[jdkskyking]

Spent the morning cleaning out the header tank. Scale buildup and rust! Not fun to remove. Used a pressure washer and finally got rid of the junk. I’ll post pics later. A updated tank is in the future. 

Replaced thermostat with a genuine Caterpillar Water Temperature Regulator and updated temperature sensor. 

Using Caterpillar engine cooling system cleaner and distilled water, I ran the engine for 1.5 hours. 
The engine achieved and stabilized at 190*. 

I had closed the dash heat manifold valves. After an hour of running the engine I opened the valves. The engine temp dropped and eventually recovered and stabilized. 

I’m confident the engine thermostat contributed to the cooling issue. 

I drained the cleaner from the system and have filled it with distilled water. Tomorrow I’ll run the engine to operating temperature, drain, and add new Cat ELC. 

On the Hydraulic Fan front... I replaced the valve that is used to adjust system pressure and returns fluid to the reservoir tank. Until I drive the coach I won’t be certain if there’s a difference how the fan and radiator perform. 

Long and productive day, I’m glad Richard talked me in to working the problem myself. 
JK

The hydraulic manifold has a spool valve controlled by a 12v electric solenoid controlled by the engine ECM. The spool valve determines cooling fan speed, high or low. The CAT-13 ECM removes the 12v at 217° coolant temp. This allows the fan to run on high until coolant temp is reduced. 
There is also a logic valve in the system that prioritizes hydraulic fluid flow between the fan an gearbox. 
There are two pressure relief valves that return fluid to tank, a RV5 and RV6. 
The RV5 valve should be set to 2500 psi to protect the entire hydraulic system. The RV6 valve protects the gearbox and should be set to 2000 psi. The gearbox also has internal pressure relief system.

[jdkskyking]

I started this thread in October 2020 because my engine got hot climbing a grade in Colorado. 

We’re lucky to have the Newellgurus site as a Time Machine so we can see where we were compared to what we know today. 

Nuts and bolts of my problem and maybe yours… you may not know it… 

I do not have a big enough hydraulic pump (VICKERS V20) to properly operate a ZF Steering Gearbox AND the cooling fan hydraulic MOTOR. 

The cooling fan was set at minimum pitch because of the limits of the V20 pump. More pitch needed, upwards of 30° to pull enough air through the cooling stack AND push the HOT AIR out of the back of the engine compartment. My hydraulic system ran on high ALL OF THE TIME. Some Gurus know the negative impact to the steering gearbox circuit when the system goes to or is always in high speed… 

How am I resolving this problem??? 
Slowly and expensively…. that’s how… and lots of headaches. I’ve replaced the radiator and CAC which improved the situation but still “masks” the root cause of the problems. 

So far I’ve added a PTO Drive to my Allison 4000 which will drive the new hydraulic pump. That’s a story in its own, I had to purchase a used transmission to get the housing and gears needed to drive the PTO. This was the first major milestone to the modification. 

Recently I had a new hydraulic tank fabricated. I need a 2” feed for the new pump and lots of return ports for the new control equipment to make everything work. 

What’s next? Finally getting to take a vacation in my Newell… after that it will be time to complete the modification… new pumps, control equipment, and hoses…. 

Here’s the new tank. 

                   

I had the tank fabricated in Miami, OK by a shop whose owner is a previous Newell employee. 

I’ll also have him fabricate a new coolant header tank but that’s down the road.

[arcticdude]

Are you using a dry (grease fitting) pto or a wet lubed pto? Our Wanderlodges have a nasty fretting of the gears that occurs without proper lubrication. Frequent greasing seems to work to minimize the issue. The wet lube is also supposed to minimize it, though I’ve not followed it in recent years to see what long term outcomes were.

What are you planning for filtration of you new hydraulic system?


Looks great so far!

[jdkskyking]

I had a Chelsea 267 PTO installed. It uses transmission fluid to lubricate the PTO drive to hydraulic pump. Fingers crossed!

[arcticdude]

Good! That looks to be the larger input shaft version, which also supposedly decreases the fretting issues. I hope it solves all the hydraulic issues without adding anything more!

[jdkskyking]

Quick update/reminder about my ongoing project. 

It’s been many years since I started this journey and I’m starting to bring it all together.

The project will resolve several intertwined problems and challenges.

My 2005 Newell with a Cat 13 ACERT and Allison 4000 transmission. 

A single hydraulic pump, VICKERS V20 to supply the ZF Steering Gearbox and Cooling Fan Hydraulic Motor. 

FACT: The V20 does not provide the hydraulic system with the needed flow to operate the two components. 

Resolution: Split the system. The engine driven VICKERS V20 supplies the ZF Gearbox only. 
Add a hydraulic pump for the cooling fan hydraulic motor circuit driven by a transmission mounted PTO. 

I’m getting closer to achieving my goal. 

   

   

The WHY…

In reality, the ZF Gearbox needs a dedicated hydraulic pump (flow) to function “properly”. What is properly? Continuous hydraulic flow irregardless of the wants and needs of a cooling fan circuit… I’m confident the ZF Gearbox performance, the “feel” going straight forward will improve… less hunting… 

In reality, the cooling fan blades need to be “pitched” properly to draw air through the radiator stack and provide enough airflow through the engine bay and out the rear hatch to prevent excessive heat buildup. Final blade pitch will be 30° up from the original setting of 20° (due to the limitations of a single hydraulic pump expected to serve two systems). 

Theory and Reality… Pain and Suffering… Practical Application…

The $tory of my Journey… 

Live and Learn 

More to come. 
JK

[[email protected]]

Quick update/reminder about my ongoing project. 

It’s been many years since I started this journey and I’m starting to bring it all together.

The project will resolve several intertwined problems and challenges.

My 2005 Newell with a Cat 13 ACERT and Allison 4000 transmission. 

A single hydraulic pump, VICKERS V20 to supply the ZF Steering Gearbox and Cooling Fan Hydraulic Motor. 

FACT: The V20 does not provide the hydraulic system with the needed flow to operate the two components. 

Resolution: Split the system. The engine driven VICKERS V20 supplies the ZF Gearbox only. 
Add a hydraulic pump for the cooling fan hydraulic motor circuit driven by a transmission mounted PTO. 

I’m getting closer to achieving my goal. 





The WHY…

In reality, the ZF Gearbox needs a dedicated hydraulic pump (flow) to function “properly”. What is properly? Continuous hydraulic flow irregardless of the wants and needs of a cooling fan circuit… I’m confident the ZF Gearbox performance, the “feel” going straight forward will improve… less hunting… 

In reality, the cooling fan blades need to be “pitched” properly to draw air through the radiator stack and provide enough airflow through the engine bay and out the rear hatch to prevent excessive heat buildup. Final blade pitch will be 30° up from the original setting of 20° (due to the limitations of a single hydraulic pump expected to serve two systems). 

Theory and Reality… Pain and Suffering… Practical Application…

The $tory of my Journey… 

Live and Learn 

More to come. 
JK

So the transmission requires an external hydraulic pump? WTH? 

Never did much with any ZF big stuff, have worked on smaller ZF transmissions.

[Richard]

No the trans does not require an external pump. Jeff has added a pump to the trans. So now he has two hydraulic pumps. One each to supply the hydraulic fan circuit and another to supply the steering gear box. In later model years Newell began to use a setup like this for all the reasons that Jeff has elucidated.

[jdkskyking]

A ZF “Transmission” was not designed for a Power Take Off option, only an Allison transmission. 

The Allison Transmission that my coach came with did not come equipped with the option to mount a PTO. 

I purchased a used/salvaged Allison transmission that included the necessary parts to modify my transmission. The Allison shop in Springfield Missouri did the work. This modification lengthens the transmission by 4”. The drive shaft also was modified. The extra length did not negatively impact the geometry of the driveline. 

   

   

   

   

In my motor coach, “I am of the opinion”, that the only way for my engine cooling system to function normally AND for the ZF Steering Gearbox to function as designed, each system must have a independent hydraulic pump supplying hydraulic fluid flow. 

The two pumps will share the same hydraulic reservoir, hydraulic filter, and hydraulic cooler otherwise, the pumps operate independently of each other. 

Engine driven VICKERS V20 for ZF Steering Gearbox.

Allison Transmission/Chelsea PTO/ DANFOSS X20 Hydraulic Pump for Multi-Wing Cooling Fan Hydraulic Motor. 

Someday I’ll summarize the entire journey and tie it all together. I know the recipe for success for my bus. Richard has been along for the ride as well. 

JK

[[email protected]]

No the trans does not require an external pump. Jeff has added a pump to the trans. So now he has two hydraulic pumps. One each to supply the hydraulic fan circuit and another to supply the steering gear box. In later model years Newell  began to use a setup like this for all the reasons that Jeff has elucidated.

I know where I went wrong, he said ZF gearbox and I assumed transmission, he is talking about the steering gearbox. 

Thanks for the summary Richard, if I would have read the entire thread I would have known he has an Allison transmission. 

So this is good to know, I think I may be having a similar issue with mine. I have been getting some whining noise from my pump and occasionally my steering goes "dead", no power assist. I attributed the issue to the fact that my hydraulic filter looked like it had never been changed, appeared to be an original vickers brand filter that was in bad shape. First thing I did was change the filter, but no change in the whining or the dead power steering issue. I did however gain a leak at the pump now. Some of this was from when I loosened the line. I tightened the line some more and it reduced the leak on this last trip to Tennessee but I still have a leak. I went ahead and ordered a brand new pump and I need to get that installed. I will see how things are after I replace the pump. 

I may look into a way to add another pump if the issue persists. If I go that route I may see if I have room to run a 2 section pump instead of trying to add a second pump. Wanderlodge went this route with their coaches as well, the two section pump is effectively 2 pumps in one. Not sure if the gear on the engine can handle this load though, I will have to verify the specs on what can be driven on the engine gear. 

Is there a reason why you went with second the pump on the transmission instead of a 2 stage pump?