No oil pressure on newly rebuilt CJ engine

Discussion in 'How To' started by Herman Ze Bus, Aug 28, 2020.

  1. Hi all, been a while since I last posted on here I’ve been enjoying my bus as much as possible...

    Until the oil light came on 30 miles away from home after a very successful 2 week road trip. Straight away pulled over and checked the oil level which was fine. I didn’t risk driving it any further and got recovered home.

    The engine sounds fine no unusual or horrible noises

    So far I’ve checked oil pressure with gauge (0)
    Replaced oil pressure switch
    Removed switch and visually checked any oil splurging out whilst cranking over nothing at all.
    I’ve checked the pressure relief valve underneath all seems ok moving freely
    Removed oil filter to check anything blocked or in housing etc. Seems ok.

    The people who rebuilt the engine are going to look at it for me as it’s all under warranty. I’ve been in touch with them all the way. But without voiding warranty now not much I can take apart.
    They just have a long waiting list to book my vehicle in, which is why I have come here to see if anybody has heard of this before?

    To add I have carried out a running in period and I’ve replaced the oil and filter adjusted and valve clearances twice since rebuild
    “a bit anal but just peace of mind”
    the new engine has covered just under 2,000 miles.

    Any advice or experience would great to hear.

    Sent from my iPhone using Tapatalk
  2. What about removing the oil pressure switch and popping a hose in to see if you get oil coming out of said hose?

    You have you got an oil pressure gauge fitted, I have heard they can get air locked & need bleeding.

    Oil pump failed perhaps?
  3. I have removed switch and gauge and cranked over still no oil or and pressure coming from hole.

    I fear the oil pump has failed. But I am not sure how serious or if any damage may have been caused internally.

    Sent from my iPhone using Tapatalk
  4. Don’t do anything with it then, wait for the builder to look, if you suspect it too.

    I don’t know how bulletproof those oil pumps are, is it a stock / correct type 4 pump do you know?
    PanZer likes this.
  5. Not much more you can do without some disassembly but if your prepared to remove the oil pump cover you can check that it is still engaged with the cam.
    3901mick and MorkC68 like this.
  6. Oil pumps rarely fail but if the engine builder is not familiar with Type 4 engines there are several things that should be checked that they may have missed. Really need full details of what has been replaced during the rebuild to comment further.

    The low oil pressure warning light only comes on when there is virtually no pressure but if you stopped the engine immediately the light came on and the engine wasn’t knocking you may have got away with it.
  7. I can’t remember the name of the manufacturer but it is a new re conditioned pump. The builder has said they are usually very strong and not had any problems before. So I can only go on there say so at the moment.

    Sent from my iPhone using Tapatalk
    MorkC68 likes this.
  8. I think they are a reputable garage who seem to been quite popular on here. So I’d like to think they know what they’re doing with type 4s

    Fingers crossed then I’ve done the right thing and shut it off when I did.

    Still, I am very grateful the fault occurred at the end of my 700 mile road trip.

    If it was the pump I’d like to guarantee there wasn’t a problem again.
    Updated Cb performance pump? Thoughts?

    Sent from my iPhone using Tapatalk
  9. Fair comment! Let’s hope it’s a simple and easy resolve and your running in no time.
  10. If it’s a standard engine there is no need to consider an alternative pump. An experienced Type 4 engine builder will know that CB/Schadec pumps are invariably a loose fit in the crankcase and leak internally. And also, may need to be machined to clear the cam gear bolts – depending on which cam has been fitted.
  11. Thank you for your comments [mention]77 Westy [/mention] [mention]MorkC68 [/mention] I just want to drop the engine and inspect further myself but I’m testing my patience here which I need to learn to do more often.

    Will keep you updated when I know more.

    Sent from my iPhone using Tapatalk
    MorkC68 and PanZer like this.
  12. Nope. You'll just have to be patient until they can take a look
  13. But is it a new or reconditioned pump? You can’t buy new original type 4 oil pumps, if it’s new it’s probably a Schadek or Melling. Schadek are aluminium, Melling are iron. Take a pic of the pump cover and we can probably tell you what it is, or at least what it isn’t.
    PanZer likes this.
  14. It’s a reconditioned pump, it looks like an aluminium cover. So perhaps Schadek I think might ring a bell.

    Sent from my iPhone using Tapatalk
  15. Flat cover or like this?
    Oil pump cover.JPG
  16. Yes that looks like it

    Sent from my iPhone using Tapatalk
  17. That’s an original 24mm pump. There usually very good but the gear can become loose on the drive shaft and stop rotating. I’d be very temped to pull the pump and check it, you can bolt it back and nobody will know – we won’t tell.:D
  18. Ohh right tempting... as long as you’re not undercover ;)
    I’m itching to do it I’m a capable mechanic however very new to the aircooled scene.
    Would I be able to remove fan shroud/housing and pulley to access it or would it be a case of dropping the engine?

    Sent from my iPhone using Tapatalk
    Merlin Cat and PanZer like this.
  19. Sorry, I don’t know, I’ve always had the engine out to remove the pump.
    @zedders will know.
    Herman Ze Bus likes this.
  20. I don't but I'd guess there is lots of stuff in the way. I wouldn't be so keen to try pulling it, I did once and snspped an ear off.
    77 Westy and Herman Ze Bus like this.

Share This Page