Fuel leaking past 2 of three injectors on b7100

JerryC999

Member

Equipment
B7100HST
Aug 16, 2014
89
0
6
Simpsonville, KY
I have a b7100, new to me, and in two of three injectors, fuel seems to bubble up where they thread to the head (see pics below). Tried first time to mow and ran out of fuel after 2 hours (thinking it leaks more than it burns). Bleed the injector lines and started right back up. Looks like that middle injector has been cranked on pretty hard. Are they cross threaded? Worse?

Also, with very, very dull mower blades on the 60" belly mower, and kinda tall grass to mow, I had to mow in low gear to keep moving. Very slow, a couple miles an hour at best, going up any incline.

So, lots to do - sharpen blades, replace fluids, etc. But what about those bubbling injectors? Rebuild? Replace? Something other??





 

Grumpy560

Member

Equipment
1979 B7100D 4WD with B219 loader/ 3 G6200 HST mowers/ JD 310D 4X4 backhoe
Oct 18, 2014
178
0
16
Estill Springs TN,
Sharpen or replace blades on the deck and make sure you hit every grease zirt fitting you can find since this B7100 is new to you I'd do all fluids like you said.

Sounds like you have some worn copper crush washers on the injectors. Remove all injectors and replace the washer seals. I just bought them myself @ $1.39ea. from the dealer.

I just bought B7100 myself and have a RCK60 B24 that I will run behind the tractor once I get the engine rebuilt.
 

JerryC999

Member

Equipment
B7100HST
Aug 16, 2014
89
0
6
Simpsonville, KY
Ok, an update on the injectors. Got two of three to stop leaking, but the forward injector still leaks both at its base and at where the fuel line connects. I have removed it, polished the ends of the fuel lines, replaced the copper washer, and cranked moderately, but not super, hard on it when putting it back.

Question: How hard can you crank on these? Is there a trick to setting them solid that I am missing?

Or - should I replace it? It seems to run smoothly, but starts a little hard. Do I ignore a little fuel and bubbles on one injector, or really go after it and either use more torque or replace?
 

GEP

Member
Jun 16, 2010
103
3
18
Benton Harbor, Mi
Ok, an update on the injectors. Got two of three to stop leaking, but the forward injector still leaks both at its base and at where the fuel line connects. I have removed it, polished the ends of the fuel lines, replaced the copper washer, and cranked moderately, but not super, hard on it when putting it back.

Question: How hard can you crank on these? Is there a trick to setting them solid that I am missing?

Or - should I replace it? It seems to run smoothly, but starts a little hard. Do I ignore a little fuel and bubbles on one injector, or really go after it and either use more torque or replace?
This article may help you
The low sulfur diesel fuel got to my Kubota injector pump o-rings.
I had a continuous dripping of fuel from my pump. Mike McGragh posted
a replacement of one o-ring last year but was a little short on details.

Since more of the Kubota's are sure to start leaking, I decided to detail
my repair.
I went to the Kubota store to buy the o-rings and was told by the parts guy
that the injector pumps are not repairable. The pump must be replaced or
taken to a repair station for repair. I told the guy that one of our guys
had successfully replaced the o-rings and I just wanted to buy the o-rings.
He said they can not buy the rings from Kubota. He suggested I go to a pump
repair station to buy the o-rings. I went to NAPA and bought the only three
they had of that size. On the way to another NAPA I passed AutoZone and stopped.
AutoZone also had the o-rings.

You need two wrenches- 17mm and 19mm and a short piece of electrical tape.

1. Loosen the injector lines on the top and bottom. Just a few turns.

2. Remove the three line clamps.

3. Take the line loose from the Holder (#8 in Diagram). You may need both
wrenches to separate the line from the holder. Move line out of way.

4. Remove the holders. Because the holders are close together, I took the
outside holders first and the center holders second. Keep the parts identified.

5. Be careful not to drop the spring and washer if it comes out with the holder.

6. Remove the old o-ring. Put the tape around the threads to protect the new
o-ring when pushing it on the holder.

7. Two of the copper washers(#4 in Diagram) stayed in the holder and two remained
under the spring. I put them all back in the holder for installation. A drop of fuel
kept them inside the holder. Careful do not drop the washer into the pump.

8. The spring fits on the valve. The valve fits into an indent when centered.
Make sure they are centered before you install the holder with the new o-ring.

9. Reinstall all in reverse order. Do not tighten the lines on top at
the injectors.

10.Crank the engine until fuel comes out of lines on top. I cranked three
times for about a minute each before I got fuel out of all lines. Then
tighten the lines on top and start normally with preheat.
Attached Thumbnails

__________________
 

GEP

Member
Jun 16, 2010
103
3
18
Benton Harbor, Mi
This article may help you
The low sulfur diesel fuel got to my Kubota injector pump o-rings.
I had a continuous dripping of fuel from my pump. Mike McGragh posted
a replacement of one o-ring last year but was a little short on details.

Since more of the Kubota's are sure to start leaking, I decided to detail
my repair.
I went to the Kubota store to buy the o-rings and was told by the parts guy
that the injector pumps are not repairable. The pump must be replaced or
taken to a repair station for repair. I told the guy that one of our guys
had successfully replaced the o-rings and I just wanted to buy the o-rings.
He said they can not buy the rings from Kubota. He suggested I go to a pump
repair station to buy the o-rings. I went to NAPA and bought the only three
they had of that size. On the way to another NAPA I passed AutoZone and stopped.
AutoZone also had the o-rings.

You need two wrenches- 17mm and 19mm and a short piece of electrical tape.

1. Loosen the injector lines on the top and bottom. Just a few turns.

2. Remove the three line clamps.

3. Take the line loose from the Holder (#8 in Diagram). You may need both
wrenches to separate the line from the holder. Move line out of way.

4. Remove the holders. Because the holders are close together, I took the
outside holders first and the center holders second. Keep the parts identified.

5. Be careful not to drop the spring and washer if it comes out with the holder.

6. Remove the old o-ring. Put the tape around the threads to protect the new
o-ring when pushing it on the holder.

7. Two of the copper washers(#4 in Diagram) stayed in the holder and two remained
under the spring. I put them all back in the holder for installation. A drop of fuel
kept them inside the holder. Careful do not drop the washer into the pump.

8. The spring fits on the valve. The valve fits into an indent when centered.
Make sure they are centered before you install the holder with the new o-ring.

9. Reinstall all in reverse order. Do not tighten the lines on top at
the injectors.

10.Crank the engine until fuel comes out of lines on top. I cranked three
times for about a minute each before I got fuel out of all lines. Then
tighten the lines on top and start normally with preheat.
Attached Thumbnails

__________________
Sorry the pictures did not transfer
 

BackYardWrench

New member

Equipment
B1700
Jul 17, 2015
25
1
0
Wisconsin Dells, WI
JerryC999

here are the tightening torques for the injector nozzles and fuel line nuts.

The source is the Kubota WSM Diesel Engines 70mm Series. The right most column is ft-lbs.

Wouldn't hurt to replace the fuel return lines and the clips that go there.

Good luck.

John
 

Attachments

Last edited:

arijus

New member

Equipment
Kubota B1750
Nov 9, 2014
10
0
0
Klaipeda, Lithuania
Sharpen or replace blades on the deck and make sure you hit every grease zirt fitting you can find since this B7100 is new to you I'd do all fluids like you said.

Sounds like you have some worn copper crush washers on the injectors. Remove all injectors and replace the washer seals. I just bought them myself @ $1.39ea. from the dealer.

I just bought B7100 myself and have a RCK60 B24 that I will run behind the tractor once I get the engine rebuilt.
Question regarding running mower deck behind tractor - any particular reason for that?