Cat D6b over heating

[Sam1734]

Hello all, I again am back to diagnosing coolant issues with my D6b. Yesterday I fired the ole girl up for a few property repairs, after full checks, Fuel, Oil, Coolant, and gear oils. The machine fired up instantly after sitting for a year and a half and I made progress for about 45 minutes when I notice fluid on the hood near the radiator cap, and instantly I instinctively looked at the temperature gauge noticing it was running about 220-230 degrees F. I immediately lugged the machine to it's parking place and shut it down. I noticed coolant inside the front portion of the engine bay, outside the front of grill, on hood and dripping down to the ground. I instantly thought, check the oil and breather for coolant and contamination. None was found. only in the places first noticed. I put a brand new thermostat in year before after doing head work on the machine. For the first year after the head work the radiator stayed completely full until today when I had to add 2 gallons of coolant. I'm not certain I have a head issue but the situation didn't occur until I began running higher RPMs while pushing brush and trees across the property. I've looked back through all my diesel mechanic books but never experience this before with a diesel. Reminds me of a car on a long family trip the starts boiling over like a thermostat stuck. Any other ideas?
Sam

 

[Acoals]

With clean water clean the leaked coolant up, then blow it dry. Top the radiator off and put a pressure tester on. You apparently have an external coolant leak, you need to figure out where it is leaking first. Radiators, hoses and such are highly probable culprits for the leak you are describing, I wouldn't get excited about heads such just yet.

 

[Sam1734]

Yeah, probably will after this freezing weather. We know the fan pushes air rather than drawing air on these machines, which would explain the coolant on the outside grill, but fluid on top of the hood is the most baffling part to me. I have a water pump seal kit so I may go ahead and do that as soon as I test pressure. I hope it's not the head, the D333C head is very few and far between for this machine.

 

[D5Dan]

I agree with the pressure test/leak detection…

I’d also add once you have side panels off, make sure you don’t have a mouse colony in your radiator area…1.5 years and cold weather…their nest could have killed your airflow, chewed hoses/belts, let alone what their urine/poop does to parts…bright side at least you know they didn’t damage your ECU/DEF systems

I have a D333 too; I’m pulling for you!!

 

[Delmer]

If the pressure test doesn't show any leaks, the next suspect would be a clogged radiator. Unless something obvious, like the fan belt falling apart from age.

For overheating like that, I'd let it run normal speed with no load for a couple minutes to see if the temp drops, even if it doesn't drop right away, a minute or two will equalize the temps somewhat for a better outcome than driving it and then shutting down.

 

[Acoals]

I am seeing the radiator cap as a suspect, but I am not saying that out loud yet . . .

 

[Sam1734]

I just ordered a new radiator cap to knock that suspicion out early, but will be overhauling the water pump and testing the pressure too. Thanks for the replies.

 

[Vetech63]

I'll take water pump for $200

 

[Old Magnet]

D6b is a D333a engine, not a D333c.
a engine has belt drive water pump, c engine is gear drive water pump.

 

[Sam1734]

D6b is a D333a engine, not a D333c.
a engine has belt drive water pump, c engine is gear drive water pump.

I don't know why I said C instead of A, I learn this from you...LOL!

 

[Sam1734]

Could someone cross reference part number 4F2478? My parts manual shows 8H8719 but the part number on the old radiator pressure relief valve is 4F2478. I have removed the valve after checking the leak and determined the radiator cap seal is dry rotted, but PRV is allowing fluid to drain after heating up. Coolant is leaking from upper radiator area and I suspect cap and PRV. No leaking at pump or hoses that I can see. When I removed the PRV it was slightly stuck but compressed easily after freed up.

 

[Nige]

Could someone cross reference part number 4F2478?

4F2478 pressure relief valve services to 5S1218 in its latest form.

8H8719 is the complete Relief Valve assembly including the cover, gasket, PRV, & hardware.

 

[Sam1734]

4F2478 pressure relief valve services to 5S1218 in its latest form.

8H8719 is the complete Relief Valve assembly including the cover, gasket, PRV, & hardware.

Thanks Nige, you never fail!

 

[Nige]

FYI with all the upgrades of the PRV Part Number it may be the case that the 5S1218 (which is the only Part Number available now, all the others are obsolete) requires a different cover to make it work. I've looked everywhere but can't find any conclusive evidence yay or nay, so be prepared.

 

[Sam1734]

FYI with all the upgrades of the PRV Part Number it may be the case that the 5S1218 (which is the only Part Number available now, all the others are obsolete) requires a different cover to make it work. I've looked everywhere but can't find any conclusive evidence yay or nay, so be prepared.

I have found 1 refurbished part on ebay, but not sure about it, it's listed $45. that is the only one anywhere that I can find. the 5S1218 is available much cheaper, but smaller.

 

[Nige]

I have no idea how anyone would refurb something like that particular PRV.

This is the best I can do for the installation. The Parts Manuals only go back as far as D6C.

 

[Nige]

Try searching for 2S2036. Back in the day it was a direct replacement for 4F2478. It has also been discontinued by Cat but may be available aftermarket.

 

[D5Dan]

I went out to my machine this am (68 D5 with the D333) to see/remember the rad cap/PRV setup… looks like our machines run the same PRV cover/cap, along with the same strainer… But my parts listing shows the easier to find PRV. To me it looks the older PRV had a larger metal flange that the cap would bolt thru…the 5S1218 looks to just fit inside the cap…curious if you have any pics of your setup?

Oops, I was looking at the part numbers from Nige’s post and realize that’s a D6C and you have a D6B…

Maybe a swap of PRV cap (5S1211) too??

 

[Nige]

FYI with all the upgrades of the PRV Part Number it may be the case that the 5S1218 (which is the only Part Number available now, all the others are obsolete) requires a different cover to make it work. I've looked everywhere but can't find any conclusive evidence yay or nay, so be prepared.

I found this. Listed as "7S4327 Pressure Relief Valve Group. Provides Field Replacement for 3H3413 Cover" - which if I'm not mistaken is the Part Number of Cover you have on your tractor.
7S4327 includes the 5S1218 Part Number of PRV. It might fit your D6B but I would not guarantee that.

 

[Sam1734]

View attachment 282154View attachment 282152View attachment 282153

I went out to my machine this am (68 D5 with the D333) to see/remember the rad cap/PRV setup… looks like our machines run the same PRV cover/cap, along with the same strainer… But my parts listing shows the easier to find PRV. To me it looks the older PRV had a larger metal flange that the cap would bolt thru…the 5S1218 looks to just fit inside the cap…curious if you have any pics of your setup?

Oops, I was looking at the part numbers from Nige’s post and realize that’s a D6C and you have a D6B…

Maybe a swap of PRV cap (5S1211) too??

Yours looks just like mine.