Stovebolt.com 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. [ppubs.uspto.gov] 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 [s160.photobucket.com] 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 [spaamfaa.org] 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?