Is it hard to rebuild Stanadyne/Roosa master injection pump

I seen rebuild kits for about 30 buck but just wondering if it is something that I would or should take on.

its your decision as we dont know what you can and cant do. its usually a job for a diesel injection shop with qualified personal. dont forget the pump needs to be set up on a test bench after o/h.

I doubt that you have all the special equipment needed to rebuild a injection pump

most injector pumps need to be rebuilt in a tank filled with diecel fuel, and as said it's not a job for a novice...just my .02cents worth...Jim in N M

Nothing special about it except that repair info is not always easy to find. No more complicated then some carburetors. Ever have to fix a GM Quadrajet??

No special equipment is needed as long as you have the tractor on-site. Test stands for these pumps are only needed when all you have it the pump, and no engine or tractor to run it on.

Stanadyne injection pump is basically just a high-pressure piston pump coupled to a low pressure rotary vane pump, with some controls added. That along with a distributor that sends the fuel charge to one cylinder at a time.

On a few applications (depending on tractor make) one special wrench is needed that cost around $8.
Other then that, no special tools or measuring devices needed. Just about all Deere and Allis Chalmer's spec pumps need the wrench. Also some Oliver, Case and Ford aps.

Keep in mind that these pumps rarely get "rebuilt." I think that word is mis-used. The pumps get resealed, patched up, calibration checked, and most major parts used over again - as is. They are NOT renewed in anyway.

I suspect that most negative comments you're going to hear about working on these pumps are from people that have never done it.

The "kit" you mention costs around $12. All that provides is all the rubber parts, i.e. o-rings, seals, and governor dampening ring. It allows you to reseal the pump and renew the governor ring. That's all. If you find any other parts worn, they have to be ordered one by one. I.e., there is no such thing as a true "rebuild kit."

Again, the word "rebuild" is misused. When you rebuild an engine, all major moving parts are renewed in some way. Not so with a fuel injection pump. Most so-called "rebuilds" get less then $40 in new parts stuck in.

A typical Stanadne/Roosamaster DB or JDB pump can be repaired while sitting on the tailgate of your pickup truck, out in the woods, if you're careful. I've done many with nothing more then some clean rags, diesel fuel, and compressed air.

No special measuring tools needed either. All fits of parts are checked by appearance and feel - not with any measuring devices.

Main max fuel setting, if you feel needs to be checked, it done with a common 2" micrometer. Timing advance can be adjusted with the pump on a running engine - with a timing light, or a $6 plastic timing window.

John is a special person that has had a lot of varied experience. He and I have always had a difference of opinion about who should attempt to rebuild/patch up a Roosa Master pump. Guess that is the perfectionist coming out of me. I have always been one that has to do it exactly right, but that is just who I am. If you are looking for perfection or have a pump that needs more than just a reseal, it needs to go to someone who has had years of experience after having factory training like John and I have had. And even then, it can be a challenge. Only the most experienced can tell by looking if a part should or should not be replaced for for a long service life. Even simple things like the transfer pump blade springs or delivery valves can be ready to fail or knowing how to check for the presence of water having gone through the pump.

I remember a CB pump that came through the diesel room that gave me fits back in the 70s. It simply would not settle down on the tractor, nor would it on the test stand. The first thing I checked was the air seperator for blockage. To make a long story short, there was a shiny sliver of steel in the bleed hole that made it appear the hole was empty. Only found it when I tried to to run a pin punch through it.

Not saying you can't do it, for I,too, have torn apart pumps on the tailage of a pickup truck,even in corn fields. The most memorable was a brand new 4320 at the Indiana State Fair. The dealer I worked for wanted to use it as a pull back tractor on the tractor pull strip and to also pull it as a demonstration. First 4320 I had ever seen as it had just been released from Deere that day, I pulled it apart, removed the shims and set the pump wide open. Talk about a new model making a show,it did.lol.
Good luck and go for it. You won't learn Any younger. bob

I always take mine to a shop. I spent thirty years on the road on backup power systems. They had to work when needed and no room for mistakes. I am sure some people can do it. But I couldn't take the chance.

We also had many issues with the CDC and early CBC pumps also. I guess that's why they had so many updates - until they were discontinued.

That all being said, there are many still around, with very high hours, still working fine. It's too bad somebody hasn't picked up the slack and made some repair parts for them.

About being a perfectionist- there's nothing wrong with that. But, sending a pump to a certified pump shop does not guarantee such perfection. Any job is only as good as the person doing the work.

Most pump shops do do NOT upgrade the plastic weight-dampener rings in DB and JDB pumps unless specifically asked to do so. That if far from what I'd call "perfection." On cars and trucks, they have to - I guess because someone "dead on the road" is apt to complain more.

I don't claim that anybody can fix one. Nor would I claim anybody can repair a starter motor, wire a tractor, rebuild an engine, etc. Some cannot even change a spark plug without getting into trouble. Somebody who is a skilled mechanic should not fear working on an injection pump any more then many other mechanical component. There is NO magic involved. Main difference is - the service/repair informations is kept a bit more "secret" then for other things.

If you've got a pump that can be fixed with less then $40 in parts, then investing $10 in tools, and $50 in a tech manual - is a worthwhile investment - as compared to sending to a shop that will sometimes charge $700 for the exact same work on a flat-rate basis. Some people who like working on equipment also like learning new things - which also has a value.

I put a pump on an old felles 806 IH one time that he'd taken to a kid that went to diesel school. It wouldn't even try to start, took it to central diesel and it was so far out of adj it wasn't even funny.

That's what I like about this board.
Enough of a knowledge base here to clear the smoke and expose the mirrors on stuff like this.
I've never opened a pump but I would gamble $30 and what little horse sense i have after reading this.
I doubt I would screw it up so it cost more than the standard $700 +- to rebuild.
And hey, It might even run.
Thanks

I'm going to agree with JD on this one there is nothing overly complex about these pumps, nothing that really warrants paying some shop gobs of money to do. I just "rebuilt"/"resealed" one this weekend and it was really pretty basic. Just pay attention to the details and you'll be fine.

Yes I would gamble too.
I look forward to learning a lot more from this board.
Thank you all for taking the time to respond and share.

In all due respect , JDemaris , unless he knows what every part does and why , in other words , unless he knows the theory behind the workings of the pump , he will not be able to do anything but replace parts. Unfortunately that is not going to get the job done . Also if it needs pump vanes or maybe new gov weights (they do wear so they don't advance correctly) you are not going to get all this in a rebuild kit for the price that has been quoted on here. The whole head could be bad then what? Think he has the training to see that? Sometimes the only way to know whether certain parts ar out too far is to assemble it and test stand it. If certain specs cannot be met or met without throwing off other specs then you need to replace some parts that you couldn't detect visually. I rebuilt these at a stanadyne authorized center for quite a while and there is only one guy in our state that can get them close without test stand and he has 40 yrs experience and learned how by the test stand FIRST until it was second nature and knew by what the engine told him. This poster might better take it and get it done right. About all the amateur is going to be able to do is dissassemble , clean and replace crumbled weight retainer ring. He won't know what else to even look for.

I work for a place that made injection pump test stands. We have three 12 cyl PSB12BT AMBAC pumps that we used to certify stands we sold to the military. We sent one out for a rebuild. Cost $14,000 and when it came back, the flow deviation between cylinders was horrible. If you are just wanting to reseal the pump, do it yourself.

That is mostly a load of BS.

First, as I've mentioned many times, the proper repair information is needed. That's going to be true with just about any type of repair for any component. If you already know it, fine. If not, read a manual.

In response to some of your comments:

You stated "unless he knows the theory behind the workings of the pump" . . .

A proper Stanadyne tech-manual will thoroughly explain all that. Does it verbally and also has many photos and illustrations. You can buy it for $50 and also often find it for free on the Net in a PDF file.

You also stated "you are not going to get all this in a rebuild kit for the price that has been quoted on here " . . .

Well, how many times have I stated that there is NO such thing as a "rebuild kit" and the kit mentioned is only a seal kit. Aren't you being a bit redundant here? Or maybe did not actually read what I wrote ??

In your penultimate comment - "there is only one guy in our state that can get them close without test stand . . "

So, I guess you know every person in your state, along with a full awareness of their personal mechanical skills? That is beyond ridiculous.
Is there some esoteric law in your state that requires anybody that works on a pump to file a official report on the outcome - so all residents are aware? Or, maybe can some guy down the road from you fix his pump successfully, and you'll never even know about it?? Tell me all about how you know what everyone in your state has done.

And your last comment - "About all the amateur is going to be able to do is dissassemble{sic} , clean and replace crumbled weight retainer ring. He won't know what else to even look for. "

If a person actually reads the tech manual, he/she certainly WILL know a lot more then that. In fact, since I've already mentioned eliminating that pellathane ring entirely, anybody that's read these posts already knows more.

You seem to have the typical arrogance that many in pump shops have. That is, "nobody in the world" can do the job, since it's so terribly complex. Give me a break! Different people have different skill levels, and that is in all walks of life. I like to think that many who bother to read these forums have a bit more interest and skill then the average person.

Go for it! If it doesn't work you're not out much. If it does you saved a bundle and learned something in the process. I do gas station service work. I have to go out of my way to make simple jobs appear difficult and complicated. If people knew how easy a lot of stuff was I'd be in the welfare line. I paid a guy $900.00 bucks for rebuild a pump and injectors. He tried twice. Took it somewhere else and paid them to fix it right for a fraction of the cost. Just cause you're paying a lot of money to get something done doesn't mean anything.

I have a john deere 3010 diesel with a turbo. I have had the injector pump off of tractor for a few years and now, after finally rebuilding engine found that the injector pump is sized up. The model number is 286784, its a Roosa Master pump. The other number on pump is JBGVC429. Some of the other numbers are XXXXX out and in one spot it has M&W Turbo stamped over the numbers. It also has RR 1.986 on it. Where can I get a manual and parts for pump. After reading your posts about rebuilding pumps I believe I can do it. I have rebuilt auto. transmissions in the past. Any suggestions, thanks, Pete [email protected]

I think this post applies to me aswell.I think I have the same pump on my 4010 John Deere.Sounds like I can do the work.But also would like to know where to get manual and parts.You guys are great thanks for taking the time to share your knowledge.

I have been reading JDemaris's posts for over ten years. You can take what he says to the bank. If you give me your email I can send you the manual.

Here's my e-mail [email protected]. Please send manual. From what I have been reading about JD, he knows what hes talking about. I wish he lived near New Jersey.. thank you, Pete

Showcrop, I was wondering if you sent me the manual for pump. I was just checking to make sure I didn't erase it. Thanks, Pete

(quoted from post at 08:30:31 02/10/14) Showcrop, I was wondering if you sent me the manual for pump. I was just checking to make sure I didn't erase it. Thanks, Pete

Click to expand...

I just sent it. I was away for a few days, not even my telephone.

(quoted from post at 06:12:42 09/06/10)
I like to think that many who bother to read these forums have a bit more interest and skill then the average person.

Click to expand...

Well, I have been looking into rebuilding this roosa pump even though I've never known anything about one till now. I'm looking at purchasing this Allis and was told that's what's wrong with it. I think I might can get a good deal on it and if I can fix it myself, it will be well worth it.
I searched google to learn about what and how they are, watched a old video about the basics of how they work, read on this post as well as others and see that jdemaris is on a lot of tractor forums and seems to be quite knowledgeable about this topic.
I have rebuilt many a carb from the small chain saw size to the dreaded Quadrajet, rebuilt transmission and engines and, frankly, with just what I have learned so far tonight, am not afraid to dive into this rebuild job. Why? Because 1) I think jdmaris is right in that the person searching on this forum for info. has the common sense to realize his or her knowledge levels in if they should take on such a build or not, and 2) The biggest thing that I learned from my military and votech training is that there is a book out there that will tell a person everything they need to know about anything if they will just take the time to look and read.
So, with that, I'm going to further my education and find that rebuild book.
Thanks for all the info. that has been put out there.

(quoted from post at 20:09:36 01/11/20)

(quoted from post at 06:12:42 09/06/10)
I like to think that many who bother to read these forums have a bit more interest and skill then the average person.

Click to expand...

Well, I have been looking into rebuilding this roosa pump even though I've never known anything about one till now. I'm looking at purchasing this Allis and was told that's what's wrong with it. I think I might can get a good deal on it and if I can fix it myself, it will be well worth it.
I searched google to learn about what and how they are, watched a old video about the basics of how they work, read on this post as well as others and see that jdemaris is on a lot of tractor forums and seems to be quite knowledgeable about this topic.
I have rebuilt many a carb from the small chain saw size to the dreaded Quadrajet, rebuilt transmission and engines and, frankly, with just what I have learned so far tonight, am not afraid to dive into this rebuild job. Why? Because 1) I think jdmaris is right in that the person searching on this forum for info. has the common sense to realize his or her knowledge levels in if they should take on such a build or not, and 2) The biggest thing that I learned from my military and votech training is that there is a book out there that will tell a person everything they need to know about anything if they will just take the time to look and read.
So, with that, I'm going to further my education and find that rebuild book.
Thanks for all the info. that has been put out there.

Click to expand...

Welcome Growyoung! There is a lot of knowledge here, but just understand that YT has two coexisting views here. The half that are on modern view will see your post, but it is not visible to those on classic view. To have viewers from classic you need to start a new thread.