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My 79 r model won’t start.It has been hard starting if it sit for a while,like it loses it prime.Now it won’t start at all.Checked the filter it’s fill of fuel.It will start on starting fluid but won’t run on it own.The hand priming pump,I pump it like 50 times and it doesn’t get hard.I’m thinking it may be bad,anyone know the part number for will change it out.Any help would be most helpful.Thanks.Mike Durkin.

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Could be a leak in the fuel line on the suction side. Wont leak fuel but will suck air and prevent startup. The first thing I would do is put a fuel line from the filter housing to a jerry can of fuel and try it. If still no start then put a clear fuel line between the filter housing and injection pump and watch for air when you try to start it. Diesels are pretty simple, if it's getting fuel it's gotta go. Pooched hand pump shaped not affect it's ability to run and will only prevent you from priming the system and if the system lost it's prime, you have other issues. You could put an electric fuel pump in your temp line from the jerry can to eliminate the need for the hand pump. 

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27 minutes ago, Red Horse said:

If pumping primer 50 times and it doesn't build pressure what does that say.? 

It says that it isn't working properly😋. When I had a no start on my '98 WS (550 CAT) it was a check valve in the filter housing. When I had a no start on my '05 Pete (475 CAT) it was a loose fitting on a fuel line on the suction side allowing air into the system. IIRC, it both cases the hand primer would not build pressure. 

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1 hour ago, Licensed to kill said:

It says that it isn't working properly😋. When I had a no start on my '98 WS (550 CAT) it was a check valve in the filter housing. When I had a no start on my '05 Pete (475 CAT) it was a loose fitting on a fuel line on the suction side allowing air into the system. IIRC, it both cases the hand primer would not build pressure. 

that was the point I was trying to make.  My 237 has always started at touch of button.  But in process of replacing steering box I took the primary off for better access.  In process of pulling floor boards up, I lost a piece of throttle linkage so I made up new rod.  I had all floor back in place  and wanted to make sure linkage was good so I fired it up-after making sure primary was full.  Ran for a few minutes then quit.  Cranking and no smoke.  Pulled primary and it was down well below pick up.  Not being a "wrench" I filled it again with same result.  And this was after I disconnected outlet at second filter just before pump.  Hit the primer about 8 times got good pressure and I'm spraying fuel-again primary was full to brim t that point..  Filled it again, fired up, running well and I then shut it down and pulled primary.  Sure enough it is NOT full.  Called my "mentor" Danny M-Mass guys will know who I'm talking about-He quickly says I have a leak in line between tank and filter.  I say.."but I checked line-no evidence"-he says "Its a suction line-its an air leak.  "Check line again"..... Duh- took me 3 seconds- I 'm looking at filter housing and I see like 3 bright brass threads on hose! 

In process of taking filter off, I disconnected housing from firewall and in process of wrestling old box out and putting replacement in the real mechanic who was helping me and I kept moving fuel line/filter base and obviously loosened hose.

Now I know what an air leak can do to a pump😎

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4 hours ago, Red Horse said:

If pumping primer 50 times and it doesn't build pressure what does that say.? 

I had to fix the hand pump on my 237 before getting it running the first time after buying it.   There is basically two ceramic discs with springs behind them that act like one way valves.  Mine were dried up and stuck.  Once I lubed them the hand pump works flawless.

I'm not sure "IF" they have any affect on running?  Never found out.  Just have to unscrew the two plugs and see what you find.  I wonder if the return side was stuck open, would that allow fuel to drain off after shutting it off?  I know with the truck running, if you leave the hand pump loose it will pump up/down while the engine is running.  I've never ran it long like that so can't say if it detrimental to fuel pressure/power?

IMG-20180116-202556-655.jpg

Larry

1959 B61 Liv'n Large......................

Charter member of the "MACK PACK"

 

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5 hours ago, Freightrain said:

I had to fix the hand pump on my 237 before getting it running the first time after buying it.   There is basically two ceramic discs with springs behind them that act like one way valves.  Mine were dried up and stuck.  Once I lubed them the hand pump works flawless.

I'm not sure "IF" they have any affect on running?  Never found out.  Just have to unscrew the two plugs and see what you find.  I wonder if the return side was stuck open, would that allow fuel to drain off after shutting it off?  I know with the truck running, if you leave the hand pump loose it will pump up/down while the engine is running.  I've never ran it long like that so can't say if it detrimental to fuel pressure/power?

FT-thx for prime pump lesson!

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Got the new one in and the old dog still won’t fire,so after some choice words that we won’t mention here.I bypass the new pump and the filters and tried starting out of a can full of fuel.Runs like a Swiss watch.New pump is bad,that’s what I get for being cheap.Macks new one was $210 pai was $139,going to get a Mack one.

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I thought about just by passing the damn thing I really don’t need it anyway but it is handy to have .... all my lines need to be changed But I will certainly try that before..... but mine is a lot easier to get to .. bob

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