roosa master pump help

[JoeBioDiesel]

I'm hoping someone who has injection pump overhaul experience can help me. I've got a 1959 Ford 871D Tractor with a Roosa Master DM pump. I bought it not running with a bad crank. The engine work is done and I tried starting it. No fuel. I took apart the pump and found the plungers in the rotor to be lightly stuck. I was able to get them loose with a small pick. I checked the plungers and bore for corrosion, and all looks good. The plungers move freely now and hold air pressure for several minutes. When I install the pump it bleeds quickly and squirts fuel freely at the injection lines but still won't pop the injectors (they pop test fine). I've had the pump apart 7 times and I don't see anything wrong with it.

Could the plungers leak fuel under pressure even when they hold air pressure fine?

Is there something else I'm missing?

I've heard that these old roosa masters are very intolerant of water and contamination, but I definitely don't see any damage inside.

Any help appreciated.

Joe

 

[ssanders60]

Roosa Master

This may sound too simple, but did you make sure that the

return line is not restricted? does it have a check valve

at the point where the return line leaves the pump, if so

examine it closely, any small piece of varnish or trash will

block the return line at this point and the pressure won't

allow it to "pop" the injectors. Let us know how you

fixed it, I am much interested in vintage tractors.

 

[Animal]

Check and make sure your delivery valve and spring are in good shape and not sticking.

 

[JoeBioDiesel]

Thanks for the speedy replies!

ssanders: maybe it's part of my problem, but there is definitely no return checkvalve. I've had it apart and checked it closely. It is easy to see that it is only a brass elbow. There is evidence that there was a screen on it at one point, but it had been removed. There is no reason to put a screen on the return side so this elbow was probably off something else. It supposedly ran with it like that. The fuel system was intact when I got it. I'm confident there are no other return line restrictions for 2 reasons. I am running it off a small fuel tank that I use for a small diesel engine I have, and I tried starting it with the timing window loose and leaking... just in case.



animal: where exactly is the delivery valve on this pump? It is a DBGVCC429 pump. The book I have is for a DB2 pump. They are a little different. The book shows the delivery valve in the center of the rotor. Mine is not there. The ends are not machined for it. There are a couple of allens in the distributor head. I took them out. 2 of them had pins underneath. but no valves came out. Any chance it's in the bottom of one of those bores? Is there a chance that there are no delivery valves in this pump?



Sorry to be a pest.



Joe

 

[DBoyd]

Hey Animal

Just a quick question, what do you use the F650 for?

DB

 

[Animal]

Joe,



Go here for delivery valve location/inspection/replacement.



http://home.comcast.net/~argve1/injection_pump_article.html



Go here for thoery on delivery valve:



http://www.tpub.com/content/construction/14264/css/14264_179.htm



Hope this helps. As to if, yours has one, I’m sure it does but not familiar with that unit.





DB, I use it for moving loads from the lower 48 to Alaska and around Alaska. I keep overloading the Dodge so I upgraded. The price was right so I made the change.

 

[JoeBioDiesel]

Hi Animal,

thanks for your help. i couldn't get the first link to work. I decided to take this thing back off the tractor, and apart once more. I'll see if I can't find a delivery valve, and then I'll punt, and send it to the pump shop. Wednesday looks like the day.

Joe

 

[JoeBioDiesel]

Well, after 8 attempts to fix thing crummy pump, I finally did it. I found an old diesel book that shows cutaways and principles of operation for a bunch of injection pumps. Apparently Roosa Master made a primitive type DB pump. It has no delivery valve or pressure regulator in the pump. It has only charge and discharge ports. I imagine it will smoke a little once the fuel delivery gets up there, but it works good so far at no load.

So. . what fixed it? Excessive bleeding. I was told by an old tractor guy that those old Ford pumps take forever to get the air out of them. I alternated between bleeding with the injection lines loose, and then tightening them. I overtightened the valves a little bit so it could crank over with no compression, allowing it to spin faster. I did this for 6 hours while I was working on the rest of the tractor. Eventually it started to make fuel. Runs good now, just needs a little adjusting on the governor... . and then bleeding again

Joe