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Valve question

What is the purpose of this valve?  How does it function?

What indications that it needs to be replaced?

Thanks!

Doug
Doug & Meyka Paddock
1996 U295

Re: Valve question

Reply #1 –
That controls PSI/flow from the engine driven hydraulic pump to the cooling fans for the CAC and radiator.

Overheating would be one symptom of failure.

It could also fail in the fully ON position and MPG and HP would suffer.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Valve question

Reply #2 –
Doug,  That is the thermostatic valve from Source Engineering to control the hyd cooling fan speed.  My 1995 already had one and my 2001 now has one that I installed when the electronic control failed on HIGH.

These are very reliable and long lived.  But if failed, fans would be on HIGH. This means they run on high when the engine is just started after sitting over night.

Call Source Engineering as they are very helpful on phone.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Valve question

Reply #3 –
I did an inframe rebuild due to pitting on the piston sleeves.  Discovered by oil in coolant and vice versa.

Still getting some oil in coolant but no water in oil.

Could this be the culprit?
Doug & Meyka Paddock
1996 U295

Re: Valve question

Reply #4 –
Quote from: Dougpad –
I did an inframe rebuild due to pitting on the piston sleeves.  Discovered by oil in coolant and vice versa.

Still getting some oil in coolant but no water in oil.

Could this be the culprit?

No.  That valve is in coolant, but the hoses have hydraulic fluid. Not connected to engine oil system.

Were it to leak, you would have CLEAR oil in the coolant vs black if the leak is from the engine oil.

And perhaps coolant in the large black hydraulic reservoir for hydraulic fluid.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Valve question

Reply #5 –
Thermostat wax valve that open and closes with coolant temperature to regulate fan speed by restricting oil flow to increase fan speed. Under the cap with the Allen head socket there is a adjustment for base fans speed for inlet air temperature control of the CAC charge air cooler. Oil if from hydraulic pump shared with power steering
Scott

Re: Valve question

Reply #6 –
Thanks everyone.  That is obviously not my culprit. 

Doug & Meyka Paddock
1996 U295
 

Re: Valve question

Reply #7 –
Getting all the residual oil out of a contaminated cooling system is very difficult.

May take a whole roll of paper towel, a small piece at a time. 

As coolant circulates, the oil will migrate to the top of components.  Removing the radiator cap will expose one (small) area where the oil can collect.

Gently placing a piece of paper towel on the surface will remove the oil film on the top.  Repeat after running the engine the next time (once it has cooled down) to remove a little more oil.

In worse cases, the radiator will need to be removed and cleaned.  Assume they cleaned the inside of the engine when it was open.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020