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CAV Injection Pump Parts Position?

Working · 2025-09-27 10:08

Curious if the these roller keepers are in the right position?

Replies20
  1. #1thepumpguysc2025-09-27 15:20

    No.. the one on the left is wrong.. The pump is seized and snapped off..

  2. #2Working2025-09-27 20:19

    Understood. Thanks. Does anyone know any affects this keeper being backwards would cause? Would it just run the same but less efficient? Other issues?

  3. #3thepumpguysc2025-09-27 20:41

    I doubt seriously it would run at all.. The one in the picture isn’t going to run PERIOD.. the rotor is snapped off and the other piece is seized in the head..

  4. #4Working2025-09-28 10:04

    Oh yeah. I know this rotor is toast. Just wondering others opinions on what the keeper in backwards would cause. The engine did run after the pump re-work, but had a "skip" right from the beginning and all the time while running. Finding this seems to indicate the keeper in wrong caused an imbalance in fuel deliver and/or firing making the engine skip but I doubt it would contribute anything to the rotor shaft breaking.

  5. #5thepumpguysc2025-09-28 10:26

    The keeper isn’t in wrong, it’s the “shoe” that’s in backwards. Just trying to keep ur terminology on track.. Have u figured out WHY it seized.?? I think you’ll find that it was: “Mechanical Side Thrust”..

  6. #6Working2025-09-28 12:59

    Can you elaborate on "Mechanical Side Thrust"? Thanks.

  7. #7thepumpguysc2025-09-28 13:08

    The manufacturer has come up with a seizure chart.. depending on the seizure pattern will determine its cause.. If u send me a prvt msg with your home email, I’ll forward u the chart.. But inorder to see the seizure pattern u have to press the rest of the rotor out of the head, a 20 ton hydraulic press is required... or cut it out..by splitting the head with a grinding wheel.. The different seizure patterns are: Dirt/contamination, Mechanical side thrust/ assembled wrong, Plugged injector,

  8. #8Working2025-10-02 10:07

    If anyone's interested. Broken CAV rotor shaft removed from seized pump head.

  9. #9thepumpguysc2025-10-02 11:48

    Using the seizure chart, what’s your diagnosis.?

  10. #10Working2025-10-02 12:12

    Well...I find the pictures of the chart difficult to see and compare to be honest. (Thanks for sending.) And I would need more experience on various failures of this sort to give the best answer. I do work on, repair, and diagnose cause for failure of various rotating assemblies however. So based upon the assymetrical wear on the shaft (one sidedness) I would guess an imbalance causing side torque increasing friction, heat, & expansion closing the tolerances to the unbalanced i.e. side torqued side to the point of seizure.

  11. #11thepumpguysc2025-10-02 12:51

    It DOES look like that. BUT I’m leaning towards moisture/water in the fuel.. seeing it’s between the charging and discharging ports.?? But with seeing that 1 shoe was in azz-backwards, I tend to agree with you.. “Mechanical Side Thrust”.. BUT that signature is at the bottom, at the transfer pump end..or at the top, at the plunger end..

  12. #12Working2025-10-02 13:40

    Maybe a combination. Not uncommon to find there are contributing factors or warnings that reveal themselves at failure of equipment and teardown.

  13. #13Working2025-10-04 11:05

    Old on bottom. Anyone know of why the o-ring channel discrepancy? Curious...

  14. #14thepumpguysc2025-10-04 11:17

    Just an update.. your kit will have both orings.

  15. #15Working2025-10-07 11:27

    50/50 a broken rotor will throw timing?

  16. #16thepumpguysc2025-10-07 11:42

    Once the rotor breaks/seizes, it stops pumping/working immediately..period.. If the pump was put together with that shoe/roller in bassackwards..it would have created “mechanical side thrust”..& that would have seized the pump.. If you’re STILL looking for what caused your pump to seize.. Drain your tank, clean it out. Blow out all the fuel lines coming to & going out of the pump, tank and filters.. change the fuel filters.. And have the pump done by someone who knows what they’re doing.. Good luck

  17. #17Working2025-10-07 14:15

    Oh, I understand completely a rotor break is instant no pumping. I was thinking, wrongly, out loud with the previous question about a broken rotor throwing timing off between engine and pump. But, again maybe thinking wrong, if the engine and pump were running in correct time when rotor shaft broke, and the engine was not touched/cranked between pump removal and reinstall...they should remain in time regardless. A break or damage would have to occur on the spline side to go out of time. What posed the timing question is I have fuel shooting at lower bleed on pump & fuel at all injector connections cracked at the nuts, and have bled various low pressure diesels over the years successfully, but not getting this one to run thus far.

  18. #18Working2025-10-16 19:30

    Tractor Running.

  19. #19Vetech632025-10-16 19:41

    What did the fix cost you?

  20. #20Working2025-10-16 20:20

    "This" fix cost about $10.00 for gasket & washers. Long story. But a summary is I didn't know anything about this type of pump. And I don't have a test table system so I sent it to be rebuilt. Never ran right after rebuild. After about 10 hours or so, the shaft snapped. Pump company stated evidence of water caused seizure. I disagreed but nothing was offered so I was stuck. As part of a rebuild the head and rotor are replaced. I had the original undamaged ones. So I put it all back together with what's been on it 30 years or more and she's running as good as ever. Will put it to work soon and see what else breaks. lol If one elected to buy the head, rotor, gaskets, & other parts...looking around it seems about $300.00? $350.00? This is not EVERY part but the heart of it. Disclaimer though is I'm not in the business and you have to be careful what's true parts vs. Chinesium knockoffs. What I have learned after going through this type of pump is that the majority of the time, if the equipment ran when you last parked it, but now it won't start due to no fuel at injectors, the pump doesn't need to be sent off for rebuilding. Dismantling, cleaning, & getting proper movement of even the worn parts will more than likely solve the issues. The plungers in the rotor head appeared to be the primary problem before I sent it off. Stuck due to lack of use and in my opinion, the pump will inevitably get "dirty" inside over the years no matter how diligent we think we are with filters & fuel.