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Thread: IH 685 water pump failing?

  1. #1
    davids
    Guest

    IH 685 water pump failing?

    This is a bit of a follow on from my earlier post re the water temp sender. i have now noticed that when the temp gauge is reading high only the top of the radiator is getting hot. lower down the core is only slightly warm and the bottom hose remains cold.
    Ive changed the thermostat and flushed the radiator and engine block and it all flows fine and the fan belt tension is OK
    does any one know if the impeller is likely to have corroded / come adrift have you come across this before?. Ive had a quote for a new pump which isnt expensive but would like to know if this is likely before i take it all apart

    Cheers

  2. #2
    agrimax
    Guest

    Re: IH 685 water pump failing?

    Handiest way to know is to run it with the thermostat removed.You should see the water moving in the radiator.If not,it's time the pump was off.

  3. #3
    ih685xl
    Guest

    Re: IH 685 water pump failing?

    Had a similar problem with a 785L, did everything possible, new rad,water pump, took the thermostat out , just could not stop it getting hot. Ended up sending it to Cambridge sales, but did wonder afterwards if the water galley ways were blocked.

  4. #4
    davids
    Guest

    Re: IH 685 water pump failing?

    Thanks that doesnt fill me with hope!! however as the engine never seems to get particularly hot and ive had water from the hose flowing through both the block and the rad im thinking maybe the pump impeller may be at fault. I seem to remember seeing a pump repair kit where the impeller was fixed onto the shaft with a central screw. just thought that it might have come adrift. I`m going away for a few days and will investigate further when i get back...
    if any one has any more ideas please let me know

    cheers

  5. #5
    keithed52
    Guest

    Re: IH 685 water pump failing?

    Just had a DB 1290 with exactly the same symptons even with the thermostat removed checked rad flow and water pump also insde of top and btm hoses fitted new thermostat and temp sender and tested temp with thermometer from my cooling system test kit temp read about 85deg c spot on but guage still ran high ! Faulty Temp Guage easy fix hope yours is the same my customer was pleased

  6. #6
    davids
    Guest

    Re: IH 685 water pump failing?

    Thanks - Thats a good idea when i get back I will try feeding the thermocouple from my multimeter in through the top hose clip and see how hot the top end really is. maybe i`m panicking about nothing!! in fact the top hose never seems to get overly hot to the touch and the radiator cap is never under pressure when removed even when the engine has been running for some time so a double check on the temperature might be a good idea

  7. #7
    Gapples
    Guest

    Re: IH 685 water pump failing?

    I've never seen an impeller come off one of those water pumps, normally its just the bearing or seals fail eventuly, thats not to say it couldn't mind ! Good idea to check the actual temp, its sometimes a case of just how hot is hot
    Also is the new stat working correctly ? Does the top hose remain cold then get hot suddenly as the stat opens, I've seen a few new stats that do not fully close once open. Pop it in a kettle & boil the water, checking the temp it opens/closes at

  8. #8
    davids
    Guest

    Re: IH 685 water pump failing?

    Thanks for the replies I will look a bit deeper next week. Could be that the gauge is giving a false Hot reading and that the stat is not getting hot enough to open fully or at all. The stat that I removed (which opens in a boling kettle by the way) has a small bleed hole about 3mm diameter in the flange which would possibly let enough hot water through to warm the top hose and radiator but not enough to flow right down and round the system??
    recon the first job is to remove the stat and see if I get a flow through the rad without it??

  9. #9
    ReidyNZ
    Guest

    Re: IH 685 water pump failing?

    Quote Originally Posted by Gapples View Post
    I've never seen an impeller come off one of those water pumps, normally its just the bearing or seals fail eventuly, thats not to say it couldn't mind ! Good idea to check the actual temp, its sometimes a case of just how hot is hot
    Also is the new stat working correctly ? Does the top hose remain cold then get hot suddenly as the stat opens, I've seen a few new stats that do not fully close once open. Pop it in a kettle & boil the water, checking the temp it opens/closes at
    Same as that - deffo check thermo, had many a one not work from new - have had more than me share of impeller probs, but as above not had one of those one's, always a first time

  10. #10
    Howburn
    Guest

    Re: IH 685 water pump failing?

    Quote Originally Posted by davids View Post
    Ive changed the thermostat and flushed the radiator and engine block and it all flows fine and the fan belt tension is OK

    You can have good flow through the radiator but you can still have a partial blockage reducing cooling capacity, difficult to diagnose but you can somtimes tell if some areas are warmer than others.


    does any one know if the impeller is likely to have corroded / come adrift have you come across this before?. Ive had a quote for a new pump which isnt expensive but would like to know if this is likely before i take it all apart

    May be worth checking.

    Cheers
    Quote Originally Posted by davids View Post
    Thanks - Thats a good idea when i get back I will try feeding the thermocouple from my multimeter in through the top hose clip and see how hot the top end really is. maybe i`m panicking about nothing!! in fact the top hose never seems to get overly hot to the touch and the radiator cap is never under pressure when removed

    Is the radiator cap sealing? There should be a build up of pressure.

    even when the engine has been running for some time so a double check on the temperature might be a good idea
    Hope this helps

  11. #11
    davids
    Guest

    Re: IH 685 water pump failing?

    "Is the radiator cap sealing? There should be a build up of pressure."

    good point just checked it and found the vacuum relief valve in the centre is not sealing so that needs replacing for a start!

    I think from looking at it that a 9lb series 3 landrover one will probably fit??

    will try to chech the actual temperature at the end of the week and update on how i get on.

  12. #12
    davids
    Guest

    Re: IH 685 water pump failing?

    Thought you might like an update on this

    Put the digital thermometer in the top hose at the weekend and found that even when the gauge is reading off the scale the water temp is only about 78 degrees so not hot enough to open the stat and allow water flow through the rad. with the stat removed the water flows well through the rad so thumbs up for the pump and the rad core

    The radiator cap wasnt sealing which explains the lack of pressure and now ive fitted a new one the radiator has developed a small leak, where somebody in the past has used some kind of radiator putty on it!! i think if rad weld doesnt fix it I will try a solder repair or getting it re cored. (unless any one has a cheaper suggestion?? any body got a spare radiator??.

    any way happy that the engine isnt overheating now wondering if its the sender or the gauge which is at fault

  13. #13
    Huffy
    Guest

    Re: IH 685 water pump failing?

    It sounds to me as if the sender has gone open circuit !
    As I understand senders , as the temp rises it causes the sender to feed more and more current to the guage which in turn causes the guage to move upwards ,(measuring that current , effectively )

    I would simply get a sender to match your guage , making sure its matched , and not any old sender . It wont be much ,and , more likely than a broken guage

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