ccrain Posted April 23, 2013 Share Posted April 23, 2013 Well I need to know if you take the pump off a mack how to get it back in timing. My bossman just bought a R model mack wrecker with a holmes 850 on it. It has been sitting for at least 10 years id say. We can not get it to pump fuel. Just curious any suggestion that might get the pump to pump again without removing?? If not he wants to have pump rebuilt but he has never worked on a Mack motor. (he is a expert on cummins 400s and etc.). I will probaley end up doing all the work to the wrecker to get going again though. Its funny he picked the mack up with a ford l-9000 with a 238 detroit (green leaker). Pulled in the yard with the mack, next day cranked ford wrecker up and it run away. Had to pull emergency stop. First thought fuel rack hung but after pulling valve cover surprise. The keepers on one valve come loose and the valve got hung in fuel rack. Anyway he wants to fix the mack. Just a background about myself i have been around trucking all my life. My dad a couple years back drove a ch613 mack with a 400 and 18 speed mack motor/tranny. No one were he worked could shift the mack. My daddy told them a mack transmission is sensitive. Everybody else scrubs every gear. My boss also has a F model mack and H model mack, and a bunch of Kenworths and Freightliners. Quote Link to comment https://www.bigmacktrucks.com/topic/30942-newby-assistance-needed-300-mack-in-r-model/ Share on other sites More sharing options...
j hancock Posted April 23, 2013 Share Posted April 23, 2013 If it has been sitting, the fuel system could be plugged or full of crap or del. hose has collapsed or plugged filters.Start by getting a container of good fuel and connecting a good line to the lift pump. Crack the injector lines at the injector pump and see what you get. Is the fuel coming through the system?Bypass all the easy things such as tanks, filters or anything that could have gone bad in 10 years of sitting. That will give you an idea if the pump does have to come off. Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/30942-newby-assistance-needed-300-mack-in-r-model/#findComment-179969 Share on other sites More sharing options...
oilburner Posted May 4, 2013 Share Posted May 4, 2013 If it is a older style mack and not a e7 you will not get it out of time by taking the pump off as long as you don't pull the front. the pump will only go on one way, but a e7 I leaned the hard way has a different set up with the econvance on them and you can put the pump on sevral ways because it has a splined shaft with a coupler that drives it from the econvane. Before I pulled it I would take j hancocks advice and cover all the bases frist it could just be the lift pump the pulls the fuel to the injector pump. I have seen these engine stick wide open after sitting for a long time, a friend of mine has a r model dump that sit about 2 years and we were going to get it going one spring when we put a battery in it we had a problem with it getting fuel so we put air in the tank and got it up to the pump, as soon as it fired it was wide open we could not kill it with the kill luckly he got it in gear somehow and killed it that way and he has not messed with it since, so check out the simply things before you go pull the pump and when you do get it going be ready for the worst. Good luck Quote Link to comment https://www.bigmacktrucks.com/topic/30942-newby-assistance-needed-300-mack-in-r-model/#findComment-181758 Share on other sites More sharing options...
felicello122 Posted May 4, 2013 Share Posted May 4, 2013 Well I need to know if you take the pump off a mack how to get it back in timing. My bossman just bought a R model mack wrecker with a holmes 850 on it. It has been sitting for at least 10 years id say. We can not get it to pump fuel. Just curious any suggestion that might get the pump to pump again without removing?? If not he wants to have pump rebuilt but he has never worked on a Mack motor. (he is a expert on cummins 400s and etc.). I will probaley end up doing all the work to the wrecker to get going again though. Its funny he picked the mack up with a ford l-9000 with a 238 detroit (green leaker). Pulled in the yard with the mack, next day cranked ford wrecker up and it run away. Had to pull emergency stop. First thought fuel rack hung but after pulling valve cover surprise. The keepers on one valve come loose and the valve got hung in fuel rack. Anyway he wants to fix the mack. Just a background about myself i have been around trucking all my life. My dad a couple years back drove a ch613 mack with a 400 and 18 speed mack motor/tranny. No one were he worked could shift the mack. My daddy told them a mack transmission is sensitive. Everybody else scrubs every gear. My boss also has a F model mack and H model mack, and a bunch of Kenworths and Freightliners.I have a like new pump for the e6 mack, it is a Robert bosh style, try to post the year and model of the motor Quote Link to comment https://www.bigmacktrucks.com/topic/30942-newby-assistance-needed-300-mack-in-r-model/#findComment-181784 Share on other sites More sharing options...
jakebrake86 Posted May 5, 2013 Share Posted May 5, 2013 I'm sure you can get her going. In '07 I drug home a '73 DM that had last been tagged in '87. Had to cut down a 6'' dia. tree growing up through the fender. I ran the fuel line up into a plastic tank in the cab, cracked the injector lines at the pump, and drug it a time or two around the shop until we had fuel. Tightened them down, and other than the turbo being seized, she ran pretty good! Quote Jake Link to comment https://www.bigmacktrucks.com/topic/30942-newby-assistance-needed-300-mack-in-r-model/#findComment-181835 Share on other sites More sharing options...
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