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fan hydraulic adaptor overhung seals load

Hydraulic Fan Motor Leak
Interesting thread, the mechanic doing my re-power talked me out of using the hydraulic setup from the donor bus.
"The fan is going to be belt-driven so as to move more air than the hyd system the city bus set up could. I got a fan gearbox from Prevost. Almost done with that and then will pull rad back out and have it recored"

Jon & Chris Everton
1986 40' Dog House #86
450 hp ISM 5 spd ZF Ecomat 2
2004 Range Rover L322 Toad
You should be up and running pretty soon!
(11-30-2021, 07:00 PM)Update.  I am happy to report after 2500 miles, including some 100 degree drives and a few mountain climbs that the grease setup with the OHLA is bone dry. No leakage at all. I will update again when we return home in the fall. Richard Wrote: Well……rats.

The seal started leaking for the third time during our summer trip. ATF really does make a mess. You know the engineers definition of insanity, doing the same thing over and over but expecting a different outcome.

I had some communication with the engineers at Zero Max, the manufacturer of the OHLA. The version we have is a Newell special. They normally come packed with grease, instead of having an flow through lubrication system. Newell did it in a very clever way by routing the drain hose from the hydraulic motor through the OHLA and then routing the outlet from the OHLA to the hyd reservoir. So, taking the OHLA out the loop will mean the case drain from the hyd motor will now go directly to the hyd reservoir. 

But I am tired of cleaning up that mess in the engine bay, so here is my conversion to grease filled OHLA. I used Mobil 1 SHC grease, that is why it is red in the pics.

The first pic is of the OHLA with the original JIC hydraulic fittings. These are kind of different fittings than I knew about, but I learned they are JIC on one end and ORB on the other. ORB stands for O ring boss. It is supposedly a tighter seal, but only if you can tighten the nut to make the seal between the O ring and the case. Picture two shows the old fitting removed. Those marks on the nut are where someone in the past tried to tighten it with a hammer and a punch. No way a socket or wrench is getting in there because of the right angle.

Anyhoo, I replaced the right angle fittings with a #10 ORB plug. I drilled and tapped a hole in both the plugs and installed zerk fittings prior to installation. I removed the drain plug on the top and replaced with a vent plug. I did spring for new seals although that may have been overkill with the grease.

I will provide an update after next years tour of the country.

Oh yeah, one more thing, if you ever try this. The original plug on the top of the case was 1/4 NPT with an Allen recess. After breaking two Allen wrenches, I knew it wasn’t coming out. So I found a big nut that would just fit over the plug, and plug welded the nut to the plug. No problem removing after that. This is technically known in the south as the mo powah technique.
Richard and Rhonda Entrekin
99 Newell, 512
Subaru Outback Toad
Inverness, FL (when we're home Cool )
Richard, Great news.....looks like another project coming my way. When you separated the OHLA from the Hyd Pump, what kind of shaft arrangement is on that end of the OHLA?
Steve & Doris Denton
45' Newell #525, Bath & Half
2014 Honda CRV Toad
Tapered and keyed shaft on the fan hub side. Splined slip fit between the hyd pump and the OHLA.
Richard and Rhonda Entrekin
99 Newell, 512
Subaru Outback Toad
Inverness, FL (when we're home Cool )
engine hydraulic fan is not turning
Should it run at slow speed and speed up as engine
Temp rises?
My fan runs at high speed if I unhook at the control
But nothing at idle I’m I’m
Coach 385
Toad Mini Cooper 
Many of them barely spin at idle. It may or may not spin as you increase RPM. If it goes to hurricane mode when you unplug the solenoid, the control system is working properly.

It does NOT increase speed with temperature UNTIL the Temp reaches 203, then it goes to HIGH. It is a two speed control system, not a proportional one.

Are you overheating?
Richard and Rhonda Entrekin
99 Newell, 512
Subaru Outback Toad
Inverness, FL (when we're home Cool )
Not overheating
I started it up this AM ran at high idle for a while, it’s 
Way hot here, temp on dash gauge went up to 200. 
I walked to rear of coach and didn’t hear fan. I opened
Rear hatch and fan was not turning. I unplugged the wire
To control and fan went to high speed.
I thought fan should be moving???
Coach 385
Toad Mini Cooper 
Dash gauges are notoriously inaccurate.

Fan may not turn on low speed control. Keep in mind air is drawn in radiator and exits rear hatch while going down the road due to low pressure area behind the coach
Richard and Rhonda Entrekin
99 Newell, 512
Subaru Outback Toad
Inverness, FL (when we're home Cool )

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