Brad Bennett
I have a customer with the above unit model 98A00127 The water pump was replaced 2 years ago by competition. It has run hot ever since. It used to run around 175 to 180F. It now runs 225F+ under full load with a load bank.
Does this engine have a water pump bypass? There is not a bypass hose that I can see. I checked with Napa and they show a bypass hose available for this engine. The water pump inlet hose sucks in the more load I put on the engine and the radiator cap releases coolant to the overflow tank. I put a new cap on and it still overflows and the suction hose still sucks in. At low loads it still sucks in. The coolant looks clean and from what I can see the radiator coolant passages look clean. I saw a picture of a 350 with a bypass built in internally with a seperate gaset for the bypass. Is it possible they put the wrong pump on without internal bypass and this pump needs the external bypass hose added. Any ideas would be appreciated. Thanks.
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ohmslaw
I do not believe water pumps ever get bypassed. thermostats get a by pass to allow water circulation. The intake hose typically would have a spring inside to stop it from collapsing. I would think that your thermostat or radiator is suspect. I assume the fan is turning properly and the belt is tight.
Tim
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VHF
When you says the inlet hose sucks in is it just a slight deformation or it nearly collapsing? Maybe the spring is missing thus allowing the hose to collapse and restrict coolant flow.
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bronco
This unit does not have a bypass hose. Ohmslaw has it right t-stat or rad.
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vet327
Had that problem on a truck one time . Talked to my mechanic and it turned out to be( air lock) . to cure it remove the radiator cap and run it until thermostat opens and the fluid runs thru the system then replace the cap and see what happens.
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ceb58
Could be some or all of the above. Or the wrong temp thermostat was installed at pump replacement or if it ran hot before the pump was replaced the head gasket could have blowen. I have seen them blow out between water jackets. Would never get water in the oil but it would run hot.
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ohmslaw
A collapsed hose will cause the over heat also. Question is why is it collapsing. Weak hose, no spring plugged radiator? I would pull the stat and run it. Coolant loss indicates an accurate gauge. I also would replace the lower hose. A question for the units owner would be why was the pump replaced? Was the unit leaking or overheating. The pump may have been replaced needlessly.
Tim
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Brad Bennett
I haven't been back to the site since I posted this. But I think part of the wp suction hose has a spring and part of it doesn't. It also has two hoses on the wp suction. The part that doesn't have the spring is where it is colapsing. There is a T in the line where the block heater is tied into the wp suction. That T is where the two wp suction hoses are. Also what I mean by bypass is where the wp bypasses into the bottom of the thermostat housing. I think like the gm 454 7.4L gas has a bypass, just curious if this unit is supposed to have one. Thank you all for your input and more is appreciated.Thanks,Brad
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ohmslaw
Brad Bennett;8607 wrote:
I haven't been back to the site since I posted this. But I think part of the wp suction hose has a spring and part of it doesn't. It also has two hoses on the wp suction. The part that doesn't have the spring is where it is collapsing. There is a T in the line where the block heater is tied into the wp suction. That T is where the two wp suction hoses are. Also what I mean by bypass is where the wp bypasses into the bottom of the thermostat housing. I think like the gm 454 7.4L gas has a bypass, just curious if this unit is supposed to have one. Thank you all for your input and more is appreciated.Thanks,Brad




My guess is who ever cut in the block heater removed the spring section.
I would replace the hose and make sure the new one has the spring. The hose collapse is enough to cause your problem. You could change the tstat to be safe but this will not help with the diagnostics.Doing one thing a time is better.
Tim
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coreyb38
it sounds to me like you could have a couple off problems i remember the 60kw units had a low temp alarm that would go off when unit was started we lost the contract before we figured a solution but the reason was it was designed for warm climate use actually manufactured in Australia and cat picked it up and put there name on it as well part of the solution process was to actually move the block heater to different locations which of course did not work well in turn i think some of the fans may have gotten flipped during cooled weather and was supose to be flipped back during warm weather now if some one changed the water pump tring to cure an over heating problem and put the fan back the way they took it off then that could be it just a thought
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Brad Bennett
Thank you all for your input. I still haven't been back to the site yet as the customer hasn't given us the approval yet. I'll let you know what happens. Thanks again,
Brad
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bronco
I forgot about the fan make sure it is blowing air out of the unit not in.
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