Leaking Hydraulic Fan Motor

[Alpine Dave]

I just fixed the leak in my CAPS fuel pump and discovered hydraulic fluid leaking from the radiator fan motor on my 1999 Alpine. The fluid is leaking at the output shaft of the motor. The motor is a Sauer-Sunstrand TAM 22-90 (the full stamping is TAM 22-90/26 5 Cl O7 RUL E/7H). I did a Google search and came up with no US suppliers. Has anyone replaced this motor?

I know nothing about hydraulic motors. Some of my questions are: Are the motors available in the US? Are remanufactured units available?
Perhaps all I need is to replace a seal. Are parts available? Are there repair shops that fix these things?

Help with any of these questions would be greatly appreciated. At this point I'm not sure what to do next.

[EngineerMike]

Assuming you are somewhat near home in CO, Berendsen Fluid Power has an office in Aurora, 303-367-1739
They sold the hydraulics by Sauer to WRV out of the Spokane office, 509-535-4281 and they have a "match" program on their computers that will match the motor numbers to the current part#, and they will check inventory across America in their system for that part. They are distributors for Sauer-Danfoss products, the current incarnation of what was Sauer-Sunstrand. Motor may be made by a different subsidiary or affiliate today, but is probably available somewhere in the known world.

An alternative, assuming all else is working according to Hoyle except for the leak, is to remove the motor, and replace only the seal. You should be able to match the seal according to its numbers or its size specs at any of a number of places. I used to take such stuff to Bearing, Belt & Chain, one of those fabulous businesses that have a true specialty & do the most incredible job of being geniuses at the specialty. Gotta be places like that around the country that specialize in seals & such. Find an old farmer near you and s/he can direct you to such a place in your neighborhood.

[HeapBigEngin]

Re the pump, I had to have ours (Sauer-Danfoss) replaced in mid-2010 due to a fairly significant leak at the output shaft seal. Although I have the aptitude for repairing such things, I just didn't have the facilities at my home or our storage facility to do the work....but my local Freightliner dealer did. At that time, I was told by FL that only new pumps were available. Since I could not do the work myself (and look for a hydraulic repair business to replace the seal), I bit the bullet.

Recognize that this is a pretty big job. In our case, it took an experienced RV technician around 7 hours to complete the repair.....and he had the correct tools to do it and worked in a stand-up "pit" beneath the coach, not on his back. Since the repair, all seems well (knock on wood!) Maybe it's just me, but I am not a big fan of using remanufactured parts in a repair where so much labor time is involved because one cannot always be sure of what caused the now-remanufactured part to fail the first time around. In addition, if the reman part subsequently fails, some reman warranties do not cover labor....only the part. Something to consider before going reman if its available.

A side note. On our pump, there are 3 set screws in the pump housing near the output shaft. Each set screw is sealed with an "O" ring. You might check to see that the leak is not coming from one of these. Not so in our case. But it's worth checking....

Good luck, and please let us know how you make out here....thanks!

[Alpine Dave]

Thanks for the input guys. Now I have some leads to check out to get started. The coach is in my garage for the winter, so I have time to work on it. The best I can tell, using a mirror, is the output seal is leaking. The fluid migrates over a large area, but it looks wettest around the circumference of the shaft as it enters the motor.

It does not look like too big a job on my coach to remove the motor. If I can find a local shop that can repair and bench test the motor, I think that will be my first choice. If not, I will consider a new motor or a reman, depending on availability and cost.

The fan seems to work fine except for the leak. But, I know from other posts on the topic, that EngineerMike suggests replacing the the wax plug control unit with an electronic control unit. Do you have any specific recomendations on this Mike? (part numbers, suppliers, procedures, ...). Is the electronic controller a direct replacement, or are modifications required to install it?

Thanks again for the information, Dave

[daveshan]

^ subscribed to make sure I get Mike's response about the controller upgrade.

Good luck with your motor leak Dave.

[stuhly]

Any good hydraulic shop should be able to get seals and rebuild the motor.

[EngineerMike]

About electronic upgrade- that may have been a thought at one time, but I'm not aware of a parts set to accomplish the job. You could probably buy the Sauer-Danfoss controller, install it on the frame where WRV put them (across from the motor, probably need new 1/4" hoses to match for new length), and with significant search & destroy tactics- find the ECM engine heat indicator circuit(s). I have no idea how to find that/those. I'd start w/ Cummins sensor map for your engine (which I recommend everybody have on board); it comes in a fold-out, plasticized format showing all circuits to/from engine and shows graphics of the end connector you are looking for, very handy & about $15, quite a bargain. Controller needs specific inputs for engine heat to put out the PWM signal to the attached proportional control valve that substitutes for the wax valve.

As to the seal issue- there are three potential leak modes: 1) damaged/worn seal, 2) damaged/worn shaft, 3) 1 + 2. Be sure to check the shaft "land" where the seal "lands" on the shaft to see if it has worn a groove in the shaft; if so a new seal may or may not "land" properly to make a seal. If no wear on the shaft, new seals should be fine. If wear, your call on what to replace.

On the ACA Tech Library under Chassis you'll find the hydraulic oil R&R process write up. Should be useful when opening up the system. Check the filters & bottom of oil tank carefully to see if there is evidence of wear in the system someplace as long as you are getting this far into it.

[KSCRUDE]

Originally Posted by HeapBigEngin

Re the pump, I had to have ours (Sauer-Danfoss) replaced in mid-2010 due to a fairly significant leak at the output shaft seal. Although I have the aptitude for repairing such things, I just didn't have the facilities at my home or our storage facility to do the work....but my local Freightliner dealer did. At that time, I was told by FL that only new pumps were available. Since I could not do the work myself (and look for a hydraulic repair business to replace the seal), I bit the bullet.

Recognize that this is a pretty big job. In our case, it took an experienced RV technician around 7 hours to complete the repair.....and he had the correct tools to do it and worked in a stand-up "pit" beneath the coach, not on his back. Since the repair, all seems well (knock on wood!) Maybe it's just me, but I am not a big fan of using remanufactured parts in a repair where so much labor time is involved because one cannot always be sure of what caused the now-remanufactured part to fail the first time around. In addition, if the reman part subsequently fails, some reman warranties do not cover labor....only the part. Something to consider before going reman if its available.

A side note. On our pump, there are 3 set screws in the pump housing near the output shaft. Each set screw is sealed with an "O" ring. You might check to see that the leak is not coming from one of these. Not so in our case. But it's worth checking....

Good luck, and please let us know how you make out here....thanks!

What is the labor and parts cost breakdown on this job? If the labor is very high as it looks to be, a new motor may be the best bang for the buck for the average guy. Many may be able to R&R at home, but out on the road may be a different story. And tow truck, hotel bills and truck shop rates can add up in a hurry. It were me and evening doing the work in my own shop, I would only go with new, if available or rebuilt if not. I never buy rebuilt anything, if new is available. Having to change a starter or alternator two or three times to save a dollar on rebuilt, new is the only way to go. But many items do not come in new, so you have no choice. Most rebuilders do pretty good work anymore.

[HeapBigEngin]

Originally Posted by KSCRUDE

What is the labor and parts cost breakdown on this job? If the labor is very high as it looks to be, a new motor may be the best bang for the buck for the average guy. Many may be able to R&R at home, but out on the road may be a different story. And tow truck, hotel bills and truck shop rates can add up in a hurry. It were me and evening doing the work in my own shop, I would only go with new, if available or rebuilt if not. I never buy rebuilt anything, if new is available. Having to change a starter or alternator two or three times to save a dollar on rebuilt, new is the only way to go. But many items do not come in new, so you have no choice. Most rebuilders do pretty good work anymore.

Re cost, the new motor was almost $1,100, labor was just north of $800. On top of that, there is fluid cost and hazardous material disposal charges in our neck of the woods. It's not a cheap repair, for sure.

One other note re the OP. If you do the repair yourself, recognize that proper balance at the fan can be really critical on these things. On our repair, the tech told me (when I picked up the coach) that he had inadvertently added 2 unnecessary flat washers when mounting the fan. When he test drove the coach following the repair, the vibration that set in about 15-20 miles an hour was awful. He discovered the error, removed the "extra parts"....and the vibration went away. All this from two extra flat washers. Bet he won't do that again!! I pass that along FWIW....take care.

[KSCRUDE]

OMG, that is a high priced motor, and repair. And the fan off balance. You don't want that.

[Old Trucker]

Originally Posted by Alpine Dave

I just fixed the leak in my CAPS fuel pump and discovered hydraulic fluid leaking from the radiator fan motor on my 1999 Alpine. The fluid is leaking at the output shaft of the motor. The motor is a Sauer-Sunstrand TAM 22-90 (the full stamping is TAM 22-90/26 5 Cl O7 RUL E/7H). I did a Google search and came up with no US suppliers. Has anyone replaced this motor?

I know nothing about hydraulic motors. Some of my questions are: Are the motors available in the US? Are remanufactured units available?
Perhaps all I need is to replace a seal. Are parts available? Are there repair shops that fix these things?

Help with any of these questions would be greatly appreciated. At this point I'm not sure what to do next.

Hi Alpine Dave. We also have a 99 Alpine. I have not had this problem. I think someone told me that the fan motor, power steering and Hydro boost for the service brakes all work together. If this is true, I recently learned that all our service brake system parts are the same as on International school buses.
I was able to fine all my braake parts at NAPA & International. Hope this helps,,, just a shot. old trucker

[EngineerMike]

Trucker- the chassis hydraulics are all related, but the fan motor circuit is separate from the brake circuit outside of the pump. The hydraulic pump has two outputs, one for brakes & one for radiator fan motor.
If the Alpine fan motor was ever used on buses, they would have to have been side-rear radiator models. When asking at a supply outfit, that would be the descriptor for finding a match.

[Alpine Dave]

For the "record", I am going to close this thread with the results of the repair.


As EngineerMike suggested I took the the hydraulic fan motor to Berendsen Fluid Power in Aurora, Co. for evaluation and repair (if appropriate). I took the unit in on 11/2. John told me that new motors and parts for the old motors (except seals) are no longer available. He said if all it needed is new seals it would cost in the ballpark of $300 to fix it. If not, they would have to find an alternative motor, wich would cost a lot more. They called me on 11/5 and said that it just needed a seal kit. Unfortunately, the technician broke off 2 bolts while disassembling the motor and they would have to send it to a machine shop to have the bolts removed before they could finish the repair. The machine shop charges would be extra. I told them to go ahead.


Five weeks went by as I called them every week to check on progress. I was told the machine shop still had the motor and there was nothing they could do to speed them up. Finally I told them I was going to drive down to the machine shop myself the next day to see what was going on. Miraculously, they called me back the same day and said they just got the motor back and it would take them a week to order the seal kit and finish the job.


I received an email on 12/13 saying that the motor repair was finished, I could pick it up, and the cost was $680. I emailed back and asked if that ment the machine shop charged, $380 since I was given a $300 estimate for the seal job. Without answering my question, they email me back the original message except the price was changed to $413. I was there within an hour before they changed their minds again.


The workmanship looked very good and externally it looked like a new motor. It took me another 3 weeks to complete the rebuild of my cooling module, so I was not able to test the repair until a few days ago. I am happy to report that the fan motor appears to be working just fine and does not leak. Of coarse, the real test won't happen until my 8000 mi Alaska trip starting in June.


The lesson learned is if you use Berendsen, Denver make sure you get an estimate up front for both cost and time to do the repair. In the end, the long wait for the repair was not a problem since I had plenty of other things to do before I needed the motor. If I had been stranded here, this could have been a disaster.


On a related topic, I decided to order a spare "wax control valve" (PN: HT93SA210A) since I read that these come from England and take over a month to get. (I could just see myself stranded in the Yukon waiting for months for a new valve to be shipped in by dog sled.) It took all of 6 weeks for the new valve to arrive and cost $327 with tax and shipping. But now at least I have a spare to keep with me, which of coarse means now the the old one will never fail.

[daveshan]

Dave,
Where did you source your spare valve? Might just be a good thing to have.