Exhaust Mod on my 3725

[Logan65]

Slowpoke Slim - I know this is an old thread, but frankly it is the one that got me to join the tractorbynet entity. I have a 2019 Branson 3015...DPF light went on, about 75 hours after my father in law told me I didn't need to run the engine so fast. I am planning on copying your efforts, and I just want to know...a year and a half after you modified your exhaust...would you do it again if you had to? Still a good decision? Thanks!!

 

[Slowpoke Slim]

Logan,

I apologize for not responding sooner, I know work has slowed or stopped for many lately, but I'm "fortunate" enough to be deemed "essential" (I work on life safety equip in commercial and municipal sites), and this is normally our busy time of year, and I'm frequently working out of town.

On to answering your question:

Short answer, "Yes". I would do it again, and I still think it was the best option "for me".

I think the biggest reason mine has been so trouble free since the mod is I used a very good quality exhaust shop to do the work. The guys fabbing and welding skills were excellent, and the finished product still looks like it could have been shipped from the factory that way. I have no broken or cracked welds, and no exhaust leaks anywhere.

I have zero issues with starting or running my tractor. No power issues, idle is still smooth. The tractor has not gotten any louder in exhaust note or tone since the initial start up. I can start and idle my tractor as long as I want, run it only hard enough for whatever my power demands of the job are, and no negative side effects to the tractor or engine.

I still get the same puff of smoke when I first start the tractor when cold that I did the first time I started it after the mod. Once the engine runs for a few seconds (always less than 10) the smoke puff is gone, and the tractor exhaust has no smoke or soot in it. Even working it hard, I don't get smoke from the tail pipe, and certainly isn't "rolling coal" or any such indications of excessive exhaust.

The exhaust does smell like normal diesel tractor exhaust now, and no longer smells like new born puppy farts. But it runs no different than any properly tuned "pre-Tier" tractor would. I do not run my tractor in any enclosed spaces, so I personally could care less about the "diesel smell" of the exhaust. If I was running it in a working greenhouse with people around, maybe I'd feel differently about it. But I don't run a commercial nursery or similar where I would have customers nearby to complain about "smells".

I still think the main reason I had so much problem with my factory system is the ambient temps here in winter cause the filter to operate at temps that never get to the level required for it to function properly. There was just no way that DOC filter was going to go from -40F to a +1000-1200F without starting to pack up with soot. It would just take too long to get that hot without some kind of external heat source (like a fuel injected igniter to burn in a regen).

So yes, I'm happy with the mod, and wouldn't hesitate to do it all over again. Perhaps I wouldn't have waited as long as I did if I'd have known how great it was going to turn out. Now I can decide based on the work I'm doing, at what rpm and for how long I want to run my engine. And I don't have to run the dog-snot out of my engine when it's not required to do so. I have noticed a significant fuel savings and it's just a more "user friendly" experience to operate now. It's easier to talk over the sound of an idling engine, than to try to yell over the howling of a max-revved engine, for an example.

 

[Logan65]

I think the biggest reason mine has been so trouble free since the mod is I used a very good quality exhaust shop to do the work. The guys fabbing and welding skills were excellent, and the finished product still looks like it could have been shipped from the factory that way. I have no broken or cracked welds, and no exhaust leaks anywhere..

Slim,
I appreciate the feedback, and the 'essential work' you have been doing; I am still active duty military, and deemed essential, so the last 2 months have been entertaining...

Regarding the weld quality...my shop is good enough, and is looking for business these days. I am more concerned about all the 'stuff' that seems to be plumbed into the factory DPF cannister right now...by unplugging and corking things, would I be affecting a vacuum signal or some electrical sensor that adjusts 'something' in the engine? What did you do with yours?

Are my late-80s Chevy MPFI nightmares/flashbacks misplaced?

I am deep in the heart of TX, where it gets hot, hotter, and less hot on an annual cycle; we will never see the subzero stuff I remember from growing up in PA and upstate NY. Many times I am merely putt-ing around box blading and pulling trees, but the bushhog, rototiller, and posthole digger are all broken out frequently enough to force the occasional high RPM usage.

Lastly, for now - I think I had read one of your responses in an earlier thread that your DPF light is now always on, and you are ignoring it? I have been researching many sources of info, and may have your data confused with another.

Many regards, and thanks!
Logan

 

[ptsg]

There is a box in front of the radiator. That looks like an ECU but it's just the Datalogger for the DOC. Once you unplug that, the light goes away.

If you need any pictures of the exhaust setup on a 15 series, let me know. I have a F36Rn, which is basically a European version of the 3515 but narrower and with different features. Comes from factory without any emissions crap on it as it's wasn't required here. From 2020 and on, it will be requires on new tractors though.

 

[Slowpoke Slim]

Slim,
I appreciate the feedback, and the 'essential work' you have been doing; I am still active duty military, and deemed essential, so the last 2 months have been entertaining...

Regarding the weld quality...my shop is good enough, and is looking for business these days. I am more concerned about all the 'stuff' that seems to be plumbed into the factory DPF cannister right now...by unplugging and corking things, would I be affecting a vacuum signal or some electrical sensor that adjusts 'something' in the engine? What did you do with yours?

Are my late-80s Chevy MPFI nightmares/flashbacks misplaced?

I am deep in the heart of TX, where it gets hot, hotter, and less hot on an annual cycle; we will never see the subzero stuff I remember from growing up in PA and upstate NY. Many times I am merely putt-ing around box blading and pulling trees, but the bushhog, rototiller, and posthole digger are all broken out frequently enough to force the occasional high RPM usage.

Lastly, for now - I think I had read one of your responses in an earlier thread that your DPF light is now always on, and you are ignoring it? I have been researching many sources of info, and may have your data confused with another.

Many regards, and thanks!
Logan

We U.S. market Branson owners are very fortunate that at least for now, Branson is using an add-on emissions system that is a separate package they install on tractors sold in U.S. market only. What they've done is taken their "normal" tractor design, that they sell basically all over the world, and "added" this DOC system to it. This allows them to sell the same tractor models all over the world, but by checking an option box at the assembly line, this emissions system is added during the build...

I'm paraphrasing for emphasis, I don't really know that this is exactly what they do...

But functionally, and mechanically, what this means for us Branson owners here is, that emissions system is wholly stand alone, and doesn't tie into the engine controls in any way. They put the filter on in place where a muffler would go (in any other country they ship to), and they add a "data logger" to the top of the battery bracket. Then there are sensor wires that go from the data logger to the filter cannister, and a lead wire goes to the idiot light on the dash (and of course, power from tractor power to turn on the logger).

The only purpose the data logger serves, is to light the dash light if the exhaust gas pressure gets too far out of whack between the input side of the filter, and the exit side of the filter. That's all it does. It is an entirely "passive" system.

So as far as the actual engine operation goes, the engine has no idea whether or not a filter is in place, or a data logger is in place. They stand on their own as a separate system. Now if the filter gets plugged, (partially, or wholly) then the only impact on the engine is that it's trying to run through a plugged exhaust pipe (like a plugged muffler for example).

There is no other computer of any kind on the tractor.

What this means is that "YES", you can take the filter off, put a muffler in that filter's location (it is the same location that a muffler is installed in for the rest of Branson's world market), and the engine will run fine. The only reason you "need" to unplug the data logger, is so that the idiot light doesn't light up on the dash.

I have unplugged my data logger, and removed it from the tractor. Since doing that, my dash light never comes on.

Data Logger, at least on the 25 series (mine), it is located on the battery hold down bracket:



This retaining clip must be released, small screw driver in previous pic works well to press in tab, then rotate clip to right (in pic):



Then pull connector straight out the side of the logger. It was in there very solid, with a tight seal.



I was originally going to take the entire harness out, but it is woven into the main tractor harness, and I just didn't want to take the entire thing off, separate it out, and put the rest back. So I wrapped up the plug in plastic and tied it back to it's harness. The sensor wires are also tied back to the harness at the other end.

It's been this way for over a year now, and I haven't had any issues of any kind.

 

[Logan65]

You, Sir, are truly 'the man' and I am grateful. Now, if I could just make the time to get the hood off, get a muffler in my hands, and get the whole package to the weld shop, life will be grand. I appreciate all the input, imagery and description!!

 

[Slowpoke Slim]

Just don't do what we did and forget to unplug the headlights before you lift the hood off. We got the connector apart, but it was much more awkward to do while the 2 of us were trying to hold on to the hood. And the hood comes off easier with 2 people.

 

[nrosario]

Interesting, this is my first time seeing this post.
This might help sell more Branson tractors.

 

[Branson Bob]

I'm returning to this subject because even though the dummy light has not gone on, I believe my DPF/DOC is getting clogged. Starting is harder, idling is rougher, throttling up is erratic, and power is less. This came on the heels of running my backhoe for a fairly long period of time and also after my neighbor, who is a heavy equipment operator borrowed the tractor to do some grading. He definitely ran it at a slower engine speed due to being accustomed to running commercial equipment that run at lower RPMs. Between these two factors and the cooling weather, I believe my filter is clogged.

I do want to eventually swap out the filter for a muffler but where our land is located there are no exhaust shops close by and I don't do that level of welding and fabrication.

On this topic previously there are those who've "gutted" the filter and I'm wondering if any of those people can chime in here and relay their experiences so I have more info as I prepare to gut mine. Also is it possible that my problem lies elsewhere (air:fuel mixture)?

Thanks!

 

[ericm979]

Could be a partial blockage in the fuel system. The light should come on if the DPF is clogged. People here have reported the light coming on before there's a noticable performance impact.

You can try working it hard (i.e. on the road in high range) to get the DPF hot and burn off some of the soot.

You can also get the DPF cleaned for a few hundred $$. Lots of places do it.