After Market Hydraulic Oil Cooler? Your Thoughts? (CK20S Manual Transmission)

[rider7767]

My new CK20S is no longer new, now having 60 hours on it. I use the bucket loader for hours at a time digging stumps and moving dirt. After about a hour, I smell hot hydraulic fluid. I used my A/C laser Infrared Thermometer, and I am coming in at 75 Celsius (167 Fahrenheit) on the outside of the transmission case. The ambient temperature was 87 degrees Fahrenheit. The max temp for (According to the service Manual) is 80 Celsius for the MLS valve. So, I am good, but I think extra cooling would make the system last longer. The CK20S HST has a cooler, but the manual transmission does not. I am thinking about adding a hydraulic cooler in the engine compartment running off of the Power Steering return line. The return line is low pressure and looks to be 5/8" Transmission Hose. It runs from the Steering Control all the way back to the common sump. I can't see it hurting anything, but I can see it helping. What are your thoughts? :scratchchin:

 

[murphy1244]

Go for it! Might add some life to it.

 

[rider7767]

Go for it! Might add some life to it.

Thanks Murph! I think it would protect the oil from breakdown.

 

[RickB]

Decent quality hydraulic/transmission oil isn't going to break down at 167 degrees or anything anywhere near that temperature. In fact, temps in that range will be a great aid in evaporating unwanted moisture that will certainly collect in the oil in some amount.

 

[rider7767]

Decent quality hydraulic/transmission oil isn't going to break down at 167 degrees or anything anywhere near that temperature. In fact, temps in that range will be a great aid in evaporating unwanted moisture that will certainly collect in the oil in some amount.

I agree with you on the oil; however, I am more worried about the MLS valve. According to the service manual, the MLS valve has a max temp of 176 degrees. That seems low to me. Also, this reading was taken on the outside of the transmission case, so I am assuming the actual temp was higher by a few degrees. I think it will be OK either way, but I do work the tractor to the limit right now. After I get a few projects done, it will mow, help cut wood, brush cut a small field, and do yard work. It should have an easier life after the projects. Thank you for your input.:thumbsup:

 

[CJONE]

167 deg C or F. Anyway if you keep temps in the 150 deg f range you are good. temps above 190 start to harden seals and higher will cause leaks. I prefer to keep things cool also. A general rule of thumb is 100 deg above ambient. CJ

 

[rider7767]

167 deg C or F. Anyway if you keep temps in the 150 deg f range you are good. temps above 190 start to harden seals and higher will cause leaks. I prefer to keep things cool also. A general rule of thumb is 100 deg above ambient. CJ

CJONE: Thanks for your guidance. I think I am going to add the cooler. I just don't see how it can hurt. I will put pictures when I get it done. Tony

 

[CJONE]

Remember to mount cooler sideways [ports on either left or right side] with the cooler you showed. In on the bottom and out on the top. In a low flow application it will fill and use all the tubes in the cooler that way. Do you know the flow going through the power steering return? That cooler looks small to me. I wish the diagram showed the flow diverted through the power steering system, it is usually low like 2-3 gpm with a priority flow diverter but ????. CJ

 

[Coyote machine]

Mount it in a way that will provide complete isolation and dampening from excess vibration, otherwise it may follow the lead of earlier production factory mounted coolers and be prone to repeated failure.