share on other sites More sharing options...
terry Posted March 20, 2022 Share Posted March 20, 2022 if you hear a boost leak, you probably have found your problem! terry 2 Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492767 Share on other sites More sharing options...
Popular Post Hans Remmers Posted March 20, 2022 Popular Post Share Posted March 20, 2022 PVC caps are the simplest charge air testing tool. Just install a tr572 or similar valve stem in one. Install the caps in your hoses on the CAC pipes and fill with a tire chuck carefully. Check the cold start valves too to ensure are staying open and closed as req. Air cylinder springs will break. Those systems double the amount of places for boost leaks. 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492774 Share on other sites More sharing options...
fjh Posted March 21, 2022 Share Posted March 21, 2022 (edited) On 3/19/2022 at 8:17 PM, JoeH said: Boost leak would also explain why this truck runs hot on the pyro, even though it ever smokes... Not hard to hit 1100°+ climbing a hill, even with 4 inch straight through muffler. yup! totally agree check the hose at the compressor very common leak there! also have seen these bypass dodads stick! Always by passing the charge air will cause high heat and low power! Most of the engines in our area here we disabled this unit it causes more trouble than its worth! Edited March 21, 2022 by fjh Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492821 Share on other sites More sharing options...
JoeH Posted March 21, 2022 Author Share Posted March 21, 2022 (edited) Charge air cooler leaks like a sieve. Bergeys put in a request to Mack to see if it's available, if it's not then what are my options? RD688S chassis. Edited March 21, 2022 by JoeH Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492862 Share on other sites More sharing options...
theakerstwo Posted March 21, 2022 Share Posted March 21, 2022 (edited) Were i live there is a store that rebuilds them.They can recore them like a rad. Edited March 21, 2022 by theakerstwo Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492873 Share on other sites More sharing options...
Joey Mack Posted March 21, 2022 Share Posted March 21, 2022 we have radiator repair shops that can fix'em ,, jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492884 Share on other sites More sharing options...
JoeH Posted March 22, 2022 Author Share Posted March 22, 2022 The guy near us closed up his radiator repair and shifted to selling welding supplies. Nowadays radiators are plastic throw-aways, not much business in repair. I'll call him tomorrow and see if he's willing/able. Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492900 Share on other sites More sharing options...
theakerstwo Posted March 22, 2022 Share Posted March 22, 2022 1 hour ago, JoeH said: The guy near us closed up his radiator repair and shifted to selling welding supplies. Nowadays radiators are plastic throw-aways, not much business in repair. I'll call him tomorrow and see if he's willing/able. A few years back a friend of mine had a rad shop for years and his dad did before him.But the cheapo rads was not repairable so he saw the light.He could build custom rad to fit any thing and his replacement cores was made from copper but it got were you could buy a new cheapo cheaper.My CH needed a rad and from mack i paid little over 800.00 for a new one then i open it up and its Aluminium with plastic tanks. 1 Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492906 Share on other sites More sharing options...
JoeH Posted March 22, 2022 Author Share Posted March 22, 2022 Bergeys has access to it, it'll be here in about a week. Anxious to see what 350hp feels like, this truck has always run a little hot on the pyro with no more than 25 psi boost. Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-492940 Share on other sites More sharing options...
JoeH Posted March 31, 2022 Author Share Posted March 31, 2022 Truck went from being a mutt tapping out barely at 20 psi of boost back to a bulldog at 30 psi of boost. In 10 years of owning this truck we have never seen more than 25 psi out of it. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-493997 Share on other sites More sharing options...
terry Posted March 31, 2022 Share Posted March 31, 2022 10 minutes ago, JoeH said: Truck went from being a mutt tapping out barely at 20 psi of boost back to a bulldog at 30 psi of boost. In 10 years of owning this truck we have never seen more than 25 psi out of it. What did you fix? terry Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-494000 Share on other sites More sharing options...
JoeH Posted March 31, 2022 Author Share Posted March 31, 2022 Replaced charge air cooler. Had a fatigue crack halfway down the front of one side. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-494010 Share on other sites More sharing options...
Joey Mack Posted March 31, 2022 Share Posted March 31, 2022 I see a lot of them crack on the top right corner and run down. glad its fixed.. jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-494011 Share on other sites More sharing options...
JoeH Posted April 1, 2022 Author Share Posted April 1, 2022 The top "right" (passenger side) bolt must have dropped the rubbery washer out. That bolt wasn't holding that corner down well, but the bolt was seized: twisted off. Had to drill and re-tap to take a 5/16 bolt instead of the metric junk that was in there. Only got to do a 4 mile round trip test run empty today, looking forward to seeing how it runs loaded tomorrow! 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-494051 Share on other sites More sharing options...
JoeH Posted April 1, 2022 Author Share Posted April 1, 2022 Also the pyrometer is now running 2-300° cooler. Quote Link to comment https://www.bigmacktrucks.com/topic/69394-95-e7-350-mechanical/#findComment-494107 Share on other sites More sharing options...
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