Ford 555 water pump pressure

[Mike industrial tractor]

Hello;
I had some overheating issue with my 1978 ford 555 2.3 litre diesel. I wondered if anyone knew what psi this system should use for rad cap pressure as I can’t seem to find it in the manual ( if you’ve seen this in the 555 manual please let me know what page).
I removed the thermostat however still don’t see much flow. There is very little movement of water very sable so was looking for a better test if water pumps working….
I wondered if there is a good port on the tractor to hook up a pressure gage to check if water pump is working to pressure.
Thanks

 

[mhb@ufe]

Hello;
I had some overheating issue with my 1978 ford 555 2.3 litre diesel. I wondered if anyone knew what psi this system should use for rad cap pressure as I can’t seem to find it in the manual ( if you’ve seen this in the 555 manual please let me know what page).
I removed the thermostat however still don’t see much flow. There is very little movement of water very sable so was looking for a better test if water pumps working….
I wondered if there is a good port on the tractor to hook up a pressure gage to check if water pump is working to pressure.
Thanks

Water pumps do not create the pressure in the cooling system. The pressure is created by the rising temperature of the coolant. It's possible the thermostat is stuck closed preventing flow.

 

[Bern]

Water pumps do not create the pressure in the cooling system. The pressure is created by the rising temperature of the coolant. It's possible the thermostat is stuck closed preventing flow.

Actually, water pumps do create pressure, hence the name "water pump". If they didn't, you'd never get water into your heater core or through a coolant filter.

 

[Bern]

Hello;
I had some overheating issue with my 1978 ford 555 2.3 litre diesel. I wondered if anyone knew what psi this system should use for rad cap pressure as I can’t seem to find it in the manual ( if you’ve seen this in the 555 manual please let me know what page).
I removed the thermostat however still don’t see much flow. There is very little movement of water very sable so was looking for a better test if water pumps working….
I wondered if there is a good port on the tractor to hook up a pressure gage to check if water pump is working to pressure.
Thanks

Normally I'd say install a 0-30 PSI pressure gauge into the sending unit port and look for a minimum of 10 PSI or so at full throttle. That said, I don't think you'd get much of anything with the thermostat out, as it creates about the only resistance to flow that the pump provides. If you see very little water movement with the t-stat out, I'd say don't waste your time putting it back in and doing a pressure test, you likely have a worn pump.

 

[Tom in Mo.]

I'm sure you meant the 3.3L 3 cylinder engine. On page 80 of my Operators Manual it shows:

 

[Tom in Mo.]

The pump is a circulating pump but the temperature of the water at operating temperature is what creates the pressure behind the cap in order to raise the boiling point of the coolant.

 

[Bern]

The pump is a circulating pump but the temperature of the water at operating temperature is what creates the pressure behind the cap in order to raise the boiling point of the coolant.

The pressure behind the cap is created as a result of the water temperature rise. In addition to that, the pump itself generates pressure even with the cap off or not factored in. If it didn't, there'd be little to no movement of water within the system. If it didn't, there'd be little sense installing a water filter.

In summary, pressure in the cooling system is generated two ways, one by the heating of the water and expansion of the coolant, and two by the pump itself moving water in the system against a restriction known as the thermostat.

 

[Btzj02]

I would suggest that pumps are designed with a certain discharge head vs discharge volume of, in this case, water. A water pump on these tractors are designed with very low head pressure discharge and a high volume of water flow. I agree that to circulate any fluid a difference in pressure is required. Things flow from High Pressure to low pressure. I think what people are saying is that the operating pressure in the radiator is not caused by the pump but, it is caused by the heating of the water, which I agree. Very old low horse power engines had no water pumps and strictly relied on a thermal syphon to circulate water. Hot water rises and cold water sinks. When trouble shooting these tractor pumps I don't think the discharge pressure of the pump is important. If it circulates water with the radiator cap off, it will circulate water when the radiator cap is on.

 

[JMOR]

I would suggest that pumps are designed with a certain discharge head vs discharge volume of, in this case, water. A water pump on these tractors are designed with very low head pressure discharge and a high volume of water flow. I agree that to circulate any fluid a difference in pressure is required. Things flow from High Pressure to low pressure. I think what people are saying is that the operating pressure in the radiator is not caused by the pump but, it is caused by the heating of the water, which I agree. Very old low horse power engines had no water pumps and strictly relied on a thermal syphon to circulate water. Hot water rises and cold water sinks. When trouble shooting these tractor pumps I don't think the discharge pressure of the pump is important. If it circulates water with the radiator cap off, it will circulate water when the radiator cap is on.

I think all the responders know what you have summarized and just want to jabber/ argue. If wanting to verify the pump, look at flow volume, not pressure. Take hose loose and crank it up.

 

[Mike industrial tractor]

Thanks everyone. Yes I meant the 201 cid 3.3 litre 3 cyl diesel. Thanks for the 7psi spec as mine has a 15psi cap on it. Was yours the same year? My service manual seems to list everything else however seemed to miss this spec.
Also for the cost of the pump I think I’ll take your advise and just put a new one on as suggested. Thanks again for replying. Have a good day!

 

[kz1000]

You guys are putting him under a lot of ----pressure!

 

[Sean in PA]

The only pressure created by the water pump should be when the thermostat is closed, and that pressure should not reach the radiator cap. Once the thermostat is open, the coolant is flowing and so the the pump should not build much pressure at all. Pressure from pumping a fluid is only achieved when there is a resistance to the flow. Pressure at the radiator cap is from increased pressure in the system due to a rise in temperature.

 

[Mike industrial tractor]

Just an update; So I went to order a 7 lb cap however they told me I need a 14 lb cap for the 1978 ford 555 tlb.
Thanks
Mike

 

[Sean in PA]

Just an update; So I went to order a 7 lb cap however they told me I need a 14 lb cap for the 1978 ford 555 tlb.
Thanks
Mike

Who is "they"? The parts site lists a 7 lb. cap as standard and a 13 lb. cap for "Tropical" use.

 

[Mike industrial tractor]

Thanks again for the replies. Tropical was the problem so I got the right cap on order..

 

[wore out]

Thanks again for the replies. Tropical was the problem so I got the right cap on order..

Going to a lower pressure cap will do NOTHING to alleviate an "overheating issue", I'm CLUELESS as to what you think will be solved by that?

The only POSSIBLE benefit of a lower pressure cap is to put less stress and strain on an old radiator and hoses, etc..

 

[chris142]

Actually, water pumps do create pressure, hence the name "water pump". If they didn't, you'd never get water into your heater core or through a coolant filter.

water pumps do NOT make pressure. Instead they suck coolant, dont push.

 

[Sean in PA]

I am wondering if you are experiencing coolant being pushed out due to overfilling the radiator. Do not fill it to the neck where the cap sits. Only fill it to a half inch to an inch or so above the core and leave most of the head of the radiator empty. That allows for expansion of the coolant as it heats without forcing any coolant out of the overflow unless it really does overheat.

 

[Mike industrial tractor]

I only went to the lower pressure cap as I have now taken the rad in for an internal external cleaning, replaced the water pump, put in a new thermostat and added the fan shroud that was not present, so I thought I would go all original. I haven’t tried it out yet however am hoping my overheating issue is over. I’ll post again once I’ve tried it out. I will indeed not
overfill it to leave room for expansion.
Thanks to all for the help!! Have a great day.

 

[Mike industrial tractor]

I'm sure you meant the 3.3L 3 cylinder engine. On page 80 of my Operators Manual it shows:View attachment 68388

Hi Tom; does your operators manual also list the hydraulic oil type and the filter spec? My service manual covers both the 550 and 555 and lists oil spec as M2C48A and just says filter is 10 micron throw away. Just curious because I’ve seen other 555’s say oil spec is M2C134D although maybe they are not the 1978 model year.
Thanks
Mike