The Stovebolt Site Forums The Parking Lot Big Bolts The Stovebolt Volunteer Fire Department 1938 Chevrolet Fire Truck with a Barton UA40 front mounted fire pump

I need to remove the shaft from the engine to the pump to replace the fan belt. Has anyone on here done that before? It is a straight drive shaft with no unjoints in it. It appears to have some type of slot coupler at the engine and goes directly into the pump.
Wayne Bryant
Bethel Fire and Rescue
Bethel, NC

Hopefully someone in the Stovebolt Volunteer Fire Department can help.

Hy WingWayne, Merry Christmas, there should be a spline or keyway setup on one end or the other that will allow the drive yoke to slide away from the engine once it is unbolted from the balancer or hub, hope that helps.

Wayne
MikeStem will jump in and know how it is designed, when he checks in.
Michael is the Midwest expert on Fire pumps.

Also, welcome to the Stovebolt group.
As you can see, in just an hour and a half, you are already getting replies.

I'm with 3B on some kind of spline setup and you may have to unbolt the pump to slide foreward to disingage the spline.

Get as many numbers and the brand of pump you can, to be ready for Mike's questions.
Keep us posted and post pics!

Don King

Thanks for the quick replies, yes there is a key way setup,on the drive end and I have loosened the two Allen screws on the sleeve/coupler but is does not move freely and I did not want to start pulling or prying until I heard from the experts! The correct model number on the pump is U40 and not UA40 as posted earlier. I am also in search of a operations and maintenance Manual if one is available.
Thanks,
Wayne Bryant

If it has allen screws, it is not likely original to 1938. Be careful so you do not break hard to impossible to replace parts.

I would love to see some images of this apparatus.

Are you in the Haywood County Bethel area?

Thanks Paul, I have been told that it is a 1938 but I have also heard stories of it from 35 to 38 and you are correct parts are hard if not impossible to find so I definitely will be gentle. I will try over the weekend to take pictures and post them here.
Wayne Bryant

Sorry Paul, forgot to include that I am in Pitt County

Wayne,

Too bad you are on the opposite side of the state from me, I would like to see your project.

Paul

Wayne,

Sorry I took so long to see this. I've rebuilt a few of these Bartons, and my favorite is the U-40, which is what's on my '40 Chevy. The "A" in "UA" refers to a pump that has the heating/cooling jacket around the front of the impeller, to prevent freezing in the winter. The "U"s didn't have that jacket, as it was a later development.

As for the drive shaft: The EASIEST solution is to replace the belt with a link-type belt, which bypasses the tremendous hassle of removing - or at least tilting - the pump to get the drive shaft out. When my fan belt broke the year I got my truck, I purchased a suitable width link belt from Grainger. They're awkward to size - removing and replacing the links takes tremendous finger dexterity - but it worked well. You will have to ignore the ever-present warnings in the catalogs that say "not for automotive use". I ran mine for months, until the engine went down for a rebuild. Fact is, early autos (and fire trucks!) used link style belts in the early days from the factory. As long as you get enough depth in the pulleys, without binding, it will do just what it's supposed to do. Frankly, the only danger is, if the link belt brakes, you lose your fan and generator - so the engine may overheat, which is how I figured out my belt had broken! If you are accustomed to keeping an eye on your guages, you will have an early warning that something is wrong.

OK, that's the easy answer: Here's the hard one. If you're hell-bent on getting a proper replacement belt on there, than you don't have any choice but to remove the pump. It's not actually as awful as it sounds, depending on your plumbing situation. The pump mounts to an upside-down triangle mounting plate with three big bolts, and has ears that rest on top of the mount. Disconnect the intake line from the booster tank, as well as the discharge line to the booster reel - both hopefully have unions somewhere in them, or at least a section of flex line.

If your primer is under the hood, disconnect the vacuum line going to the front top of the intake. And if your truck has an auxilliary cooler, you may have to unhook the water lines going to and from the pump to it. Not remove totally, just unhook.

Now - wrap a chain on an engine hoist around the pump or attached plumbing and snug it up before loosening the mounting bolts. Keep 2 things in mind:

1, Do NOT disturb in ANY WAY the mounting plate! This plate is what has been aligned when it was installed to keep the drive shaft in proper alignment to the engine. As long as it stays put, the pump will go right back to where it needs to be.

2, ALL you need to do is pull the pump forward enough to get the drive shaft loose, maybe 2 inches. If it's not the double-u-joint shaft like you say, it's the original - or an inservice replacement - style, which is called a 3-jaw clutch style, I think. Either end of the drive shaft has a round clutch with 3 "teeth" or jaws, which mate with the 3 teeth on the pump side, and pulley side, respectively. These jaws were designed to take up minute misalignments in the mounting, and allow for flexing, to an extent. When you look at it carefully, it's hard to feel it was a good design. The double-jointed shaft that replaced these was a far better idea.

I would do my best to mark each end of the shaft to maintain it's indexing, so it goes back right how it came out. There may be a radial spring within the jaws either or both ends - keep your eyes open, though we couldn't totally understand the point of these, and I'm not convinced they're necessary.

When you put the new belt on, you may consider putting a second belt around the shaft, and wiring it up somehow to the back of the pump or the grill or something, so you don't have to go through this whole process if the belt breaks again - a spare already in place.

I'll send you a Personal Message with my phone number so you can call me with any questions. I also have a digital manual with drawings that would probably help.

-Michael

Wayne,

Forgot to mention, for the benefit of the others, and history, the original, 3-jaw style shaft was double-pinned usually, and not designed for slipping the jaws down the shaft. Even the double u-joint shafts weren't designed for easy removal. We have toyed with the idea of adding a sliding collar arrangement to effect shaft removal, but in most cases, it's impractical.

-Michael

Great info I really appreciate the info! I had already investigated and figured that the three main bolts would need to be removed and in addition there is a small angle bracket at the bottom front of the pump that will need to be removed as well. I absolutely love the idea of the spare belt and will incorporate this in my repair. The generator is out for repair and with good luck and parts arriving on time I hope to perform this task this weekend. I would love to look at or get the digital manual for this pump. Again, thanks for the info!
Wayne Bryant