3020 powershift

SVcummins

Well-known Member
I have a pressure question about my powershift oil pressure when I?m running my remote with jumper hose to warm up the tractor the pressure drops on the needle to the low side of the gauge as quick as I put the remote lever into neutral the psi Jumps up past the minimum line . Is this ok or should I turn up the pressure on the pump
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I would say that your main pump is sucking all of the oil that the transmission pump is pushing out, after all your just dumping the return oil back into the case. My question is that if the heater hose in activated and dumping oil back into the case, do you still have enough pressure / volume to shift and drive the powershift?

If you are running lower pressure (as your gage says) while your dumping oil back into the case I would assume you will run a good chance of slipping the clutch plates and warping them.

I would not be driving the tractor with the heater hose dumping oil back into the case.
 

As previously stated. The transmission pump is not keeping up with the front pump.
Transmission filter and screen condition ?
Does the scv return to the transmission case or into the return line that joins with the passage between the transmission oil pump outlet and the oil filter inlet.
How about a throttle valve in the line ?
 
Shifts fine and works fine but I?m worried about the
trans pressure both filters are new and changed the
oil last fall . Have not checked the screen yet the
oil was in horrible condition I changed the filters
once then changed the oil after running for about 50
hours and changed the filter again .
 
Filters and oil are both new . I have not checked the
screen . The hose is just a jumper beteeen outlets
on the scv .
 
So i went out and did some more testing I wasn't sure where to take temperature reading so I idled up the engine to about 2200 rpm cycled the lever for the outlet with the jumper hose I took temperature reading after about 20 minutes with my infared thermometer right at the hose tip the temp was 122 degrees I left that scv running then cycled the 3 point up worth the blade attached and the other scv with the angle cylinder for the blade plugged in cyling all 3 circuts at the same time over and over and even steering the hoses or operation of any circuit never was jumpy or eratic
 
According to the service manual the powershift trans pump pressure should be checked at 2100 rpm with all hydraulic levers in neutral
 
The gauge on an early series powershift is lube pressure.
Industrial models like 770A grader and many crawlers had 2 gauges, one for lube pressure and the other for trans pressure. You need to get a trans pressure gauge from letìs say a 450 crawler, they are cheap aftermarket ones.
They will tell you if transmission is safe to operate. I will be doing that mod when I will be fixing up / restore my Powershifts.
 
I think when it warms up I will plumb a pressure
gauge in like the service manual shows and see
how that test goes
 

Does this tractor have dual scv's? If so have you tried installing jumper hose in other SCV to see if gauge registers any different when control lever is activated?
 
Don't trust the dash gauge. Tap into the pressure control valve with a known good gauge. I don't think the transmission pump is keeping up with full volume flow that you are putting through the jumper hose. I think this is normal and that is why these tractors have the extra reservoir of oil in the cooler up front. The idea was to supply oil for the short burst of full flow not the extended run. What does the service manual say about how to do the transmission pressure test?
 
Yes it does have dual scv . and the gauge drops all though not as far when I cycle the lever for the other
outlet with the scraper angle cylinder attached .
 
Well I submitted the question to the mr thinker department . Guess we will see what happens . Only other thing I can see to do is run it and watch it I guess
 
Ill have to read the procedure again but the thing that stuck out was the fact it says to have all hydraulic levers in neutral so maybe I'm all right ? Transmission does not slip under heavy load I can kill the engine . I just got to watching that guage and I started wondering ?
 
(quoted from post at 23:10:12 03/06/18) Ill have to read the procedure again but the thing that stuck out was the fact it says to have all hydraulic levers in neutral so maybe I'm all right ? Transmission does not slip under heavy load I can kill the engine . I just got to watching that guage and I started wondering ?

As previously stated, the dash gauges can not be trusted.
 
I have the service manual an i&t and the John
Deere . I had the manual for the hydraulic pumps on
these tractors but it?s gone
 
(quoted from post at 01:35:59 03/08/18) I have the service manual an i&t and the John
Deere . I had the manual for the hydraulic pumps on
these tractors but it?s gone

The I&T manual contains just enough info to get people into trouble .
 
I like the i&t manual I usually read the john Deere manual combined with it and cross the information I
like having things explained 2 ways. Most of the information is exactly like the Deere manual just written
differently the i&t has no info on seats or wheels or very much info on the electrical systems
 

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