teleman Posted June 7, 2010 Share Posted June 7, 2010 Last week it started right up,held good oil pressure and had good throttle response and ran smooth then after a while started to stumble then quit.I figured it picked up some dirt.Sunday I went thru it again and took all the lines on the low side loose and blew thru them,blew from the primary filter back to the tank and could here it bubble,cleaned both filters and refilled with fuel.I expected to find some dirt but filters were clean but 1/2 full and fuel was discolored so it must have pulled from the tank at least a little bit.Anyway pumped it up again and hit the button...she fired right off and ran like before then in a while started to stumble then quit?Im thinking maybe its running on the fuel in the filters and not pulling enough from the tank?with the filters half full maybe I need to keep bleeding the line on top of the filter longer(thats scary,Im answering my own questions)I couldnt find anything that looked like an air bleed.Next time Im going to take the fuel cap off the tank in case vent is clogged?Im going to go thru it again but its been raining so Ive been thinking about what steps to take next!I know we are getting clean fuel,the suction side lines are clear,it must have pulled some fuel from the tank because the fuel in the filter was discolored the first time,I drained and cleaned tanks,I closed the crossover valves to the right tank for now?the primer pump worked but never really got a hard feel out of it,I think I should check for leaks on suction side where it could pull air,should there be a check valve somewhere to keep fuel from running back...looking for ideas...Thanks...thats alot of questions....Jim Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/ Share on other sites More sharing options...
fjh Posted June 7, 2010 Share Posted June 7, 2010 Last week it started right up,held good oil pressure and had good throttle response and ran smooth then after a while started to stumble then quit.I figured it picked up some dirt.Sunday I went thru it again and took all the lines on the low side loose and blew thru them,blew from the primary filter back to the tank and could here it bubble,cleaned both filters and refilled with fuel.I expected to find some dirt but filters were clean but 1/2 full and fuel was discolored so it must have pulled from the tank at least a little bit.Anyway pumped it up again and hit the button...she fired right off and ran like before then in a while started to stumble then quit?Im thinking maybe its running on the fuel in the filters and not pulling enough from the tank?with the filters half full maybe I need to keep bleeding the line on top of the filter longer(thats scary,Im answering my own questions)I couldnt find anything that looked like an air bleed.Next time Im going to take the fuel cap off the tank in case vent is clogged?Im going to go thru it again but its been raining so Ive been thinking about what steps to take next!I know we are getting clean fuel,the suction side lines are clear,it must have pulled some fuel from the tank because the fuel in the filter was discolored the first time,I drained and cleaned tanks,I closed the crossover valves to the right tank for now?the primer pump worked but never really got a hard feel out of it,I think I should check for leaks on suction side where it could pull air,should there be a check valve somewhere to keep fuel from running back...looking for ideas...Thanks...thats alot of questions....JimThere should be a drain back valve on the fuel pump it will have a small 1/4 inch line going up to the head and the other goes to the fuel tank if you remove the top of that valve and check the spring you may find it broken!You may also have a failing fuel transfer pump or a perforated suction line to the tank!I would fill the filters with clean fuel the next time you try to start pumping takes for ever! Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-56735 Share on other sites More sharing options...
Mike Posted June 7, 2010 Share Posted June 7, 2010 Jim, Are you sure your bleeding all the air out of the fuel lines? And letting fuel pour out the line you are bleeding while running then put the line back on while the truck is running. I hope that made sense. I have seen where blowing compressor air into the tank helps to. mike Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-56738 Share on other sites More sharing options...
teleman Posted June 7, 2010 Author Share Posted June 7, 2010 Thanks fjh.I will check that out and yes I fill both filters up before pumping.That brings another question about the secondary filter housing...the top cover has a big nut on top with a brass fitting coming out of it and that line goes to the return fitting on the side of the pump...should that nut have a gasket under it?you can pull the nut up against the spring tension and it looks like maybe there was red permatex under the nut but not sure??? Thanks Jim Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-56739 Share on other sites More sharing options...
teleman Posted June 7, 2010 Author Share Posted June 7, 2010 Thanks Mike.I fill the filters then pump and it fires right up and runs smooth and has good throttle response.It seems like its running on the fuel I put in the filters then quits.Then I check the filters and they are half full...It makes sense that Im not bleeding it in the right place or bleeding it enough like you said so maybe tonight I can try it again...Jim Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-56740 Share on other sites More sharing options...
bullhusk Posted June 7, 2010 Share Posted June 7, 2010 Make sure your vent tubes on top of your fuel tank are clear. Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-56743 Share on other sites More sharing options...
Mike Posted June 7, 2010 Share Posted June 7, 2010 Thanks Mike.I fill the filters then pump and it fires right up and runs smooth and has good throttle response.It seems like its running on the fuel I put in the filters then quits.Then I check the filters and they are half full...It makes sense that Im not bleeding it in the right place or bleeding it enough like you said so maybe tonight I can try it again...Jim Jim, Not saying this is the cure but, I bled mine from the top hose while the engine is running and a solid stream of fuel is flowing and screwed the hose onto its fitting. The book says the hose on the side of the secondary filter is the fuel inlet and the outlet is under the filter housing. The one on top is the air bleed hose although fuel goes through it when properly done. mike Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-56751 Share on other sites More sharing options...
fjh Posted June 7, 2010 Share Posted June 7, 2010 Jim, Not saying this is the cure but, I bled mine from the top hose while the engine is running and a solid stream of fuel is flowing and screwed the hose onto its fitting. The book says the hose on the side of the secondary filter is the fuel inlet and the outlet is under the filter housing. The one on top is the air bleed hose although fuel goes through it when properly done. mikeSounds to me like the transfer pump is fubar! Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-56760 Share on other sites More sharing options...
teleman Posted June 14, 2010 Author Share Posted June 14, 2010 Hey everybody,our next to youngest boy graduated college Saturday so Im finally done with that "honey do list" getting ready for the party...now I can work on the Mack again.I went over everything again before I pumped it up and guess what...the one line I didnt check before,the return line,I could not blow air thru it...took the fuel cap loose,blew again and its clear...yep vent tube clogged.Bullhusk called it... so I cleaned the vent tube(that was hard to get to)bled it again like Mike said and she started right up and this time kept running.I let her run and when I came back from walking into the house for some water,she was still running ,had 90 lbs air and the wipers were working.I pinched off the RR brake line (leaking) with vise grips and it built up to 120lbs.I guess Im amazed that after sitting all those years everything still works or is at least trying to work.I backed off the brakes a little as the shoes were stuck to the drums and now it has some brakes.Worst part is the brake pedal was frozen so Ive been using PB blaster on it.If that had been free I would have at least run it down the road and back...boy was it tempting...Thanks Jim Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-57302 Share on other sites More sharing options...
Mike Posted June 14, 2010 Share Posted June 14, 2010 Jim, That sounds like a wiener to me. Be sure to get it past the driveway and not run out of fuel ( THE FUEL PHANTOM ) lurks again. Let us know how it shifts and drives. My regards mike Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-57303 Share on other sites More sharing options...
Greg Rider Posted June 14, 2010 Share Posted June 14, 2010 I don't live too far away from you. I am in Brewster on the south side of town. E-mail me your address and I might swing by with Faith someday. Glad to hear the B is doing better. Quote #1 on A-model registryIf I drink because of work, why can't I drink at work? Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-57318 Share on other sites More sharing options...
teleman Posted June 21, 2010 Author Share Posted June 21, 2010 Went out this morning and started her up after sitting for a few days...listening to her run and checking for leaks I was overcome by this crazy "I should know better urge" but I backed her out on the road anyway and took her for a quick test run.That was so neat now I want more......Jim Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-57884 Share on other sites More sharing options...
Freightrain Posted June 21, 2010 Share Posted June 21, 2010 ......I was overcome by this crazy "I should know better urge" but I backed her out on the road anyway and took her for a quick test run.That was so neat now I want more......JimAhhh, the sickness is festering................LMAO!!!Welcome to the club! Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-57886 Share on other sites More sharing options...
Mike Posted June 21, 2010 Share Posted June 21, 2010 Good to hear it's still running. Hmmm are you sure you turned the ignition off?.....Cause I believe I hear it still running. There is three distinct sounds of an engine that i'm used to hearing which is. 1. Straight pipe B Model Mack 2. Rolls Royce Merlin 12 Cylinder out of a P51 Mustang Fighter Plane 3. Top Fuel Dragster on Nitro Methane Fuel And I like all three of them. Keep us posted with photos mike Quote Link to comment https://www.bigmacktrucks.com/topic/14239-started-right-upbut/#findComment-57891 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.