The Stovebolt Site Forums The Parking Lot Big Bolts The Stovebolt Volunteer Fire Department Help identifying. Primer pump? -- 67 7500

Hello everyone I'm going to post this here and in the fire truck forum. My 67 7500 was a fire truck originally most things were removed except all this under the hood. Was told it resembles a priming pump. It was plumbed into the back of intake next to hydrovac line. The long gray tube over the fender well is brass along with the red filter canister. I would love to know what it all is. I hate to scrap it if someone could use it. Thanks in advance!

If you don't get a response in here, or in the SVFD forum, I'm guessing John M can help you. One of our trucks was a 1965 GMC-Darley Tanker Truck, shown here in the Gallery. He won't be here until the end of the day, tho

Hopefully, someone will arrive soon who can help.

~ Peggy
Roll Tide
(Grandson is planning on going to Alabama)

Thank you that would be great if he can get me in the right direction. I have worn out my poor phone trying to research it with no luck.

Adding those additional images will help.

I'll see if I can get Spanky in here in the meantime.

That big red thing toward the firewall looks like some kind of float device, similar to a boiler low water cutoff. If you can read the patent numbers on the side of it, try a search here. You may come up with something that will tell you it's purpose. I tried, but can't read those patent numbers very well and tried quite a few possibilities. It looks like it's tying the fire pump to the engine cooling system to me. That's a lot of plumbing.

[on edit] On second look that long grey thing on the fender is likely a heat exchanger, used to supplement engine cooling from the water pumped thru the fire pump. Many stationary engine driven fire pumps use that type of system for engine cooling instead of a radiator. and running the engine at high RPM's to run the fire pump would kind of stress a radiator only cooling system.

KLhansen you are correct it was plumbed into the coolant system and the big part on the firewall was plumbed into the vacuum port on the back of the intake. I didn't get pictures of it but there is also probably a six inch tall block the carburetor is mounted on. On the side of that was facing the pump there is a small gear that drives some kind of actuator that must have got the system started. I ran patent numbers and they did come back to the company that built the truck out but never a specific system. It was built out by American Fire apparatus co. Unfortunately they were bought out and eventually closed. I really appreciate the help its had me scratching what little hair I had on my head out lol.

That 65 is beautiful!

Here are some more pictures of the '65 tanker.

Maybe some of John's pictures will help.

Will still try to get John in here. He's got some other pump experience from his various lives.

As suggested, moving this to SVFD. Better traction there since this is pretty specific.


(John is on his way!)

Welcome to our site, Marc! Neat truck! Our 1972 9500 was more like your truck than our '65. You have the monster V-6 though. Wait 'til you run that baby down the road ... let me know when you do so I can buy stock in whatever gas brand you buy. My '65 had the "little" V-6 -- the 305 -- and it didn't exactly sip fuel ... Mine actually did better in both performance and fuel economy when I ditched the Stromberg Carb and the governor and switched to a Holley 350.

Looks like your truck was built with a front mounted pump. And some of the primer components almost like they were Barton?? I've seen some of that before...

Mike B will probably recognize most of it. Or some of the other guys.

Anyway, all of the stuff for the auxiliary cooling, and the priming stuff, can come off. You will be happier without all than non functional stuff in your way. I had a line like that running from my pump to the radiator. It started leaking and being a problem so I removed it and brazed closed the connection to the radiator. Same with the vacuum primer -- leaving it on there unnecessarily complicates the engine compartment, provides more entry into the system for failure "vectors" and it's just ... not needed anymore.

If you feel guilty about scrapping that stuff, don't. But if you need to assuage your guilt, you can check out the SPAAMFA web site and see if they have a way to list it. I listed all that stuff I removed from my truck that wasn't needed anymore and got no takers ... Maybe yours will find a home ... ?? Hopefully (but don't hold your breath).

Even on my '65, that was still in its fire tanker configuration, I didn't need all that stuff under the hood. Besides, my 1945-vintage Darley 500 GPM pump was tired, had cracked the case twice, had a worn impeller and just would take suction at all unless started with positive pressure -- basically, it would only pump water from the tank. It wouldn't take suction from the pond or anything, so why bother with all the primer gear? And it never pumped at high RPM for more than 20 minutes anyway so I didn't need the leaky water connection to the radiator ...

Your truck is no longer a fire truck so lose all that gear and don't feel bad about whatever you choose to do with it. In my experience, there isn't much demand for those parts. But who knows?

Had to add this since we are here.

One of my favorite shots. Our Stovebolt at work.

Marc, Welcome to Stovebolt

The red cast housing is the fire pump primer pump/controller. It's job is to allow truck engine vacuum to be used to purge the air out of the suction side of the main pump as well as the draft hoses. The controller has a float assembly that prevents pond water from being sucked into the engine once the pond water reaches the main pump...just like a carburetor float/needle seat valve. New fire engines use electrically driven primer pumps as diesel engines don't make vacuum, so all that stuff is obsolete now.

Like John said, you can/should remove all of that to clean up the engine bay...I'm sure there is someone in the world that would take that stuff off your hands, but it's probably not worth what it would cost to ship it.

Mike B

Can't thank y'all enough! Yeah I can't wait to get the old 401m running. We have 90% of the pump stuff off just actuator and block under carb to go. Whoever removed the old bed and other components done a sloppy job lot of hot wires were cut and left hanging so really want to take care of the loose ends before throwing power to the system. (Dont want to call a new fire truck out for my old one lol). It really makes me feel a lot better about those parts though. I am going in a somewhat rat rod direction so some of the brass components may get polished up and find new purpose. (Kind of seeing that brass tube turned into a light bar). Again can't thank yall enough. Peggy M has been a huge help and made me feel welcome.

Thank you sir! Between you and John yall have answered more than two weeks of internet searches and even harassing all my mechanic buddies at the penske shop we use. I'm probably going to save the Brass components and repurpose them somehow but just scrap the rest. I was telling John now it's just getting the last few bits off and chasing down the wires they left hanging and getting all that squared away.
Again thanks so much now I can have a clear conscience about not trashing something and get down to business.

Ok. From here, start posting where you need to be. Like electrical, engine, etc.


We even have a HIPO forum, if you got the rod route. Lots of fun people in there, too.

[ Thanks Mike B .... ]

I've got an American LaFrance pumper on a 61 GMC pug nose chassis. It's running the 401 V6 and a direct drive 5th. gear Clark transmission. Since the tank has a big hole rusted in it and most of the plumbing is missing, I've got plans to remove the fire bed and replace the driveline mounted pump with a 3 speed Brownie transmission. That will give me 15 forward speeds including overdrive in 5th. and maybe slightly better gas mileage- - - -from outrageously bad to merely horrible, probably! I'll install a commercial 5th. wheel and a goose neck trailer hitch, and pull any trailer I feel like backing up to! That project is about 10th. in line right now!
Jerry