Dirt Farmer Mechanic Posted January 27 Share Posted January 27 Greetings Good People, I recently acquired a 2002 Mack LE613 E7 with 268,000 miles. Drove it north 400 miles to get it home a few wks ago. I noticed prior to driving that even at idle, there’s a build up of pressure in the cooling system of a few pounds after a few minutes. I didn’t seem to go thru coolant on the 400 mile drive, there’s no coolant in the oil, and zero tendency to overheat. In my automotive world, I’d say early signs of a headgasket. Do I just continue to roll with it for now? should I expect to do a head gasket sooner than later? Is this somewhat normal? Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/ Share on other sites More sharing options...
Solution Joey Mack Posted January 27 Solution Share Posted January 27 With the engine cold, can you fill the tank an inch from the top and run it to see if it purculates in a minute after starting. If you dont have the neat funnel tool, harbor freight had it.. lets fo some diagnosis. Pump cavitation is a thing to consider, nut lets start small.. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-567918 Share on other sites More sharing options...
Dirt Farmer Mechanic Posted January 27 Author Share Posted January 27 24 minutes ago, Joey Mack said: With the engine cold, can you fill the tank an inch from the top and run it to see if it purculates in a minute after starting. If you dont have the neat funnel tool, harbor freight had it.. lets fo some diagnosis. Pump cavitation is a thing to consider, nut lets start small.. Thanks Joey. I do believe that it takes a few min before it begins to build pressure. You mean the funnel extender that seals around the cap? I think I have one. I think I have a block tester and fluid also… 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-567920 Share on other sites More sharing options...
Joey Mack Posted January 28 Share Posted January 28 Yep. Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-567921 Share on other sites More sharing options...
Dirt Farmer Mechanic Posted February 2 Author Share Posted February 2 On 1/27/2025 at 7:03 PM, Joey Mack said: Yep. I added the fancy funnel, topped the level, ran it for about 15 min on Friday when we had a balmy 34°. No gas bubbles of any sort. The volume level tends to rise until i raise the RPM, at which point it goes down. I see no point on fretting any further at this time. Thanks for that recommendation. I like the feeling of greater certainty. Joey, do you have any scanner recommendations? I use a Snapon Modis for cars but I don’t think I want that for this or future Macks. Suggestions welcome. Cheers Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-568373 Share on other sites More sharing options...
Joey Mack Posted February 2 Share Posted February 2 The technology has gotten far away from me. I guess it depends on what you intend to use it for, and the model years of the trucks you work on.. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-568376 Share on other sites More sharing options...
Dirt Farmer Mechanic Posted February 2 Author Share Posted February 2 4 hours ago, Joey Mack said: The technology has gotten far away from me. I guess it depends on what you intend to use it for, and the model years of the trucks you work on.. for starters, the aforementioned 2002. But I expect to have to purchase newer versions (still at least 10+ yrs old but similar E techs or MP7s?) since 2002 and older are hard to find. Usage would be scanning/clearing codes in engine, abs, trans, reading live data, and possible connectivity for deletions with newer trucks that I don’t have at this time. The last is less important at this time. I hear the tech bit. I appreciate your time and don’t want to force an answer Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-568435 Share on other sites More sharing options...
Joey Mack Posted February 2 Share Posted February 2 If you post the truck models/years etc... someone will help you. JoeH may know, he is a currently active mechanic. Mackpro is another who may help. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-568436 Share on other sites More sharing options...
Joey Mack Posted February 2 Share Posted February 2 Ok.. I have gotten pretty good with Premium Tech Tool when i was a full time mechanic. The communication box is expensive. Do you have any form of a laptop, or comm box? Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-568437 Share on other sites More sharing options...
Dirt Farmer Mechanic Posted February 2 Author Share Posted February 2 I have a laptop that I run my VW aftermarket program on. Also, an older BOSCH VCI interface “box” that I’ve used to flash GMs. I don’t think it runs the same protocol tho? Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-568458 Share on other sites More sharing options...
Joey Mack Posted February 2 Share Posted February 2 I dont know what to suggest for you at this point. I wish I did.. if you are messing with deleted big trucks, you may be asking for trouble when it comes to satisfying a customer who doesnt understand the effort you have to do to beat out the government issued B.S. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75079-pressure-in-cooling-system/#findComment-568466 Share on other sites More sharing options...
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