Top Washers

Gdubs

Member

Equipment
Bobcat MT 55
Jul 2, 2021
54
0
6
New York
Does anyone know the function of the two port holes in the top washers that go between the injectors and the overflow tube in a D902 engine?
 

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,542
1,057
113
Kansas City, KS
Does anyone know the function of the two port holes in the top washers that go between the injectors and the overflow tube in a D902 engine?
The fuel flows through the holes to get from the injector into the return tube.
 

Gdubs

Member

Equipment
Bobcat MT 55
Jul 2, 2021
54
0
6
New York
I thought so

Local kubota dealers’ tech told me regular cooper crush washers we’re fine, but it wouldn’t fire, and I can see constant air bubbles in the return line going from injector pump to overflow tube, even after bleeding the entire system.

Could these two things be related?
 

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,542
1,057
113
Kansas City, KS
I thought so

Local kubota dealers’ tech told me regular cooper crush washers we’re fine, but it wouldn’t fire, and I can see constant air bubbles in the return line going from injector pump to overflow tube, even after bleeding the entire system.

Could these two things be related?
The sealing washers have to have holes in them for the fuel to flow freely. If they did not need the holes, they would not put them in the correct washers.
 

Gdubs

Member

Equipment
Bobcat MT 55
Jul 2, 2021
54
0
6
New York
Should I assume since I’ve been trying to start it with no luck, that the wrong washers kept the overflow from entering the tube and have been dumping excess fuel into cylinder?
 

awitty

Member

Equipment
d1150 & d950
Oct 11, 2021
34
2
8
uk
Should I assume since I’ve been trying to start it with no luck, that the wrong washers kept the overflow from entering the tube and have been dumping excess fuel into cylinder?
Did you manage to sort this problem? I have a similar issue with lots of air bubbles coming from the injector pump overflow line.
 

Gdubs

Member

Equipment
Bobcat MT 55
Jul 2, 2021
54
0
6
New York
Yes it’s all sorted and the washers were one of the culprits

i got correct ones, a set of reman injectors, new overflow tube, all new fuel lines, and still ended up rebuilding the engine again because a retaining ring fell out of the wrist pin seat and scored the cylinder

as far as the bubbles go, it was a symphony of problems and solutions as far as I can tell. I wish I actually knew what main source of bubbles was though
 

awitty

Member

Equipment
d1150 & d950
Oct 11, 2021
34
2
8
uk
Yes it’s all sorted and the washers were one of the culprits

i got correct ones, a set of reman injectors, new overflow tube, all new fuel lines, and still ended up rebuilding the engine again because a retaining ring fell out of the wrist pin seat and scored the cylinder

as far as the bubbles go, it was a symphony of problems and solutions as far as I can tell. I wish I actually knew what main source of bubbles was though
Thanks for the update. I think I'll focus my attentions on the injectors as everything else checks out ok.