pump staging valve

[mickles]

im new to the forums so i hope this is the place to ask this. i am a proud owner of a 51 GMC/LUVERNE with a 500 gpm two stage luverne senior mid ship fire pump with vacuum prime. i purchased this truck in may and have won pumping competitions with it during the summer. it is still all original(6 volt) and everything functions except the staging valve which is frozen in pressure. i am purchasing a two inlet deck gun and need to be able to pump capacity for full effect of the gun stream.

i have requested information from crimson twice and gotten no replies, so i thought i would see what i could find here on the forums.

does any body know how the shaft that extends down into the pump attach to the (i guess) the pump shaft to slide what ever it slides to change from pressure to capacity or is it flapper valves between the stages? i have taken the yoke off where the reach rod from the pump panel attaches to the shaft that extends down into the pump housing and it looks like a 3-4" plug that sits down inside. i really dont want to tear the pump apart to repair this if i dont have to.

the reason it is frozen is the previous owner(fire company) broke the grease fitting off that is in the center of the shaft that goes down into the pump and it has seized fast over time.

any suggestions or ideas?

[firetruckfixer]

I think you have what is similar to a waterous pump. I would suggest trying to get penetrating oil or stp around the shaft. Stp oil treatment works wonders with stuck stuff. I believe that pump has a barrel type valve that has holes in it to allow water through or not to. If you have a twin inlet monitor that is 2 1/2 each i dont think the 500 will be much water for it. you might be better off capping one side and flowing just one line into it. can you get pictures of the transfer valve shaft etc? if so email me at firetruckfixer2003@yahoo.com. jeff

[mickles]

i got it freed and remove as soon as i get the pictures ill send them to you for future reference.