'71 Roosa Master DBG cam pin split

[RuralTowner]

Roosa Master DBGFCC injection pump off a 71 CASE 580. Never been apart from what I could tell as the tamper wires were still in place OR it was a factory reman. Pump badly fouled so needs to come apart for cleaning & re-seal. Cam pin (original spline type) cracked in half during removal & even egged the stabilizing bushing. Tried coiled tin tapped in around the ball-head after using a magnet to seat it together. Just flexes & tool spins. Turned down a compression gauge adapter to clear the belly screw opening & drilled the center to fit tool in but it just split. Thought if could find "tower hose clamps" small enough to fit 1/4in hose it could be moved into place then tightened on the coil again since the screw would be accessible but smallest I've found is 3/4 & there's no room to get one that large in there.

Looking for input on other options//tips on removal while half the pin head is still attached.

Also possible source for another pump body//compatible models if the extreme option of cutting it off to use vice grips becomes the option.

 

[m16ty]

I’ve heard of people cutting apart the housing to save the pump internals when this happens. Then just buy a new housing, and likely a new cam ring.

 

[RuralTowner]

That's on the table as a last resort. Just need to know what//where to look for in compatible replacements ie cheap core donors or if they tended to all share the same main housing. This one has the round flange & rectangular viewing windows.

As of this posting am a short time away from finding out if my rudimentary machining skills...effectively summated only by what I've seen others do...using a small 50+ yr old shop lathe that's sat for years that dad used. Found some 1" round stock & turned it down to ~7/8 which fits with a SMALL amount of wiggle room into the bore to either side of the pin. Drilled a 9/32 hole for the tool then followed up with a 1/2 for the pin that goes only 3/4 the way through. The new pin barely starts & the HOPE is once split across the hole can insert the 2 jigs & hopefully sandwich the remaining pin + chip into place by clamping down with a C-clamp. This way the pin should be FULLY supported & ideally has NO room to move which gave false hope every other attempt.

 

[Al Baker(pumpman)]

I have removed hundreds if these over the years. I Have never had to cut the housing apart. Guess I haven't done enough of them, or just been lucky. Sometimes it just pays to have someone with experience do the work. GOOD pump work pays for its self. Most times a dull chisel does the trick. AL

 

[RuralTowner]

Guessing the chisel would be used on the sides to rap on the pin to ideally free up the threads a little?

Not apart but POSITIVE progress. The 2-pc jig gives full support but cut them a bit too long (poke out the sides a bit too much) & now the largest clamp I can find still won't fit. So lined it up in the big vice I was working off of with only the jig making contact. Inserted spline tool & gave light taps with a small hammer...no budge of any kind (including no sign of ball separation). Next used a short cheater & applied light pressure...no budge yet good or bad. Wish I had the means to mill a partial-globular recess in each instead of just a bore hole so could get the 2 sides to meet up flush but still give JUST enough clearance to not bind. Somewhere got a die-grinder. Pump needs better support since it fell out of the jaws. Need a better clamp that way the vice can just keep things from moving. Quit while I was ahead for now & try more tomorrow.

Most the pumps share a common main body?

I was given a recommendation for Industrial Injection of Utah (I'm in AZ) from a local guy I got all my 80s VW diesel stuff from so will follow up on that route if it comes to it. Sending it off to make it someone else's problem is somewhat tempting...would like to know what methods they use but wouldn't be surprised if a method similar to mine is used in some cases. The guy I'm helping can't afford much. The loader he recently bought that had the pump was claimed by the seller to have been recently running...but with the state of the rest of the fuel system that is panning out to be a line of bull.

 

[Dieseltech]

SOME pump housings will work for both left and right hand rotation, some LATER housings are rotation specific. Most have brass shaft pilot tubes, and some have steel tubes which MUST NOT be used in the Case 188 application.

 

[m16ty]

Do you have a pic of what the current shape of the pin is?
Did you use the correct Bristol wrench to try to remove when it split or a ground down torx bit?

 

[m16ty]

SOME pump housings will work for both left and right hand rotation, some LATER housings are rotation specific. Most have brass shaft pilot tubes, and some have steel tubes which MUST NOT be used in the Case 188 application.

Never saw one with a steel pilot tube, was that on the newer ones? Also, I’ve never seen one that you couldn’t change rotation on, but I’ve only been into older pumps.

 

[Dieseltech]

The VERY EARLY cam screws were Allen wrench type, those were then changed to Bristol. the LATEST use Torx head screw. Steel tubes are used on pumps that the drive shaft DOES NOT ride in the bushing, all IH 361/407 engines have the steel tube, and the Late vertical mounted JD 404 engines use them also.

 

[RuralTowner]

Couldn't get back to it today as had other errands. Was able to find another C-clamp. Will get images of the pin state up tomorrow after work. Pump mounts on the Left side of the motor so is CCW.

Not the first injection pump I've had apart but is only the 2nd of this type...first was on an 80s vintage Miller Wildcat w/ the Waukesha 155D...it had an almost identical pump problem (solenoid cut-off instead of manual) with internal fouling but it had the Torx pin & came out no problem//snug but minimum effort required. Hadn't even heard of the Bristol wrench or stabilizer bushing until this predicament. Damage started in the field. Recognized it wasn't Torx but none on hand fit. Used a 1/4 Allen & didn't take mush pressure to feel it give in a bad way. Was immediately after that found the RIGHT tool (Bristol) that came with a new Torx pin. But damage done...spun in the bushing by hand when it arrived then snugged it down over the pin. First attempt with wrench the pin cracked more & egged the bushing (there went $35) just enough which became a bear to get out. Pin head almost perfectly split in half on top & angles over to the sie of the shank. Fortunately the bore cap still fits & seals with an O-ring.

Ever jinx yourself when working on something? I distinctly recall saying...just prior to trying to loosen the pin the first time...was "last thing needed is for this pin to break". One of these days...though it's unlikely to be heeded (when is it ever?) to listen to that nagging voice. Little comfort knowing I'm far from the only one to use a 1/4 Allen in the Bristol which a known//accepted method but comes with risks. One new-pin source indicated that the factory liked to overtighten these in the first place.

 

[m16ty]

Those pins can be pretty tight. I've got the correct Bristol socket and I've had the best luck hitting them with the electric impact. Seems the jar of the impact breaks them free easier than trying to break free with a wrench. There is a torque spec on that pin, but I'd have to dig my book out to know it.

If all else fails you can cut the advance unit off the housing, then you can get a pipe wrench on it. A good housing shouldn't be hard to find, those DB pumps are everywhere on old engines if you get to looking. I think just about all the major manufacturers used the DB pump on several models, probably one of the most common pumps there is, second maybe to a CAV.

 

[Scott 730]

Those pins can be pretty tight. I've got the correct Bristol socket and I've had the best luck hitting them with the electric impact. Seems the jar of the impact breaks them free easier than trying to break free with a wrench.

I think I read somewhere that one recommended procedure is to tap the wrench with a hammer or hit it sharply with your hand to shock the pin loose, instead of slow steady pressure on the wrench.

 

[Dieseltech]

I think I read somewhere that one recommended procedure is to tap the wrench with a hammer or hit it sharply with your hand to shock the pin loose, instead of slow steady pressure on the wrench.

And if you hit the screw too hard then the cam ring will break, ruining it

 

[Scott 730]

And if you hit the screw too hard then the cam ring will break, ruining it

So the cam ring can break from a sharp rotational blow to the wrench? I was not saying to strike down on the head of the advance screw.

 

[Dieseltech]

So the cam ring can break from a sharp rotational blow to the wrench? I was not saying to strike down on the head of the advance screw.

Not by rotation, but some guys like to hit the screw with a punch and hammer, that can crack the cam at the screw treads. I've seen that a few times in my fifty years and counting of pump repair.

 

[RuralTowner]

Scratch 1 T45 Torx. Only one I had was a cheap DuraLast that was already a tad distorted...not impact grade but did tap firmly into place. The RYOBI impact driver (not the drill but one using the 1/4 hex stuff) tried but only succeeded in eventually stripping the rest of the Torx tip after holding the trigger for 30 seconds. Fits REALLY good now in the new pin (won't use the bit though). C-clamp was only lightly snugged enough to keep tension on the pin head...still has a gap between the sides since haven't yet made alterations to fully cup as biggest good bit I have is 1/2 when I likely need 17/32+. Tomorrow will get a proper impact-grade.

Finding a bunch of DB2 pump for cheap. Even some bare housings for next to nothing. DBG internals would swap over if the rest of the body matches?

Got images of the pin finally. Can see the jig tool (pokes out over 1 in either side beyond pump) really needs to be bored a bit more to close the gap more for better holding w/o outright pinching.

 

[RuralTowner]

<Insert hesitant towel throwing> It's great finding a bunch of tear down guides but would be good if could also find those that include pin extraction.

RIP 2 more Torx. Those pins are some HARD material. Set back up to try again using a basic heat treated Torx & used sharp impacts this time on a breaker bar. Just head flex since the jig doesn't have hemispherical recesses. Took out a little material in the jig so it could fully close & not pinch but also had to open the smaller opening a hair more so the 3rd impact-grade this time Torx could fit w/o trying to spread the halves. Even that one was stripping. Pin being split leaves just enough of a hairline crack for the bits to shift even though they inserted snug. Wish had the means to make a hemispherical retainer jig that would give absolute support so worse case ONLY the head or tool strips instead of pin splitting.

Found a local racing shop that might be able to take over. Be taking the pump in. Also completely forgot about a local equipment sales//repair shop that might be able to take it on. The latter might be able to get a slightly better charge rate as it's where work gets some parts. Most the used donor housings that might work would still cost about the price of pin removal. Now just deciding on to do that or proceed with incremental drilling.

 

[m16ty]

After looking at the pics, it’s going to be tough to get anything to hold with the pin split.

 

[Mark-Ia]

<Insert hesitant towel throwing> It's great finding a bunch of tear down guides but would be good if could also find those that include pin extraction.

RIP 2 more Torx. Those pins are some HARD material. Set back up to try again using a basic heat treated Torx & used sharp impacts this time on a breaker bar. Just head flex since the jig doesn't have hemispherical recesses. Took out a little material in the jig so it could fully close & not pinch but also had to open the smaller opening a hair more so the 3rd impact-grade this time Torx could fit w/o trying to spread the halves. Even that one was stripping. Pin being split leaves just enough of a hairline crack for the bits to shift even though they inserted snug. Wish had the means to make a hemispherical retainer jig that would give absolute support so worse case ONLY the head or tool strips instead of pin splitting.

Found a local racing shop that might be able to take over. Be taking the pump in. Also completely forgot about a local equipment sales//repair shop that might be able to take it on. The latter might be able to get a slightly better charge rate as it's where work gets some parts. Most the used donor housings that might work would still cost about the price of pin removal. Now just deciding on to do that or proceed with incremental drilling.

Send it to Diseltech, the resident injection pump guru.

 

[Scott 730]

Looks like it's time for the die grinder or Dremel and a good cutting bit. Or have a machine shop mill the head off. Worst case you would need a new cam ring. IMO. YMMV.