D7F injection pump

[Mquinista]

I own a IP related business, with a friend that owns a Diesel repair shop we provide systems out of OEM specs, Tunned Injection Systems for all aplications people search for, (not often CAT´s in our neighbourhood)
We never had a CAT IP at the shop in last 20 years,(they do not fail, very often problems can be dealt in installation) and 20 years ago i was not on the business, but this pumps are no diff from Bosch systems or Stanadyne just to name couple, Inline Pumps usually are build in 2 separate parts at least, the Pump and the Governor.
Most Inline Pumps including CAT´s need to be balanced(Injection timing between Cylinders , so they fire 120 degrees apart and not 123 as ex) that can only be done in a bench tester.
Most of them fuel calibration, as well, its possible to do it on the installation, but its advisable to take it at IP shop so it can be corrected to OEM specs.

For non diesel aquaited mechanics or hobyists, usually reports are same as u posted... no fuel out of all pipes, not firing, assembly dificulties and so on . Correction its not easy, if one has repaired critical systems as for exaple seals on the barels or plunguers , disconection of GOV from pump housing... rack seals .

Some CAT Inline pumps need to be bled plunguer by plunguer and they jerk off without the valve(injector) in the line. Foamy or bubling fuel when one crack the line is quite common, is very common. specially if the main galleries and piping was out for some reason, thats not a problem.

What i sugest before u go any further is checking all 6 valves(injectors) receive fuel, and bled them out, crack at the top of valve. Rack full fuel position, if u have doughts on GOV assembly, Push it by hand.
Crack the line just a bit for fuel to squeeze out, not completly open, foamy fuel may will come out, if needed u can remove valves from engine and check injection to atmosphere.
This is easy done in 1 hour by 2 gents. This procedure is the first we do in the bench test squedule, 1 to check for proper assembly , 2nd for unwanted leak detection.

Once u´re sure pump is injecting, only 2 problems to correct, if u have any of it, Pump Timing and Governor settings.
Besides rack movement from the governor there is no point chasing after idling or max RPM , CUT off and so on, that u can do after u fire the engine and set it at proper timming.

As i know CAT IP timming on 32/33/34/35 series engines is pretty much bullet prof, one locks the fly wheel with a special tool at the CYL 6 Fire position, lock the pump with the tool, and slide the pump in the gear, there are the fine timming but that is of no need for now.
Check the book if u have one, sometimes the place to use the tools difers , someting that does not differ is both locks must match.

And this procedures will alow u to get the engine firing, if the governor is not controlling rack properly the engine may not start due to lack of injection , thats why i mentioned to slide it by hand if needed.

Installing governors are a tricky business, some of them even have add ons that play critical roles like the Torq limit function, altitude compensation and so on.

First lets see if u can get the fuel out of injectors and fire the MF .

Hope it helps,
good luck

 

[Jchuff95]

Yes sir, I’ve cranked and primed until batteries died out twice(brand new batteries from cat), had to be recharged overnight by generator….

I’ve tried starting fluid also but after it runs out of spray in intake it only does a “pop….. pop” like it’s hitting on one cylinder each rotation.

don’t believe it could be timing other that the rectangular connection between pumps, I didn’t remove cam or gear(only pumps and rack).

Didn’t remove any fuel lines other than the short tube between transfer and injection.

I’ve done the steps I’ve done for years, work my way up the line until I find air. But the problem is we have great(non aerated) fuel with gravity or hand pumped(injectors lines loose or off) BUT ONCE YOU START CRANKING, IT GETS “VERY AREATED”

I’ve had her spun up quick on ether and I’d say have total of 3 hours cranking with same results.

 

[Mquinista]

don’t believe it could be timing other that the rectangular connection between pumps, I didn’t remove cam or gear(only pumps and rack).

Didn’t remove any fuel lines other than the short tube between transfer and injection.

Then u have a problem in the pump elements... they are not injecting anything ... the problem is in the plunguer and barrels, either they not seat in the cam, they leak(are not sealed properly) , or they are not rotating in the right amount cause they turn when the rack is actuated... they turn to increase fuel output and to decrease, and shut off , no fuel out...
somehow u manage to leave that thing in the wrong manner, try to redo that right way.
remove injector to check for injection quantity and move rack by hand to see what´s going on....

 

[Jchuff95]

Then u have a problem in the pump elements... they are not injecting anything ... the problem is in the plunguer and barrels, cause they turn when the rack is actuated... they turn to increase fuel output and to decrease, and shut off , no fuel out... somehow u manage to install that thing in the wrong manner, try to redo that.
remove injector to check for injection quantity and move rack by hand to see what´s going on....

by the manual and dial indicator I am getting the ~ 22 mm of travel which should mean I’m good on travel. The 3 pumps(plunger and barrel) I ordered online already had gear on rod but I didn’t try to check them(hopefully right from factory). The other 3 I just cleaned up with parts washer and fine cleaning pad. Cleaned up the little plunger and spring in top(cap with threads for injector line). I’m thinking possible barrel off time or possibly my oring is sucking air?

 

[Mquinista]

by the manual and dial indicator I am getting the ~ 22 mm of travel which should mean I’m good on travel. The 3 pumps(plunger and barrel) I ordered online already had gear on rod but I didn’t try to check them(hopefully right from factory). The other 3 I just cleaned up with parts washer and fine cleaning pad. Cleaned up the little plunger and spring in top(cap with threads for injector line). I’m thinking possible barrel off time or possibly my oring is sucking air?

Thats exactly what i was trying to say, when u assemble that thing u got to check fuel sincronization between cylinders, so when u push the rack all cylinders receive same amount of fuel.
That is done by checking plunguer heigh @ top of stroke, and by rotating them (Individually) to seat on the rack gear...
I´m not very familiar with those pumps as i mentioned, at a distance i´m not able to direct u exactly how to fix it, but untill an experience member can help, i got a clue on how to get there by trial and error,
First check wich injector is giving fuel, that probably is the one plunguer that is correct, then rotate the other barels in the position they inject the same amount as the one thats firing.

Eventhough once u have them all in sync, the rack might be in the wrong position. But that is secondary, cause once u got the dozer running u can also understand if its thr well, idling well and turning off well.

If it was a bosh pump i could help in close eyes , nevertheless its similar , just in bosch pump its the plunguer that turns, and the barrel is shimmed to the desired output.

 

[Jchuff95]

Thats exactly what i was trying to say, when u assemble that thing u got to check fuel sincronization between cylinders, so when u push the rack all cylinders receive same amount of fuel.
That is done by checking plunguer heigh @ top of stroke, and by rotating them (Individually) to seat on the rack gear...
I´m not very familiar with those pumps as i mentioned, at a distance i´m not able to direct u exactly how to fix it, but untill an experience member can help, i got a clue on how to get there by trial and error,
First check wich injector is giving fuel, that probably is the one plunguer that is correct, then rotate the other barels in the position they inject the same amount as the one thats firing.

Eventhough once u have them all in sync, the rack might be in the wrong position. But that is secondary, cause once u got the dozer running u can also understand if its thr well, idling well and turning off well.

If it was a bosh pump i could help in close eyes , nevertheless its similar , just in bosch pump its the plunguer that turns, and the barrel is shimmed to the desired output.

Thats exactly what i was trying to say, when u assemble that thing u got to check fuel sincronization between cylinders, so when u push the rack all cylinders receive same amount of fuel.
That is done by checking plunguer heigh @ top of stroke, and by rotating them (Individually) to seat on the rack gear...
I´m not very familiar with those pumps as i mentioned, at a distance i´m not able to direct u exactly how to fix it, but untill an experience member can help, i got a clue on how to get there by trial and error,
First check wich injector is giving fuel, that probably is the one plunguer that is correct, then rotate the other barels in the position they inject the same amount as the one thats firing.

Eventhough once u have them all in sync, the rack might be in the wrong position. But that is secondary, cause once u got the dozer running u can also understand if its thr well, idling well and turning off well.

If it was a bosh pump i could help in close eyes , nevertheless its similar , just in bosch pump its the plunguer that turns, and the barrel is shimmed to the desired output.

That’s my problem, I’m getting fuel and it’s about even across all 6(without a measuring cup). It’s like it’s got an air suction leak only when cranking, it’s got me stump. I read a few other forums before asking any questions…. Hand pump while cranking, cracked lines at injection pump and after I got fuel there then I did the line at the injector. What is also making it a pain is the ~20° slope(blade down hill) dozer ran for 3 hours pushing dirt, the. I went to push huge oak tree down the hill to valley….. boom it died with rack stuck. I did the wrong thing by tapping rack back and forth cracking the “rod” above the gears. So I dissembled only upper part of pump(didn’t want to mess up timing on gear) cause I can’t fine timing set fixture for the pump.

With with fuel on at tank the injectors ports on pump(all 6 will run fuel out) when cracked. I can pump and immediately get the best air free fuel ever, but it once you crank it all bets are off, it will spray a stream 8 foot away from the dozer from injection pump but once air is gone and hooked up you get one lonesome cylinder trying(pop). But when it isn’t spraying 8 foot while cranking it’s almost like foam. 50% air 50% fuel.

I even tried pressuring the tank with 5 psi with no luck. I kept all the shims with the pumps they were for. I would think it would atleast try to pop off on more than one since 3 are old.

In the book it says to center rack which I made a tool out of rod, old gear off broke pump and bushing to hold rack centered when installing plungers, and check everytime I dropped one in, it say I think ~22 mm if it’s okay and if you get one tooth off it’s like ~16mm (not by book rn)but I had 22 all the way until the end.

The connection between transfer and injection can only go 12 o’clock position or 180° from that(like a flat head screw and screwdriver) i put it back based on the unique ware spot on it. Only worry is that the connection has a different ratio from
The crank or cam to pump(like I need to time first injection port to first cylinder) but I don’t have the special tops from cat to check perfectly

I appreciate everyone’s help that is trying to help me I really do.

 

[OzDozer]

Have you checked the entire length of your fuel lines for corrosion pin holes? I have had steel fuel lines corrode where they're clamped, or where they sit against the chassis and where dirt and moisture has built up.
You get pinholes in the lines in these positions and they will leak very small amounts, but the transfer pump will draw air in from them.

 

[D6 Merv]

U might have 1 stuffed injection capsule thats blowing compression back into the system. Remove injection pipes where they screw onto nozzles. Crank engine over, see if any shoot out air.

 

[Jchuff95]

Have you checked the entire length of your fuel lines for corrosion pin holes? I have had steel fuel lines corrode where they're clamped, or where they sit against the chassis and where dirt and moisture has built up.
You get pinholes in the lines in these positions and they will leak very small amounts, but the transfer pump will draw air in from them.

I wouldn’t believe so unless I possibly did it reinstalling, I was lucky to not touch fuel line from tank to transfer pump. But there like a 3 inch double ended bung between transfer and injection put I removed but replaced oring when I did. My only guess right now it to maybe plug off injection pump and pressurize the tank plus lines for an hour. Just hard getting a compressor to it rn

U might have 1 stuffed injection capsule thats blowing compression back into the system. Remove injection pipes where they screw onto nozzles. Crank engine over, see if any shoot out air.

im was kinda thinking this, it would explain the air on crank only I believe…. They shoot air between streams of fuel when cranking. Could you pressurize(couple psi) the individual pumps to see which one is stuck?

 

[Mquinista]

Well, u seem to have a pretty nasty thing going on there…
1- i still did not understold why u went messing with the pump
2- did u remove the pump from the engine?
3- have u checked the 6 injectors opened to the air as I mentioned?


we have seen in the shop so badly damaged injectors that compression goes up the line and flood pump with air, mimic a air leak in the main gallery and consequently not injecting properly. (highly unlike)

we also seen debris accumulating in the injectors and clogging completely the system.

as far as I know even with a bad lift pump this system would operate without problem as long as it has fuel fed by gravity, no need to pressurize thank, I also assume u checked the filters, cause I seen many troubles which filters and lines were the culprit…

 

[Jchuff95]

Well, u seem to have a pretty nasty thing going on there…
1- i still did not understold why u went messing with the pump
2- did u remove the pump from the engine?
3- have u checked the 6 injectors opened to the air as I mentioned?


we have seen in the shop so badly damaged injectors that compression goes up the line and flood pump with air, mimic a air leak in the main gallery and consequently not injecting properly. (highly unlike)

we also seen debris accumulating in the injectors and clogging completely the system.

as far as I know even with a bad lift pump this system would operate without problem as long as it has fuel fed by gravity, no need to pressurize thank, I also assume u checked the filters, cause I seen many troubles which filters and lines were the culprit…

#1) cause we called injection places and they didn’t want it, or had field service techs say no cause the hill or just not come back. And it can’t be a field ornament for years so if nobody else is gonna do it I will. It’s a neighbor farmer that I’m the property manger of, they had this dozer since 90s(only a few hours a year put on it)

#2) I removed the injection pump from the transfer pump like I’ve stated a couple times. Took it home to my shop where I have a lot more tools and cleaner environment.

#3) I’m guessing I’m not following your drift (I’m getting fuel from all 6 about equal)

I have done everything by the D333c books EXCEPT check the small gear position on the 3 new ones I installed. The old ones should atleast do something. But I’m think it should atleast be able to start or pop off on old 3 pumps.

The rack what centered and I made a tool to hold center. It says in manual to go full range with rack ~22 mm if you mess up one tooth it will be about ~16mm.

I think the only possible solution is when the guy stated it maybe back pressure from other cylinder when it’s not delivering fuel.(I’m guessing it’s the small piston in top of each injector or in in the injectors)

I’m getting air from somewhere. Tank is 1/2 full, the original culprit was water in tank after sweating over the year I believe(rusted 3 rear pumps solid) but the front 3 were fine. I keep the shims with the corresponding barrels(other than new ones).

I Pressurize tank and I have no external leaks, the fuel is 99.9% air free ONLY WHEN GRAVITY OR HAND PRIMER.

I’ve maintained every tractor, even rebuilt case powershifts, replace/rebuilt engines and do everything else for these people(in their 80s) I’m not fresh to this and also been working on Mack trucks for 10 years.

not here to make money I’m just trying to get this thing moved atleast to a barn 300 feet away before snow but only working on it in free time.

It foams/bubbles only when cranking and the air is between the firing order if that makes since (when #1fires you get a steady stream but the others foam, when #2 fires same thing, every line but #2 will foam while #2 shoots a 8 foot stream)

 

[Jchuff95]

And

Well, u seem to have a pretty nasty thing going on there…
1- i still did not understold why u went messing with the pump
2- did u remove the pump from the engine?
3- have u checked the 6 injectors opened to the air as I mentioned?


we have seen in the shop so badly damaged injectors that compression goes up the line and flood pump with air, mimic a air leak in the main gallery and consequently not injecting properly. (highly unlike)

we also seen debris accumulating in the injectors and clogging completely the system.

as far as I know even with a bad lift pump this system would operate without problem as long as it has fuel fed by gravity, no need to pressurize thank, I also assume u checked the filters, cause I seen many troubles which filters and lines were the culprit…

And sorry I forgot to mention we changed filter and drained water when I first used it, pushed dirt a couple hours, changed filter on it after once it shut down but didn’t know it was mechanical issue.

 

[Nige]

#3) I’m guessing I’m not following your drift

Let me attempt to shed light on the suggestion above.......

What @Mquinista & @D6 Merv are suggesting is a test procedure for the fuel injectors to ensure that the check valve inside each one is closing correctly and that compression (air in other words) from one or more cylinders is not finding its way back to the injector pump via an injector line (or lines).

It's a simple check:
1. Disconnect all 6 lines to the injectors at the injector end. Move them completely out of the way so that the screwed fitting at the end of each injector is completely exposed. To do this you may have to loosen clamps and/or the lines at the injection pump end.
2. With the governor control in the OFF position have someone hold a rag over the open end of one injector. Crank the engine over on the starter for a few seconds and observe whether fuel/air is being blown backwards out of the injector. Repeat this test for each injector in turn.
3. If more than 1 or 2 injectors have leaky check valves I would personally suggest to replace all 6.

 

[Jchuff95]

Let me attempt to shed light on the suggestion above.......

What @Mquinista & @D6 Merv are suggesting is a test procedure for the fuel injectors to ensure that the check valve inside each one is closing correctly and that compression (air in other words) from one or more cylinders is not finding its way back to the injector pump via an injector line (or lines).

It's a simple check:
1. Disconnect all 6 lines to the injectors at the injector end. Move them completely out of the way so that the screwed fitting at the end of each injector is completely exposed. To do this you may have to loosen clamps and/or the lines at the injection pump end.
2. With the governor control in the OFF position have someone hold a rag over the open end of one injector. Crank the engine over on the starter for a few seconds and observe whether fuel/air is being blown backwards out of the injector. Repeat this test for each injector in turn.
3. If more than 1 or 2 injectors have leaky check valves I would personally suggest to replace all 6.

Thank you, great write up! I wasn’t sure the injector itself was check valve like that. I will try this as soon as I’m free(probably 4 days from now)

Anything to add I’ll be glad to try from anybody else to before I go over there.

I will try to video the “foam” I keep calling it, if nothing fixes it.

 

[Mquinista]

Hey, got back… haven’t had much time this days…
ok that D7 has a 333 engine and I was thinking it was 3306 …
333 is PC engine right? If so besides the injector may clog the PC may clog too. Both things are highly uncommon but happen every now and then… they do cause of contamination.

my question was why did the engine stop in first place… not why u removed the pump, cause that I figured out. Fuel pump problems besides leaks and contamination are very rare. And again that thing is clockworks either u know what to do or is better not to touch it. but since u did let’s thy to help u out if we can.

What u report does not make much sense… plunguers can not have air leaks… air trapped in fuel gallery may give u trouble my guess is u already bled it. Nevertheless if u have compression return from a bad injector that yes may give u those problems. Again having that is uncommon.

what Nige suggested it’s true to check delivery valve on injector. That valve should arrest anything comming back down the line. And the line stays pressurized , to be ready for next stroke. I also suggest u to remove the injectors and test them, test in open air.
I also suggest u to check the PC for clogging , if your engine is a PC type engine. u just crank it with the injectors out , and all 6 cylinders must wissle out.

but if I was in your shoes I would remove IP, injectors and lines and diesel shop i’d go.

 

[Dave Neubert]

If you are getting aeriated fuel only wile cranking it has to be your injection nozzles just had this problem with a 955 the customer put after market nozzles in and 2 of them were blowing back on compression stroke. remove the fuel lines at the injectors and see if any are blowing back

 

[Jchuff95]

Hey, got back… haven’t had much time this days…
ok that D7 has a 333 engine and I was thinking it was 3306 …
333 is PC engine right? If so besides the injector may clog the PC may clog too. Both things are highly uncommon but happen every now and then… they do cause of contamination.

my question was why did the engine stop in first place… not why u removed the pump, cause that I figured out. Fuel pump problems besides leaks and contamination are very rare. And again that thing is clockworks either u know what to do or is better not to touch it. but since u did let’s thy to help u out if we can.

What u report does not make much sense… plunguers can not have air leaks… air trapped in fuel gallery may give u trouble my guess is u already bled it. Nevertheless if u have compression return from a bad injector that yes may give u those problems. Again having that is uncommon.

what Nige suggested it’s true to check delivery valve on injector. That valve should arrest anything comming back down the line. And the line stays pressurized , to be ready for next stroke. I also suggest u to remove the injectors and test them, test in open air.
I also suggest u to check the PC for clogging , if your engine is a PC type engine. u just crank it with the injectors out , and all 6 cylinders must wissle out.

but if I was in your shoes I would remove IP, injectors and lines and diesel shop i’d go.

I’ll just type a replay, I’m sorry I didn’t understand what you meant by why did you take pump off.

Early morning august 22nd I drained water and changed filters, brung our transfer tank down and filled 50%

had a main water line installed nearby and the company gave dirt to the farmers to fill sink holes(~20 tri axles) I pushed up dirt into a pile for I’d say 2-3 hours.

then preceded to drive across the farm I’d say a half mile (Using a lower valley to traverse) I then came to where the tree was just laying there(BAD spot in the middle of the slope) county road at top of hill.

So I went up the hill about 10’ from road and did a 180° turn( blade down hill) I had headphones on so I pressed blade against the tree but felt a power loss, to remove my headphones and it was dead.

Only the weight of the dozer on the hill was keeping it rolling, dropped blade and set brake.
(Now it sets halfway from valley to road(about 300 feet from road)

Changed filters first, then what I didn’t know( I do now) that the dozer has to have fuel lock for oil pressure in governor after noticing the pedal was stuck, I preceded to just remove the governor housing cover to find the rack was stuck but not the rack itself(could feel I’m guessing gear lash)

I tried the tapping rack method back and forth with very small hammer with no luck

vvvvvv So now here we are vvvvvv

3 new pumps, with all new bonnets and bonnets seals for all 6

New oring between transfer and IP

I believe we have changed filters 3 times now. Destroyed a battery cranking so we replaced both.

The main thing is that it must have been water I believe, cause I still couldn’t get 3 rods to move or come out of pump after I got them removed from housing.

I have a video of her purring on August 22nd at 7am and did good with dirt for hours.

 

[Mquinista]

Hey man,
Get everithing out related to injection system take it to the shop inspect everithing for rust including piping, check the pre cups , take injector to diesel shop to clean and pop test, wile u there overhaul pump and have it bench tested and adjusted.
I'm so sorry but i don't think u will be able to get it cleaned and set correctly by youself.
Rust contaminated all the system and is the injectors making the assle

 

[Jchuff95]

Hey man,
Get everithing out related to injection system take it to the shop inspect everithing for rust including piping, check the pre cups , take injector to diesel shop to clean and pop test, wile u there overhaul pump and have it bench tested and adjusted.
I'm so sorry but i don't think u will be able to get it cleaned and set correctly by youself.
Rust contaminated all the system and is the injectors making the assle

What I was thinking now, one field tech did say that I should fill tank 100% in off season to try to combat sweat water. It always indoors other than now for obvious reasons lol.

I’m sure this is the case with any pump, put he said “water was the enemy of these things”, I guess I possibly just got a domino effect going now when the water got to pump.

What is the best way to prevent this again, i thought maybe putting some oil in filter housing and let it take some into pump then shut it down until we need again(possibly months)

I was reading lastnight after the replies and in the book I found where the nozzles are replaceable item known to wear.

But anyways I will do the couple test and possibly get pic or vid if not luck, or track down someone to go over pump and injectors.

 

[Mquinista]

Thing is, once a IP is rusted inside due to water everithing the water touched is pitted, sometimes one can salvage some parts, but usually is overhaul time with huge budget as parts are expensive. Very often a second hand part is the go, being aware that it may be in the same condition.

Water in thanks usually are due to condensation of humidity of the air inside tank, the less air the less humidity accumulates.
thanks usually have a water sump for this reason.
but if tank is 40 year old without service it can accumulate a lot of rust and water… filters and water separators should prevent that.
No need to have drastic preventive measures like u mentioned for a machine that works every season, just check if water sump is working and top it. Before u use it next season clean sump, until good diesel come out drain water separator , give it a new fuel filter and u are good to go.
as long as pump is filled with clean diesel everithing is fine for years.

Now that we got the picture of what happened, we can conclude u had a bad contamination by water some time ago it caused many parts after the filter to rust, and this rust released and clogged everything upstream the plungers. The fact that u replaced some parts did not solved the problem.

Solution I guess is to clean everything, nozzles , lines, pump, check if PC are clean, and try to start it, and u may be lucky to be able to bring the horse to stable. Once there I guess u know what to do.

Pls post your next results so we learn from your exp.
regards