Case 850 D needs to be bled every morning

jamesh · Oct 21, 2018

My 850 Case dozer has fuel problem that is driving me crazy.My tractor will start up every morning and idle for hours if I let it.I go to take off and it dies.No fuel.I bleed the injectors and it fires right back up.Run it for a little bit and it dies again.Bleed it again and it will run fine all day even if I shut it down for an hour or more.I've replaced the lift pump,fixed a small leak in the fuel line,drained and bled the fuel filter.Is my injector pump going out or am I missing something?

Dieseltech · Oct 21, 2018

Sounds like it's getting air in the system. What engine and injection pump does it have? Will it act up with a full tank of fuel?

jamesh · Oct 21, 2018

It has a 6T-590 cummins diesel engine with a Bosch injector pump

Dieseltech · Oct 21, 2018

Which Bosch pump, rotary VE or inline A size?

Dieseltech · Oct 21, 2018

The 850D parts list I found shows non turbo engines use the CAV DPA rotary pump, turbo engines use the Bosch VE rotary pump. CAV DPA pumps have a two bolt side cover to identify it from the Bosch VE. Need to know what you have, and how many hours on the pump?

jamesh · Oct 21, 2018

I have a Bosch VE with 1450 hrs

Dieseltech · Oct 21, 2018

Does it make any difference how full the fuel tank is? Still sounds like air entering the supply somewhere in the system. 1450 hours is not many at all for a VE pump, but I have seen them act up just like that on early Dodge pickups when there's an air leak in the supply line to the feed pump. Rust holes are common on older trucks. Any pump will act up if there's air with the fuel, and some are worse than others. CAV DPA pumps won't handle ANY air at all in the inlet, one good size bubble and they will shut down. Bosch VE are not so sensitive to air in the system as the DPA is.

AJ. · Oct 22, 2018

Start at the tank,see the cap vent is clear there should be a filter,close the supply valve remove the line,turn it back on and check the flow if ok coming from the tank if so put it back and remove it from the feed pump and see if you have a good flow there,you are looking for a kink or blockage in the line,some of those machines had a small metal in line filter before the feed pump that needs to be clean as do the primary and secondary filters,the machine is supposed to be self bleed,have a look at the banjo bolt on the return line,I'v had that trouble on the backhoes but the tank was lower than the engine and should the feed pump in valve have a hair on the seat the fuel would ran back over night,start up in the morning go for a second,cut out and no go again till bled,then go all day,try priming the feed pump till it goes limp before starting and see what it does,there were two types of feed pump the plunger type and the diaphragm type,if you have the plunger type nip it up after bleeding.
AJ

jacks · Oct 23, 2018

Is it possible to install a piece of clear tubing on the return line? If so you can see if air bubbles are present. My 6BT Cummins had a similar problem, and it turned out to be a loose connection at the tank on the supply line to the lift pump. I am not sure if your machine has a lift or transfer pump, but if it does, air can be sucked in where ever there is a loose fitting, or defective piece of tubing or hose.

Case 850 D needs to be bled every morning

jamesh

Member

Dieseltech

Well-known Member

jamesh

Member

Dieseltech

Well-known Member

Dieseltech

Well-known Member

jamesh

Member

Dieseltech

Well-known Member

AJ.

Well-known Member

jacks

Member

Similar threads