Martin 2,133 #1 Posted September 2, 2012 worked on the c160 a little today to try and fix a problem that the hydro has when starting to move either forward or back. trans is c160 piston to piston sundstrand with factory hyd lift. everything on this tractor looks to be original to the tractor and doesnt look like has been apart at any time..... ive replaced the plastic cam plate with a good used one, its not perfect, but works as it should, adjusted and fixed the worn out sloppiness in the brake/motion control, and generally got everything outside 'the box' in acceptable order. heres the problem...... start from cold, engine running well, ready to drive, push park/drive brake down, engine revs either low or high (no difference in problem), move direction control slowly forward or backward until full travel, no movement. 1 or 2 seconds later, full movement (instant, violent). in forward..... i couldnt get reverse to do the same as forward, just would not move at all...... at the same time before the trans does anything, the hyd lift is non responsive. once we have movement hyd lift works normal, tractor drives normal, speed of travel is dependent on amount of movement of dcl ( as per normal....) now (once the drive has done its violent engaging thing) as long as i have the engine running ( and pump turning) it works as normal. can move very slow or fast, sometimes its a little jerky, but it works without throwing you off the back of it. stop engine, and start up and we go through the whole process once again. sounds to me like the pump is sticking somewhere, until we get flow and then things are relatively fine. so what do you experts think the problem is? pump or further in the trans?....... i ran it and drove for a good mile at fastest speed and the problem disappeared for the next few times trying it out...... im going to try and do a bit of research into what may be causing this, but would really appreciate some input...... Share this post Link to post Share on other sites
squonk 41,444 #2 Posted September 2, 2012 Sounds like something is hanging up. Try starting it up and just try using the lift first. If the lift is erratic I'd say it's in the pump. Has the oil and filter been changed? This is why I got 2 parts tractors with hydro's in them. These sundstrands seem to be getting tired all over. If you want to test the trans in the shop jack it up and hook a belt on the pulley and run it off another tractor. Share this post Link to post Share on other sites
Martin 2,133 #3 Posted September 2, 2012 new oil and oem filter when i first got it a month or so ago. lift wont move at all until the trans/pump goes through its tantrum first. the trans has some drive noise but other than this problem when first 'waking it up from sleep' i am happy with its performance. drives as nice and as responsive as the other two i have, both of them are earlier sundstrands than this one though..... ive had good luck with them so far, until this problem...... Share this post Link to post Share on other sites
Callen 64 #4 Posted September 2, 2012 Do you have any leaks in the lift system? Will it push easy with the Tow valve closed? Share this post Link to post Share on other sites
smoreau 658 #5 Posted September 2, 2012 Martin, Sounds like its getting air in the pump or draining down. Did you use dextron or 10w30 motor oil. I see its a 76 so it should be 10w30 motor oil. Callen said, do you have any leaks? I know on the eatons, they take a few min before they will lift the implement. It may be a sign that its starting to go south I have a 74 c160 and it is the same way as yours, after it gets rid of the first jerk, its fine tell it sits to cool off. It has a leaking lift cylinder and I thought that might be the issue for getting air in the system. At least that's what I am hooping Its a sweet running rusty gem that I would like to clean up to make it look good again soon. So lets see if some one knows more then us can shed some light on this issue. :) Share this post Link to post Share on other sites
Martin 2,133 #6 Posted September 2, 2012 I noticed one or two drops from the cylinder over the course of at least 2-3 hours of running it on and off yesterday. This included the mile long run as well. I would think it would need a bunch more loss to cause it to be totally out of pressure for the delay it's causing. Sometimes it's up to 5 seconds or so. Running it till it got real warm stopped the problem happening . That's why I'm leaning toward the pump and something inside not being right. I'm far from an expert though, and will look at any suggestions you guys might have....... Share this post Link to post Share on other sites
Martin 2,133 #7 Posted September 2, 2012 Scott, it's got 10w-30 motor oil in it. I park this thing where I can see if it's leaking and there's nothing anywhere from the trans. In fact it's totally dry everywhere . The lift cylinder/ Hyd system is like I said in previous post, I seen one time it left a drop or two on the concrete. Maybe that's all it needs to cause air to get in? I will look closer at the cylinder. Especially the top fittings. Share this post Link to post Share on other sites
Trouty56 567 #8 Posted September 2, 2012 Mine leaks at the cylinder and causes no problems. If you only get a couple drops then don't worry...be happy.....at least about the cylinder. Might have something to do with the charge pump. Wish you luck. Share this post Link to post Share on other sites
JackC 617 #9 Posted September 7, 2012 On the older machines, I believe the oil level in the pump is checked with the pump running. If it is checked when the pump is not running you may not have sufficient oil in the system. There was a service bulletin on the issue and the dip sticks were later changed. Check it both ways and be sure the oil level is at least at the full mark for both cases. Share this post Link to post Share on other sites
Martin 2,133 #10 Posted September 7, 2012 jack, i looked into this by searching the service bulletins i have. the only reference to what you have mentioned concerned the eaton transmission in the c series and not the sundstrand. it would be worth a look though to see if it makes any difference with the problem. ive been doing a little research and i think it maybe an acceleration valve issue, but im still looking into it. the bulletin concerning the cold oil level is below... WH61-90 #366 Eaton Transmission Oil Level.pdf thanks for your input.... 1 Share this post Link to post Share on other sites
JackC 617 #11 Posted September 7, 2012 Martin, that is the bulletin I was thinking of. See the recent thread on hydro gear springs (link below). Sounds like the springs can break . There are springs in the check valves and acceleration valves that can go bad. I have a 1975 C-160 that is very weak in reverse. The sundstrand manual points to the reverse check valve but I have not taken it out to look at it it yet. I did get a 3/8s drag link bit so that I can remove the valve for inspection. If the acceleration valves are not working properly that could explain what you are experiencing. 1 Share this post Link to post Share on other sites
Martin 2,133 #12 Posted September 7, 2012 jack, yes i seen that thread the other day. thanks.... just as an experiment, i went out after my last post here and messed around with the levels. i even checked the dipstick level against the sundstrand in the 875. the c160 dipstick is short and is hard to get to and i always wondered if it wasnt correct for this tractor. the levels are exactly the same as the old square plug dipstick on the 875. i didnt check it against the 1277, but i think that both the 875 and 1277 are the same so i didnt bother. anyway the levels are all the same, should be slightly above the axle tubes (rough description)... on your c160 what does your dipstick look like? is it short enough that you cant reach it through the dipstick access hole in the seat pan? looks like the dipstick on mine should be for the tilt up seat pan instead of the fixed. maybe the 75 has the tilt up. mine is a 76 and is fixed with the seat only tilting up on the fixed seat pan. maybe they carried the short dipstick over for a bit onto the 76 setup... anyway i topped up the level a little to get it dead on full. running or stopped the level stays the same on mine....... it didnt make any difference to my problem. the thorough warm up the other day seems to be the only way i could stop the problem..(only happened once though) like you, at the moment i am leaning towards valves (sticky not broken springs) as being the culprit for my problems... theres an orifice in the accel valve that i need to look at too..... i dont want to tear into this one yet as i have another tractor for my son to start on, so it will wait until i have some spare time...... 1 Share this post Link to post Share on other sites
Agage1 83 #13 Posted September 8, 2012 Martin I'm having the same problem with one of my c160's. My dipstick is short and hard to get to, I thought it may not be original as well. I think the problem in my tractor may be be a little further along than yours. It started having the exact same symptoms as yours. Now after I start it up I have to use my weight in the seat to rock the tractor back and forth to get it to move. After this it usually runs fine. But when I put the dozer blade on and it digs in a little the tractor will sometimes lock up and I can't get it to move unless I violently rock it back and forth while holding the lever in forward or reverse. Let me know what you find out about yours I'd really hate to put my spare tranny in I'm trying to save it as long as I can. Share this post Link to post Share on other sites
WheelHorseSteve 56 #14 Posted September 8, 2012 Sounds like exactly what happened with my c-160. The pause... The non functioning lift... Then a violent surge forward. It started around a 1-2 second pause and got worse... To the point where it wouldn't move at all. I have that tranny sitting around... Would love to open it someday and fix. Will be watching this thread closely! Share this post Link to post Share on other sites
smoreau 658 #15 Posted September 8, 2012 After thinking about this for a while, I think it may not be the pump. But the drive motor the pump is bolted to draining back. I have never taken one of these apart. But if it drains back to the trans axle, it would make a violent lurch the first time you go to use it. I think the charge pump is in this end also. Share this post Link to post Share on other sites
JackC 617 #16 Posted September 11, 2012 Martin, my 1975 has the tilt back seat. The stick is very easy to get to. The stick itself is only 51/2 inches long. Share this post Link to post Share on other sites
Martin 2,133 #17 Posted September 12, 2012 that looks like the same dipstick length as mine jack. i dont have the toolbox etc just a bracket that sits on the top of the trans that the seat pan bolts to.. makes it a little challenging to reach through the hole in the seat pan, much easier to get it from underneath.... Share this post Link to post Share on other sites
SousaKerry 502 #18 Posted September 12, 2012 I wonder what would happen if you ran some of that Seafoam for transmissions and hydraulic systems through it to clean out the insides a bit? Share this post Link to post Share on other sites
JackC 617 #19 Posted September 12, 2012 Good question. Has anyone tried the SeaFoam Trans Tune product? Sounds like it could clean things up and maybe make some sticky check valves work better? http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_trans-tune-transmission-treatment-(16-oz-)-sea-foam_7120021-p#fragment-3 Share this post Link to post Share on other sites
Martin 2,133 #20 Posted March 8, 2013 im bumping this one again. im spending a little time on the c160 at the moment, rebuilt/welded a new inlet on the oem muffler, rebuilt the leaking carb and got it running sweet...... now i want to mess with the trans. nothing has changed, symptoms are still exactly the same. just wanted to throw it back out there for any ideas from the hydro wizards...... Share this post Link to post Share on other sites
chrisd200(inactive) 55 #21 Posted March 9, 2013 My D200 (sunstrand hydro) was having nearly the same symptoms. Start the engine, move motion control lever.... and nothing. Wait a few seconds or gently rock the tractor and BAM...... sudden jerk in either direction. Reverse was weak but forward was a little sluggish as well. The three point hitch was also weak and would not work at first start up either. Once you got everything working the tractor would function but just didn't feel right. If you turned the tractor off and let it sit for a minute or so you would have to go thru all of this again. Pressure test were inconsistent. I removed the pump and had it rebuilt by a professional hydro. shop. Installed pump........ same problem I was advised to check and see if there was anything that i could find wrong with the drive motor. I was doubtful, but removed it anyways. When I pulled it away from the rear end I noticed that the inlet screen was plugged with silicone (assuming from where previous owner had the rear end worked on) and some sludge. I cleaned the screen, re-installed the drive motor and the tractor has been working perfectly for about 3 years now I guess the whole system was simply starving for oil to the point it just couldn't "GO" at first but was getting just enough oil flow to slowly get things moving. Don't know if the hydro "C's" are the same as my "D" but i thought I would mention this. Hope it is of some help. Share this post Link to post Share on other sites
coldone 35 #22 Posted March 9, 2013 the hyd lift is non responsive. once we have movement hyd lift works normal, tractor drives normal, speed of travel is dependent on amount of movement of dcl ( The C series sundstrand is exactly the same as the D series. Only differences are in the motion control linkages and the pulley input. The lift comes straight off the charge pump, which gets the oil straight from the transaxle. Sounds like you are loosing prime to the charge pump. I think you are going to have to pull the hydro unit and see whats happening. There was a thread about this same problem and I believe it was a D series, but I cant remember if it got fixed or not. I want to say its something simple internal to the pump, like its a slipped snap ring. Share this post Link to post Share on other sites
MalMac 1,331 #23 Posted March 9, 2013 I had a C-120 years ago that did the same thing. Finale one day while sitting in the seat rocking it back and fourth with no luck I returned the motion control back to neutral and got off the tractor. Started double checking the control levers to make sure everything was like it should be, this was with the tractor running. I turned my back toward my tool box and then it happened. I heard the sound of tire chirp and away it went. The tractor had taken off all on it's own. Stayed going straight as an arrow down the drive about 100ft. Crossed the hi-way that was in front of are farm then down into a 12ft deep drainage ditch. Amazing how fast one can go when your a short fat guy such as myself trying to chase it. It had got a pretty good head start when I caught up with it, I had to wait for traffic to cross the road. By that time she was nose down stuck on some kind of a tree. So Warning just because the lever says it's in neutral, what ever was wrong inside that tranny said GO! be careful. 1 Share this post Link to post Share on other sites
Martin 2,133 #24 Posted March 9, 2013 Yes, that has happened to me as well, but I was on the tractor. Thankfully I stopped it before it really got going. I just don't ever get off this one with it running, I just don't trust it........ Did you have the transmission park/ belt disengaging active? Would never get off it without activating that first, whether the trans is working good or not...... Sent from my iPhone using Tapatalk Share this post Link to post Share on other sites
chrisd200(inactive) 55 #25 Posted March 9, 2013 yeah the big D did that once and plowed into the back of a parked F100. Not Cool Share this post Link to post Share on other sites
