"New" B-275

[CathedralCub]

Hello all, thanks for letting me in! Looks like a great forum with lots of knowledge . . . as well as respect for the members!

Since this is my first post here, a little about me: I got into the world of tractors and antique engines in the mid `90s, joined an EDGE&TA branch, did parades and fair demos and work parties, then life got busy and I ended up drifting away. Now it's a few decades later, the family and I have moved states twice, and I find I have some time, incentive, and opportunity to get back into it. Somewhere along the way I got an F-30 that is restorable but so far has only been yard art, and soon will be picking up an H that I have a little history with. As time allows, I intend to contribute here as time and knowledge grow to allow it. I'm the admin at one major automotive forum and moderator at another.

I just got a 1960 B-275 diesel. Runs pretty well but looks rough. I'll be using it around the property, and as we bond a little and trust grows, I might take it to shows and parades etc. . . . casual stuff. Somewhere along the way it's getting fixed up quite a bit. Probably not a full frame-off etc. but I definitely want it to look younger and maybe leak a little less!

I'm sure I'll have many questions going forward, but so far I only have one: What is this little tube that my pen is pointing at?:

It produces a continuous drip of diesel whenever the engine is running. Previous owner says it has always done that.

If it is normal for some reason, I'll plan on figuring a way to filter it and return it to the tank. If not, I'd love to fix it!

Thanks for any help!

--CathedralCub

 

[CathedralCub]

benjaminoah sent me a PM with this:

That tube is part of the leak-off / return from the injection system. Fuel is supposed to come out of there, but it should be plumbed back into the return line to the tank, not dripping on the ground.

On those B-275s there is usually a small steel line or hose from that fitting up to a common return manifold that also takes the injector leak-off back to the tank. If the return is missing or plugged, someone may have just left it open. Do NOT cap it solid; you need that bleed path or you can mess with pump/injector operation. Run a new small line back into the existing return line. A wider shot of the area would confirm.

When I sorted fuel leaks on a friends B-275 I used the service manual from https://machinecatalogic.com/case-b275-international-harvester-service-manual-ih-201/ for the return line routing.

so . . .

 

[CathedralCub]

. . . so . . . I replaced all of the rubber lines in green and added the line and tee in red:

. . . and then started it up. It ran fine for about two minutes, then suddenly started gushing diesel out from under the thing circled in blue and started running rough.

I shut it off and the gushing slowly subsided.

So now I'm thinking that maybe I've added a path for the return fuel to siphon down from the injectors through the tee . . . ?

I can't find another path back into the tank for fuel return. I'm betting I don't need to add one, as there must have already been some solution for this.

Maybe a check ball inline in the red path?

What do y'all think?

Thanks!

 

[CathedralCub]

Some more pictures:

 

[JimB2]

Have you changed the fuel filter lately?

 

[CathedralCub]

No, that's on my list. Would that cause this?

 

[JimB2]

Could be causing excess back pressure on the input side of the feed pump or the valves inside the feed pump are not opening and closing properly. See photo below of similar feed pump but there is a sediment bowl on the bottom right of feed pump.
See top left of page on the feed pump action driven by the cam in the injection pump, and how it pumps the fuel.
Usually the lift pump just leaks around the hand pump lever. Neighbor had a B-250 with that style of CAV injection pump.
Never was into feed pump, only changed fuel filter for him. Drove the B-250 frequently.
Hope this helps.

 

[nashranch]

your injection pump is an inline pump. that control on side of it must be a primer. I would probably bypass it with the fuel lines to eliminate the leaking. This is a different pump than the one i had. I am putting up some of my setup. Mine smoked uncrontrollable so i removed pump and sent it to Dieseltech for a rebuild. Worked good after that

 

[JimB2]

His B-275 has the older CAV inline pump like the B-250 and the part that is leaking is the feed pump and the hand primer. Usually they leaked around the hand primer but his appears to be leaking around the inlet. Later B-275's had the rotary CAV pumps.

One thing I forgot to mention was to make sure the hand primer was turned down tight, it has been 60+ years since I changed the fuel filter on a B-250 but I remember having to turn the hand primer lever one direction to release it and then you could pump the plunger to prime and then you had to push the handle down and turn it to lock it in the run position.

 

[Dieseltech]

That tube is the CAMBOX OVERFLOW DRIP TUBE. It SHOULD BE LEFT OPEN, and NOT plumbed back to the fuel tank. Ford/Simms pumps had the same tube.

 

[CathedralCub]

Thanks JimB2 and nashranch ! I'm learning a lot!

 

[nashranch]

YOUR WELCOME... glad to help

 

[CathedralCub]

That tube is the CAMBOX OVERFLOW DRIP TUBE. It SHOULD BE LEFT OPEN, and NOT plumbed back to the fuel tank. Ford/Simms pumps had the same tube.

Thanks for the reply Dieseltech!

So is it just supposed to drip on the ground? Like when it was brand new in Bradford, UK, being driven onto a truck to be shipped to the new world, was it dripping from this tube?

Is there any reason not to direct this back to the fuel tank? . . . even through a separate dedicated return line?

I'm guessing maybe that would be too far above the tube and it isn't able to push fuel up that high? If so, I might just rig something up that collects the fuel and then pumps it up to the fuel tank every once in a while.
. . . OR . . . is it something that is feasible to repair?

 

[CathedralCub]

Okay, I added a temporary "catch can" made out of a 5qt empty oil jug with a hose leading from the drip tube into the lid (which has a nearly-perfect-size hole cut in it). It hangs from the clutch pedal arm between the shaft and the tab for the return spring. While I was cobbling this together, I had it running and collecting into a 1qt oil bottle. It collected at a rate of 10 minutes per ounce. Based on this, the big jug gives me over 26 hours of runtime until the jug is full at idle. That should do for now.

In the meantime, if there is a way to fix it, I'm very interested. If this drip is normal or inevitable even after fixing, I'll look into a more-"professional" tank with a float switch of some sort connected to a small pump to occasionally pump it back into the fuel tank.