Stanadyne Roosa Master Pump Rebuild Help

McGatha185

New User
Hello there. Here's what's going on. My Allis Chalmers 185 has sat idle for the last two years while I've worked through college. When I tried to get it going again, I found that my priming pump was bad and had let all the fuel leak out, so the entire thing was dry. I fooled and played with it for a couple weeks and did every trick anyone would tell me to try and get it started, but I'm to the point now that I'm doing my first rebuild of a Stanadyne Roosa Master diesel fuel injection pump. Here's it's numbers: DBGFC-637-34FW; 1339760; and 4022395. I'm sure that sometime in the past a different D2800 engine was put into this tractor. Under the peeling Allis orange is yellow from their heavy equipment lines. This pump also has the electric shut-off instead of the manual, which I've been told was never available on the 185 tractor.

Anyways, I've gotten my Stanadyne rebuild kit, I've got the pump off the tractor, I soaked and cleaned the outside, and now I'm slowly...carefully... disassembling this dog. My daughter is taking pictures and filming with her fancy camera setup too, just in case I need to reference back. I'm trying to play it safe. Ok, I've disassembled the whole thing except that the hydraulic body will not slide out of the housing. The rebuild manual just says: "Grasp the hydraulic head assembly firmly in both hands and withdraw with a slight rotary motion." It ain't sliding though. Won't budge the tiniest bit, like it's one solid piece, which of course it's not. I'm afraid to get mean with this for fear of breaking something. Do you have any suggestions? I could touch it briefly with a torch to flex the metal. I'm kinda leery of this with the diesel it may still have in it. I could dunk it in water first though. Would tossing it in the freezer for a while then into a warm oven help. The hydraulic pump and the housing are two different metals so they should change sizes at different rates. Right now I'm going to shoot it down with PB Blaster and see if that helps. Please give me any advice you have for getting this apart and any problems I might encounter getting this back together. Also I know that putting this back on the tractor can be a problem with those umbrella seals on the drive shaft wanting to turn inside out. Any advice on that?? Thanks!!
 
Do you have the advance bolt out of the cam ring??? It takes a Bristol spine wrench to get it out. Also some guys grind down a torque but and it will work but if the pump is still factory I have seen the torque bit shatter the advance bolt.
 
You're talking about the odd shaped rounded bolt on the underside of the pump (inside the automatic advance "tube") with the crazy star wrench pattern, right? It's out. I can't see anything still holding this piece. I've given up on the JB Blaster and am now running hot water over the aluminum case and dipping the steel core in ice water to try to free it up.
 
YAY!! The repeated hot water on the case and ice bath for the steel core just worked. It was hard to get out still but it came out. Whew! Okay, any of you smart guys have any suggestions for me as I finish disassembling this, reassembling this, and putting it back on the tractor? I would love to hear your advice!

Thanks!
 
Any advise..?? stop now.. If you had a hard time just getting the head out of the housing, your in for a world of serious frustration..
You mentioned you ALREADY HAVE A MANUAL.. it even has pictures.
 
I get really tired of snide-mouthed injector pump guys whose every word is, "Don't do it. Only I can do it! Send it to me with a small fortune." I'm so sorry, the head was sealed into the housing, probably from old diesel that'd turned to shellac. I make programs, processes, and machine parts for F22's, the G10 missile system, patriot missiles etc etc etc. Don't worry your poor redneck head over it. I'll figure out a three pound, forty year old injector pump, just like so many others on this site and other sites have. So far, it's been child's play, but I prefer to play it safe and ask those guys who know for certain. They're usually very helpful and friendly. Unfortunately, in your case, I ran into a beer-swilling pump troll whose only reason for being on this site is to drum up business. If you're not willing to help a situation, then just shut up. You certainly don't have to act like a total jerk..."it even has pictures." Really? Woohoo! Big deal, you idiot! The pictures are not for exactly the same pump. The pictures are mostly dark spots with no definition. And where does a picture help with a core that's glued into the body? You stupid, jerk. This is my first post on this site, and you have to be the one I run into. I'll delete my account if you're an example of the characters on here.
 
I didn"t mean to come off like that.. sorry..
I was just trying to save you some heartache/frustration..
No need for name calling.. Good luck w/ your project.
If you have some SPECIFIC questions, we"ll be glad to help.
 
I have never heard anyone respond to a post like you did. Uncalled for. I do not do anything with injection pumps but I know a fair amount about them. You act like this is a mag or something. The reason you don't try to rebuild a pump yourself didn't have anything to do with intelligence its about equipment. You will probably clean it out and it will probably work but it will not be right unless you have a test bench to properly calibrate anything. As I said it will probably work and do what you want it to do. In this forum we all play nice.
 
If your going to act like a child and call people names then it may be better for us if you did delete your account. I seen nothing wrong with the responses you got. I work in research at one of the largest diesel makers in the world but I still come here for help on 50 year old tractors. There's a lot of people willing to help that will save you a fortune.
Back to fuel pumps. yes you can do it and make it work. I have replace the washer that fails on the 4020 pump several times with no problem, and I have seen a plunger installed wrong on a ford diesel and it run away destroying the motor.
 
You are new to this forum, 4 posts. You will likely get far less useful help after makeing coments like that, when someone of experience offers a sugestion. You might be a rocket scientist, BUT. enough said.
Loren
 
That aluminum housing can get pretty stuck to the steel head & rotor assembly. I usually stick the assembled pump in a bench vise, upside down with the drive-end facing up. The bottom end of the pump (cap to the rotary transfer-pump) fits well enough in the jaws of a vice. Get it in there firm and then you can get a good grip on the aluminum housing and work is back and forth in rotary motion and pull upwards as you do it. I never had one yet that did not come off that way.
 
Most everyone on these forums is helpful and easygoing. I learn a lot just by reading the posts. Lots of injection pump knowledge gets passed along. There was no reason to reply like you did.

Garry
 
Wow, I feel bad I didnt get a chance to see this post until today, (5) Jan. Always nice to see a young fella trying to repair his old tractor. So did JR. the rocket mechanic ever get his three pound child's play running? I Did my first Roosa pump in 1981 and have been in the guts of hundreds and hundreds of them sense, but never was cleaver enough to do the freezer oven thing. Sounds like a heck of a nice fella. Hope everything turned out well. Al
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top