With help from Windecker and P Whittle, I rebuilt my Sauer Danfoss CPB 1033 hydraulic pump. My pump was producing good pressure, but it was pulling transmission fluid into the hydraulic system and then venting hydraulic oil out the back. Allison Transynd is up to $60 per gallon, so I decided to fix it.
Last year I replaced the two small -4 lube hoses that go from the trans to the PTO. They had rubbed on the side of the trans and were leaking. Make sure you check yours. I zip tied some split fuel line over the new hoses to prevent rubbing.
I raised the coach up as high as it will go on the air bags and put my jack stands under the rear frame.
The hardest part is breaking loose the large hydraulic hoses. The steel fittings had some corrosion inside and they are tough! The bottom intake hose takes a 2" wrench. It took two of us pulling on that huge wrench for about 20 min to loosen it. Then we drained almost 14 gallons of Dexron III out of the bottom hose into 5-gallon buckets.
The top two pressure hoses are 1 5/16" and my jumbo wrench set did not have a 1 5/16" wrench. I had to go buy one. Even with a new wrench, it took some persuading with a large hammer to break these hoses loose.
Once you remove the hoses, then there are just two 3/4" hex head bolts holding the pump onto the PTO. These came out easy.
Then the pump just slides forward on the splined shaft and you lift it out. To disassemble the pump, there are eight studs with 11/16" hex nuts on each end. You will need a long handle ratchet on one end and a wrench on the other end. Then the pump sections pull apart. Make sure you mark the sections so you can put it back together the same way.
Since my pump was pulling transmission fluid from the PTO into the hydraulic side, the main thing I needed to change was the front shaft oil seal. There is a snap ring holding the seal in. Once you remove it, the seal will push out from the back side. Thanks to Paul for loaning me his seal insert tool. This made it easy to tap the new seal into place and then replace the snap ring.
The rest is replacing various o-rings in the pump (Paul and Will are the experts at this). Make sure you are careful and lay everything out the way it goes back together. I used some transmission assembly petroleum jelly to hold all the o-rings in place and applied ARP bolt lube to the studs. I reassembled all the parts and torqued the eight studs to 50 ft lbs.
I installed the new pump to PTO gasket on the pump face with some Permatex Ultra-gray.
Next I reinstalled the pump by sliding the pump input shaft back into the PTO housing and installing the two retaining bolts. I left the two mounting bolts loose to make it easier to start the hose end ends. I applied some anti-seize to the hose fittings. I then tightened the two mount bolts and the hoses. I added eight gallons of Dexron III hydraulic oil to test the system. No leaks so far!
Now I need to top off the fluids and test it on a good hill.
List of parts and tools (this is for a Cummins ISX in a 2004 Monaco):
Cummins PTO to Hydraulic pump gasket- Cummins #3916042 (eBay)
2” combination wrench for lower hose
1 5/16” combination wrench for upper hoses
¾” combination wrench
11/16” combination wrench
Ratchet with 11/16” socket
Snap Ring pliers
Pump rebuild kit- Call Gary Manchester, 708-887-6320
Can of engine degreaser & can of brake clean
Trans Assembly Goo from Amazon-
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I purchased Dexron II at Walmart for $14.94 per gallon.
A friend who preferably is a weight lifter. You will embarrass him when he tries to loosen those hoses!
Hope this helps!
Will has some better pictures posted here:
http://www.irv2.com/forums/f115/saue...-444138-4.html
The pump pictures turn sideways when posting.