1466 low lube pressure.

[fordfx413]

I have a 1466 with 5-7 psi of Lube pressure at mid to high idle, around 1-2 psi at low idle. Once the oil warms up the tel lite will come on. New hy-tran and filter. If
i hold the T/A lever in the middle position, lube will increase a couple PSI. I capped off clutch booster, seat valve and brake valve, same pressure readings. I pulled
the valve squirted a little oil in the top lube port and oil pours out of the T/A bearing. Blew some light air pressure in the top lube port and there is zero resistance.
(Yes I was under 15 psi of shop air pressure). Question, is the brass baffle in the T/A the problem? Is it supposed to hold pressure or is there supposed to be free flow
like i have? The MC pump seems weak, was going to replace and go through the valve, but not sure how much good it will do with my lube problem. Regulated pressure was
around 250 PSI in T/A and DD. Thanks.

 

[caterpillar guy]

First you need the filter changed then a flow meter to check if you have the appropriate flow and pressure. One could be fashioned with a hose and valve with a pressure gage you would also need some extra oil so you don't run out in the transmission and ruin things. Then some pails to collect the oil in as it flows through your home made meter.

 

[rustred]

he said its a new filter and oil. but anyhow my 806 is doing the same thing. i have been running for 2 days at 6-7 lbs psi. sure is funny nobody can put their finger on the problem. i see others with this same problem and no answer. there has to be something going on whn it gets hot. plus that IT manual is useless. i checked steering pressure also hot and goes to around 1500 psi deadheaded. i am running with 3 gauges hooked up. with torque in centre it goes up a bit, shift to t. a. and its slightly higher than the 6-7 lbs in direct, about 8-9 lbs. its running 190 psi hot. plus i would like to know what is this lube pressure is lubing? or what is its purpose? i have no idea other than everyone saying lube pressure.

 

[caterpillar guy]

Lube pressure is oiling the gears and if a TA delete then the ring and pinion oil flows through the hollow pinion shaft to the pinion bearing to give it pressure oil. As for the low pressure I suppose it could also be the o-rings around the tubes going to feed the TA through the side of the case when you remove the MCV. You will find 3 tubes flush with the case they each have an o-ring on them. Since I don't have any TA tractors around I can't tell you how they come out. That would both let the lube pressure drop and the TA pressure.

 

[pete 23]

GSS 1333-2 is the book you need . It goes into great detail on the mcv system, much better than any other manual.

What the lube circuit does. It used the oil in regulated system that is left over after actuating the TA clutches and the one gal per minutes always going through the brake valve.

The TA clutches are dead headed so only oil used after they are engaged is from leakage which may occur at the several different places in TA circuit.

Under ideal conditions there will be almost zero oil losses in TA clutch circuit.

That remaining oil now goes to lube regulator valve. It sends oil to the inner workings of the TA bearings etc. Ideally only one gallon per minute should be used in ta from lube circuit.

The remainder of the oil in lube circuit then goes to the transmission and pinion bearing lube.

So, you see, running low lube pressure may not leave any oil to transmisson although TA would still be getting some lube.

Checking regulated pressure with TA lever in middle position is critical as that can tell you if the ta is losing the oil or lube circuit in ta is losing oil. There should be a 15 psi lower pressure in regulated circuit if normal.

If sump check valve is leaking, you will not have enough oil to do all the jobs even if TA is perfect. Therefore, following test results and interpeting them is everything in finding the problem

Some times it is even necessary to pull MCV and block the tubes to find which one is leaking. Especially the lube circuit. Sump valve can be blocked easily also if suspect. Air pressure used properly will easily show a leak at sump check. Not as easy on TA circuits and VERY Carefully, test lube circuit with air at no more than 30 psi or you will blow the lube baffle and now do have a leak.

Reason no one gives a definite answer is because there are just way too many things that will show low lube pressure.

OH, also pressing on brake pedal will block the flow to brakes to help find problem. (AND here , note, 806 feeds l gallon per minute to brakes always, later models only use that l gal when brakes are used so a difference in brake valves was made to provide more regulated flow for other jobs.

 

[rustred]

thanks pete. where do i buy that book? it is puzzling why it takes an hr. for pressure to drop down to the 5-7 lbs.

 

[pete 23]

Some one else may know better place to buy a book but E-bay may have one. Binder books, Jensales for a couple ideas.

Taking that long to lose pressure would indicate smaller rather than large leak.

 

[the tractor vet]

Well since your pressures are ALL down across the board I would wstarrt with checking the pressure regulator springs for length and spring pressure at length as i think you will find that they will come up short . NOW IF the pump is good and the T/A is NOT getting wore out and it has NOT developed excessive end play and leaking internally . Your running low on loc up pressure at 190 Hot and should be around 230 , i like to set them around 245 HOT on tractors running up to 125 Hp and o the ones that have there tails twisted like the 1066 we have it is and has been running 280 for the last 27 years . Over time the springs in a MCV get hammered into submission and they may seam to work ok but they are NOT really getting it done . You have and inner and outer spring in the pressure reg. valve . When you install a new spring kit you have to make adjustments to the inner spring by cutting off one coil per 10 PSI drop needed . Also check you oil temp and see just how warm it is getting . Working norm is between 160-190 working hard . all pressure setting should be checked on operating oil temps . Same when your working on setting PTO loc up pressure . When i do a T/A job i get a little over the top on OCD because i do not like jobs coming back and have to work on my dime .