806 pictures

nothing wrong here after working 8 hrs. clean as can be.
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here is pressures after gauge hook up. 20 psi at dump valve. 200 on pump. after working for about 1/2 hr gauge drops to 8 psi when oil gets
hot.
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i set the valve according to the gauge and this is a piece of cake. i sure dont know why ih does not have a manual gauge in the dash as thats the answer. i do plan on installing both gauges better but at least for now i know all that TA lever is good for is to hold the gauges. i may be a novice at this tractor but not over my head or a dummy either. i have hydraulic experience. with that filter as clean as new after 8 hrs. i hardly believe i have a big problem. i sure did not slip any clutches as implyed. i give a person heck when they are sitting holding the clutch down or slipping one. but anyhow as i said before my problems start after oil is hot. and with these gauges i see whats going on. not some goofy light to go by. it will not be hooked back up either unless i tee it into that line. i asked abut a crack in valve body and got no reply. i asked why is pressure dropping to almost zero when steering cyl. is bottomed out each direction, dont think that is normal. got no reply. i always try to get enough info so someone might have the aahh haa moment. not telling me the sprag is gone or clutches are burnt. its something to do with loosing pressure here. just asking for ideas as u experts that worked on piles of these must have seen some odd ball stuff. and no i dont expect a miracle cure as i want to find the problem and i dont give up on stuff. i do know i need a service manual but i can still figure stuff out with some little pointers. and also the clutches require pressure to operate so need pressure fixed first. and with the oil hot and low pressure that is why tractor waits or wont move. i am going to reseal the mcv valve next. as i said also this tractor sat 45 years and o rings dry out. i have not seen the inside of one of these tractors either, but nothing i wont tackle.

If at any point in its operation, the foot clutch is all the way up (foot off) and the tractor jerks into motion, or doesn't move , then does, the one way clutch is to blame. If the one way clutch fails, or is intermittent, the rear hydraulic holding clutch is slipping. If the tractor (noe drives in direct until the oil is warm, the front TA hydraulic clutch may be hemorrhaging and loosing MCV pressure. The worst that can happen is front clutch failure to the point that it will not move (and that is because the One way is not holding. Jim

Ok so you are showing around 19 PSI on the Lube circuit , and around 200 on lock up pressure and then your down of almost o . Now this is all well and good up to a point what are you reading when in the high side and the low side ?? And here is where your lacking the one reading that you can not do because you do not have a test spool that goes into and replaces one valve and you add in one more gauge . Now here is what YOU should have for lock up pressure if she was all ORG you would have about 215 on both high and low , I set 706 gassers at 235 and diesels up ten more and turned up tractors are set a 275-285 and around high pressure or 2000 -2200 , lube circuit 25 . I have never seen a MCV crack , i have seen them Blowen off the side of the tractor when someone trys to jack the pressure out of sight but never cracked . Low pressure when warm can be a weak MCV pump or weak springs in the pressure regulator valve , blowen o/ring or MCV gskt , bent baffle in the T/A blowen seal in the t/A clutch pac. . This can be checked with the removal of the MCV and doing and air pressure test on the clutch pac thru the tubes behind the MCV . at what temp of the oil does the pressure start to fall off ?? The more i see and hear it is coming down to a T/A job and a rebuild of the MCV with a new pump . along with that your going to need a New IDPTO input shaft a clutch and pressure plate and three bearing one for the IDPTO shaft and pilot and throw out bearings . Then once you get into the speed transmission it is anybodys guess , Some ya need nothing and others ya just start writing down part numbers . My 1486 was one of those , both shafts and all the gears and bearing . You mentioned that she would stop moving when warmed up well yep with a presure drop to the clutch pacs she will and you said she would set there then Bam she would hit and go . That is a classic sprag failure . As they will stop dead in there tracks and with out warning IF you don't shove the clutch down they will and do the kerbam and off to the races . When i test a tractor for a bad T/A i have found that alot of times the T;/A seams to work just fine in the bottom 4-6 gears , what i mean here is they will grab almost every time in 1-4 low range and 1-2 high range BUT when you stuff them up into 3-4 high wind her out and start dragging it down on the brakes then pull the T/A into low side be ready to kiss the steering wheel or the glass if it has a cab and have your foot on the clutch if is does stop . Here is something to try , Pull the pressure regulator spring and lightly stretch it maybe like .025 at a time di the inner spring not the outter and see how much the pressure comes up. That lies under the top plug on the back or rear of the MCV . I is under spring pressure so be ready for flying pieces , Next pull the flow divider valve and see if it is floating free in the bore.that is the one below the sending unit .

Oh yeaone more thing here , your spool valve make sure that when in the high side or lever ahead that the spool valve is all the way down sdo the little snap ring is flat against the valve NUT

ON the pressures dropping or light coming on when steering to stop, that would be a high pressure problem that is normally a weak pump. But it can be other things that cause oil to escape like leaking o-ring or gasket in mcv.

The older mcv pumps used to blow the diaphragm a lot and I repaired a lot of them years ago. Now days that would most likely not be an option due to parts available.

Normal test of pressures with the two gauges hooked like you have them, you test in direct drive, in TA and then also in the middle position of TA lever. Middle position normally will show a 15 psi drop in the regulated pressure due to a different path oil is taking, and lube pressure may increase some because no oil is being supplied to the TA clutches, either side.

Turning steering to lock and holding will show a drop in regulated and lube pressure if pump is bad or like I said, any high pressure leak . A good pump and system will normally show just a few psi increase in the regulated pressure at steering to stop just because the steering relief valve is now popping off right where that gauge is hooked up.

On the low side of TA the one way sprague (over running clutch does the actual pulling, so even if you had the mcv pump on the bench the tractor will still pull it's self if sprague is good. The hydraulic part of the low side is to prevent free wheeling but will pull tractor under no load and if you saw those little pistons that apply the pressure to that free wheeling clutch you will readily see why they can't pull much load.

I'm sure you already knew a great deal of this information but thought I would just throw this out to you. And that filter looks just fine for 8 hours use.

thanks pete, vet and jim! that steering deal was throwing me off as i figured it should be building pressure not loosing pressure going over relief. i kinda was thinking weak pump but not sure . and yes the snap ring is down as i checked that operation. i did no checking with TA in low cause i saw pressure dropping as working so left good enough alone. but anyhow i bought this unit as a non running tractor. rear tires where flat. engine was lightly stuck. i thought this was a good project for me as the price was right. and i thought it was in not all that bad of shape for a 10 year use tractor. they said parked in 75.
the same deal with my 660 i found it in a guys cow pasture in saskatchewan be 12 years ago now. it was stuck had sheet metal missing. i payed the guy 200.00 as thats what he wanted. i went threw it and did what it needed to get it usable . did nothing with torque though i dont need that. rebuilt the head. replaced that 2 times due to a crack on first one now head gasket is iffy. dam felpro junk was looking at a used one i had in shop today also that i replaced on a friends tractor. but this 660 i have good luck basically for 12 years and even take it to the antique tractor pulls and it does very good. i have got first and second place with it. its just my hobby to get an old tractor and then put it to use. get the satisfaction of using something somone else gave up on. how else is a person to learn stuff. this 806 will be project now for later on as i am getting busy for harvest. now i know what i am looking at for repair. and they actually grow on you after working it. one bad thing your sitting up high in the wind not like the 660 as you have more protection around you. also has more power bit burns more fuel too. lol. ooh and i burnt the tank of 45 year old diesel in it also.i did change fuel filters though. fuel looked good and clean so burn it out. could not tell old fuel from new fuel. i did add conditioner to the old stuff. and she does use oil but that might smarten up later hard to say. i am second owner now.

Where do you get a gauge like that one??

(quoted from post at 11:26:17 09/04/20) Where do you get a gauge like that one??

Click to expand...

Amazon, where else.

i have a bunch of these old ones on hand from work and also old hoses. sure come in handy for this job. we rebuild units down to the bare bones and they get all new plumbing and guages. they are about double the weight of this tractor and lots of plumbing hoses. makes this tractor look simple. but yes with out cranes and equipment this will be a challenge for that reason. the electric motor on it is about 2 tons. napa or any jobber has these gylcerin filled guages, over 20.00 i think. the standard guage has to much fluctuation. i even tryed one and the needle was jumping all over.

I stopped at O'Reilly's to see if they had thm or could get them but guy could not find one so he is suppose to call me latter today

Well the guy from O'Reilly's called and he found a gauge like your but it costs $60 so I figure I'll keep looking

Surplus center has those gauges for about 10$

I'll have to look in there catalog here in a bit I didn't even think to look at them

Yesir they have a bunch . My local fiat cnh dealer carries them under the ag smart line

With shipping it is going to cot me $20.05 sure a heck of a lot better then $60

Thats a pretty good deal