Komatsu Dozer wont start

[KyleB83]

This piece of junk primer pump took a crap as well... I am not priming it fast and when I feel resistance I stop. Where can I get one that won’t die after one use?

 

[thepumpguysc]

HOW is it "bad".?? its simply a rod w/ a piece of rubber on the end..
U probably have other problems..
The primer should be able to pump fuel from the fuel tank, up to the injection pump & pump enough fuel pressure to pop of the overflow valve..
Pull off the return line on the inj. pump & SEE whats happening..
Are u sure u put the HP on the right side.??

 

[KyleB83]

is it not spring loaded? something inside binds up and it will no longer pump.. even off of the machine with nothing to give any back pressure I can not press the primer down. I am going to put pressure to the tank and just start cracking lines in order until I get back to the injectors. I still have a feeling there is some trash that either settles in the tank or some trash somewhere in the system that works its way to a clog.

 

[Sawyer Rob]

I am going to put pressure to the tank and just start cracking lines in order until I get back to the injectors.

About time! lol

SR

 

[KyleB83]

Man I tried that a week or so ago and got absolutely nothing any farther than the hand primer... what I meant to say was I hate this effing dozer lol

 

[thepumpguysc]

U aren't gonna get fuel TO the injectors w/o the pump spinning..
The inj. pump operates the lift pump off a cam inside the inj. pump..
The lift pump has valves in it..
ALL the lift pump does is suck fuel from the tank & PUSHs it to the inj. pump fuel gallery.
The inj. pump takes the fuel from the gallery & pumps it to the injectors.. it returns the unused fuel & PRESSURE from the lift pump, thru an overflow valve on the return hose connected to the inj. pump..
SO, that's 2-3 "BAD" hand primers. REALLY.??

 

[KyleB83]

if not, i am all ears to what else could cause 2 primers to pump fine a few times then bind up to where I cant get them to pump again. without the primer even on the machine, I can not press down on it

 

[finn1]

The primer pumps fuel to the filter and injection pump. The injection pump has retraction valves on top of the plungers that won’t pass fuel to the injection lines at the low pressure that the hand primer generates.

If the hand primer is “bound up”, it sounds like you have fuel to the injection pump gallery, and nothing is wrong with the primer. The sole purpose of the hand primer is to allow one to bleed air from the filter after a filter change. Tru opening the bleed valve on the filter and you should get air and fuel flowing out the valve when you cycle the hand primer.

 

[KyleB83]

ok so in theory... if I pressurize the tank, and have someone cranking the engine, I should be able to bleed all the way up to the injectors correct?

 

[Sawyer Rob]

I pressure the fuel tank and bleed air out, at the back of the injection pump. IF, fuel doesn't pour out of that line, then there's something blocking it from getting there. Then, I crack a couple lines at the injectors, and crank it over to bleed the air from the injection pump to the injectors... The engine may/probably will start on what ever cylinders that you didn't open the lines to.

As a side note: one time my dozer wasn't running right and I changed the fuel filters, it didn't help. Then I found a "small" screen "in" the pump at "inlet" of it! I took it out and it looked clean, BUT I washed/brushed it good, blew it out with air pressure, reinstalled it and the dozer has run fine ever since!

SR