Coolant leaking into cab from heater box ?

[wiersema07]

Bought a 90 m931a2 today And while driving it coolant appears to be coming in from by the heater box on passenger side and coming on floor board on cab. Owner said it was because he just over filled the reserve tank and was wondering if that will actually happen or if any one has had this happen. Also noticed it coming down from by the reserve tank on passenger side dripping down
Thanks

 

[rtk]

sounds like a heater core leak , do a pressure test and it should be easy to locate the leak . I would also think about a coolant flush and change once you get the leak fixed .

 

[wiersema07]

sounds like a heater core leak , do a pressure test and it should be easy to locate the leak . I would also think about a coolant flush and change once you get the leak fixed .

I was planning on installing a block heater this weekend and already have new coolant to do the flush. I can tell after looking at it on the inside it’s coming bottom of the floor vent of heater box inside but didn’t have the day light to check under the hood and see. I’ll have to get a pressure test kit and see where it’s leaking.

 

[simp5782]

Heater core is in the engine bay area. There is nothing in that could put coolant in the cab besides that.

There is a civilian equivalent to use to replace it. Calls for some offset slots to be cut in the. Core box for the new heater fittings

 

[wiersema07]

Heater core is in the engine bay area. There is nothing in that could put coolant in the cab besides that.

There is a civilian equivalent to use to replace it. Calls for some offset slots to be cut in the. Core box for the new heater fittings

OK ill take a look i think im just going to shut the valve until i have time to evaluate it further. im not worry about not have heat for while until can look it over. been 6 years since worked on a 5 ton, so im a little rusty on getting re educated. i appreciate your response and will look into it more this weekend when i do the exhaust and block heater.
thank you again !

 

[ericp351]

OK ill take a look i think im just going to shut the valve until i have time to evaluate it further. im not worry about not have heat for while until can look it over. been 6 years since worked on a 5 ton, so im a little rusty on getting re educated. i appreciate your response and will look into it more this weekend when i do the exhaust and block heater.
thank you again !

Quick note- 1980's "fox bodie" ford cores are nearly a direct drop in and easy to get. Those were Mustangs, small LTD's, Fairmounts, et cetera.

 

[wiersema07]

Quick note- 1980's "fox bodie" ford cores are nearly a direct drop in and easy to get. Those were Mustangs, small LTD's, Fairmounts, et cetera.

Thank you !!

 

[Steelreaper80]

OK ill take a look i think im just going to shut the valve until i have time to evaluate it further. im not worry about not have heat for while until can look it over. been 6 years since worked on a 5 ton, so im a little rusty on getting re educated. i appreciate your response and will look into it more this weekend when i do the exhaust and block heater.
thank you again !

I had the same problem. There are direct replacements on army truck part supplier sites. Very easy to swap out.