Does anyone know what the trans oil level in the filter housing just foward and below the charge pump should be when not running? I can't seem to get the charge pump to bleed. It just stopped shifting and we thought it maybe got some air from somewhere but the trans oil level was low, it needs to be way high on the stick to worknormally. So when I open the filter housing to check for clutch material I noticed that there was about an inch of oil in the bottom of the 90 that is connected to hose and tank and this is with 2 inchs over on the trans dipstick. is this normal or possible restriction somewhere and the machine is fairly level. Need some help on this one.
normally that filter is full when changing filter. could be a restriction in suction line. have to drain oil, pull suction hose from tank, then remove suction screen. check for cracked suction hose and bad o-rings indicating a suction leak. if pump is weak will not pull oil up out of case when oil is low. if it isnt any of these then your pump is out. #7 is where your suction strainer is. if this is the right serial number for your machine. if not give us you P.I.N.
John, Working on level ground the oil level at full on the dipstick running, should be okay. Follow the diagram and check the suction screen, clean it out. There should also be a screen in the rear under the trans mounting flange, check it too. Change the filter and cut it open. If you find much metal and debris you are into a trans repair including Torque and exch cooler. Plus wash out the flywheel and back housings and all lines. If everything is clean then take the pump off and inspect it. I have seen some have gears break up and ruin a pump. Come on back and we will talk more. Later Bob
thanks guys i was afraid of that, guess i'm pulling pans to get in there.
oh and the serial number is 8220
Well this morning trying to get the 7 off the hill I pulled magnetic filter out and still only 1 inch or so of oil in the bottom so I poured about 22 gallons in the housing and all of it disappeared the level come up about an inch or so and the level on dipstick come up??? what the hell does this mean? why would the oil equalize in only one direction? wheres the oil going? How much oil does the system hold? very confused. and one more question what does hose from charge pump housing side do? also the engine, trans, and torque were overhauled and hasn't had many hours since so trans and should be ok
I seen the case cracked before where main frame welds to it. Oill fills up in main frame and leaks slowly near the front. That sump holds alot of oil though. I could look it up in a little bit but if it leaked out most oil slowly from say trans yoke and you are just trying to top it off.....22 gallons will only be half way there. I think a d6h carries 28 to 32 gallons but that is a bigger machine. if no visible signs of leaks anywhere....keep putting oil in it!
didn't see any leaks and dipstick says overfull already and it stopped shifting suddenly so didn't think leak
only place it can go is out to the ground. there is a cooler in radiator but not much oil getting in there. can push into rear engine oil seal but 22 gallons would have already way over flooded engine. had to leak out my good sir.
So John, what did you find in the mag screen and filter?? Later Bob
nothing in the filter bob, and found no problem with suction line so today i will replace suction line and all o-rings and if that don't do it? I talked to a guy over phone yesterday that told me to fill the gear pump with oil and if it primes right away then usually air leak, so thats what I did and it went into gear as soon as I released the air from top of pump. I'll let you know what I find today. Also he told me that mag filter housing is normally empty and he was working on these things when they were new as a cat mechanic. Oh and what part of Ontario are you from bob I'm in Fort Frances
Down Hwy11 north of Toronto. Check pump pressure at high and low idle, should hold 90% at low idle. A worn pump could lose it's prime. Later Bob
Well I should have suction hose and orings today so I will test pressure if I get it bled. I read somewhere that gear pump pressure should be 150-175psi is this correct? I hope this does it because that hose wasn't cheap and I hate diagnosing with new parts, gets expensive.
John, the pump pressure P1 on back cover should be around 400 Psi P2 is 55 Psi less than P1. Torque converter inlet relief is around 120/130 Psi, converter outlet relief is around 60 Psi. Later Bob
Well I changed everything from the rearend to the gear pump and no change. I would assume that if this pump makes 90% of its pressure at idle I should have no trouble bleeding it at idle, or am I wrong? Had it near WFO snd it still wouldn't prime, it would blow air-oil mix out with quite alot of oil but as soon as I close valve it would lose it's prime. The oil is 2 inches above full on the stick but that will go down as soon as oil starts to move. When the machine stopped shifting it was working good then just wouldn't go back into gear doesn't really sound like weak oil pump. does anyone have any experience with these pumps failing? The serial #94N8220 also can't see diagram provided that well does anyone have somthing larger or clearer with the legend, there must be screen or somthing blocked.
94N8220 is a 1974 D7F with 3306 engine. I can post parts diagrams but I don't have the schematic and test pressures. Latest I have is for the D7E. Bob/Ont, is the 7E the same?
yes I think labeled diagrams may help, would like to be sure theres no clogged screen or something else before the pump gets pulled. Is there some sort of procedure for priming this charge pump? Maybe I'm doing something wrong.
Here are the lines and pump. Pump may be shot or seal #17 is leaking, also check any other o-rings and seals on the suction side.. As long as there is some oil in the pump it should take suction. Based on the diagram it looks like you can't get the suction level any higher than sump level. Could at least put some in through the test port plug, just don't want to run it dry.
John, disreguard all I have written. You have a D7F not a D7H. You have either got a big suction leak or a worn out pump. Since it happened fast I think the suction line is the problem. Look for any place another line is rubbing the suction line, steel lines can wear through and the wearing hose seal the oil in. Pump might pick up air but oil not leak unless you pry the lines apart. Later Bob
Ya the diagram confused me a little looking for a screen, I have already changed the suction line and all orings that could be changed. So looks like pump or seal, should find out today and let you's know.
Well I think I gotter figured out. I pulled gear pump out and apart and found the seal #17 on spline shaft was in 2 pieces and both of the large orings #10 had shrunk and split apart 3/4" but I think it was #17 that done it. None of the surfaces looked scored so its getting new bearings and seals hopefully tomorrow, is there any trick to changing the bearings?
John, if you could borrow a large fine thread tap that would cut threads in the bushings. Tap them and when the tap bottoms out it should push the bushings out of the blind holes. Make sure not to dammage the bores or the bushings will bind on the shafts. The broken lip seal would allow the pump to draw air and not pick up oil. The suction is drilled to behind the seal to keep oil from building pressure there. Later Bob
Well fellas that did it, the pump bled easily and away it went. Hopefully wont have no trouble with it for a while since near everything was changed. Be happy to answer any questions, and thanks to all for the pics and help.
Your welcome John, but please give serial# not D7? letter. Keep on pushing them rocks and Christmas trees up there. Later Bob