Hencho 1 #1 Posted June 28, 2020 Hello all, I screwed up and let the automatic transmission fluid get too low in my model 875 and now it’s not working. I added fluid jacked it up and ran it for 10-15 minutes. The wheels turn but with no power. I checked the bypass valve, closed tight. Does anyone have any suggestions? Share this post Link to post Share on other sites
daveoman1966 3,762 #2 Posted June 28, 2020 Take the hydro pump off and rebuild it. You'll probably find some deeply scored soft brass parts (Piston Slippers) that need resurfaced. This isn't so tuff to do, just be meticulous with it and get it right. Resurface the Piston Slippers, Thrust Washer, Charge Pump Housing, and the Base of the pistons Cylinder Block. Use a FLAT surface plate and...using figure 8 motion... progressively sand off the scoring using 220...400...and 1000 grit sand paper. Don't remove excess material...just enough to remove the scoring and scratches. Reassemble using Assembly Oil and install a new filter. I have posted on Red Square the procedure and pics for the overhaul... but don't know where the moderators have included it. SUNDSTRAND HYDROGEAR refurb.docx 2 1 Share this post Link to post Share on other sites
Hencho 1 #3 Posted June 29, 2020 Thanks Dave, Are the TIMKIN seals readily available at industrial supply store? Also where would I be able to get the Sundstrand O rings & case gaskets? 1 Share this post Link to post Share on other sites
roadapples 6,983 #4 Posted June 29, 2020 Check with Wheel Horse Parts and More in the venders section... Share this post Link to post Share on other sites
Pullstart 63,096 #5 Posted June 29, 2020 @Hencho.... Share this post Link to post Share on other sites
pfrederi 17,868 #6 Posted June 29, 2020 (edited) 13 hours ago, Hencho said: Thanks Dave, Are the TIMKIN seals readily available at industrial supply store? Also where would I be able to get the Sundstrand O rings & case gaskets? Check this posting out for seals and O-ring sizes Edited June 29, 2020 by pfrederi Share this post Link to post Share on other sites
Hencho 1 #7 Posted June 30, 2020 Thanks for your help. I’m beginning to believe that I can do this! Share this post Link to post Share on other sites
953 nut 55,771 #8 Posted June 30, 2020 We think you can do it too. The beauty of a is that they used standard off the shelf parts which don't need to be sourced through the dealership. Share this post Link to post Share on other sites
The Tuul Crib 7,337 #9 Posted June 30, 2020 On 6/28/2020 at 10:34 PM, roadapples said: Check with Wheel Horse Parts and More in the venders section... Lowel is top notch! Hope I spelled it right. Share this post Link to post Share on other sites
Hencho 1 #10 Posted August 1, 2020 I finally got the cajoles to take apart my Sundstrand 90-2001 pump. So here are the pictures of the damage. How much material can I remove from these before they need to be replaced? Share this post Link to post Share on other sites
pfrederi 17,868 #11 Posted August 1, 2020 that is not good. Spec for the slippers is not to remove more than .005. However since new ones aren't available (at least for a reasonable price) better to get them smooth even if you exceed the .005. I have taken a lot off some slippers never measured and they worked OK. The pump is cast steel and it is a lot repeat a lot of work trying to get rid of scoring that deep. I spent several hours with wet dry paper on glass for a gouge not quite that deep. You might have a machine shop fill it with weld and resurface. 1 Share this post Link to post Share on other sites
Hencho 1 #12 Posted August 1, 2020 I thought you might say that. I have a mig welder but welding cast iron can be tricky. I have access to a surface grinder so removing material won’t be so labor intensive. I’ll risk welding if you think I’ve really got nothing to lose. Share this post Link to post Share on other sites
pfrederi 17,868 #13 Posted August 1, 2020 (edited) The bottom of the piston block will need work also. There I am not sure how much you can take off before it interferes with fluid flow...There is no spec I am aware of. I took a bunch off my GT-14 pump and it seem to work OK. If you weld make sure you replicate the small V relief cuts at the one end of each slot. Is there a chip or series of chips out of the slipper end of the piston block?? Edited August 1, 2020 by pfrederi Share this post Link to post Share on other sites
daveoman1966 3,762 #14 Posted August 1, 2020 I have a perfectly good CHARGE PUMP HOUSING (with gerotor set) ...and a set of 9 pistons with slippers...all polished and ready for use. Also have: THRUST washer (1/4 thick), SWASH plate, piston retainer ring...etc.. These are all good useable parts, refurbished by hand. Benn doin' this for 30+ years...lemme know what you need. BTW...your BRASS piston slippers are about the worst I've ever seen. I can replace one or all of them...your choice. 1 1 Share this post Link to post Share on other sites
Hencho 1 #15 Posted August 2, 2020 I’m interested. What are you charging for each item and how much if I buy the lot? You can send quote to cutrone@live.com Share this post Link to post Share on other sites
daveoman1966 3,762 #16 Posted August 2, 2020 I am sending you via Email an Excel SS for the part you ask about: PS.. The NEW Cylinder block with Pistons can be had for $1,100.77. The Swash Plate is NEW for only $533.85. 1 Share this post Link to post Share on other sites
stevasaurus 22,863 #17 Posted August 2, 2020 @daveoman1966 Take a look in the Reference Section / Transmissions to see if that thread is in there. If it is not there, let's find it. https://www.wheelhorseforum.com/forum/144-transmissions/ Share this post Link to post Share on other sites
