Do Tractor Hydraulics get Weaker When Warmed Up

[dieselscout80]

Do Tractor hydraulics get weaker the tractor is warm?

My IH 424 when first started lifts my Alamo SHD96 flail mower just fine, but after just a bit of running it will no longer lift it as high and it takes more engine RPMs to lift it.

The Alamo SHD96 flail mower weighs 1170lbs and the 424 family of tractors (e.g., 354, 364, 384 and 444) seem to be rated to lift 2600lbs.

I changed the hydraulic fluid, filter and (should have said cleaned) suction screen to see that helped, but still acts the same. I just run generic hydraulic fluid from TSC.

 

[shovelmike]

If your hydraulic system is in good shape you should not lose lifting power when warm. It is likely that you have some internal leakage in the system, such as the seals on the lift cylinder. The cold fluid is thicker, it loses some viscosity at higher temperature, thus can get past worn seals more easily.

 

[dieselscout80]

If your hydraulic system is in good shape you should not lose lifting power when warm. It is likely that you have some internal leakage in the system, such as the seals on the lift cylinder. The cold fluid is thicker, it loses some viscosity at higher temperature, thus can get past worn seals more easily.

Kinda what I am thinking too it is a +50 year old tractor...... after all I don't work as well as I once did

 

[Thomas]

Is there screen in the line might slowly clog performance ?

 

[dieselscout80]

Is there screen in the line might slowly clog performance ?

Yes, two and they have been cleaned see my 1st post.

I think if it was that it would always act the same cool or warm.

 

[oldnslo]

Could also be pump getting worn after 50 years. To determine exact cause would require performing mulitiple tests to eliminate or identify the cause or causes.

first one would be simple pressure test

 

[BukitCase]

Simpler than that - put a fairly heavy implement on the hitch, raise it up, shut off the tractor. I have two older tractors; the Allis doing that test the implement will hit the ground in about a MINUTE; the Long: stays up all night (probably the ONLY thing that's not wrong with it :=)

Guess which one's on my list of "shoulda done thats" ... Steve

 

[dieselscout80]

It can keep the flail up in the air when shut off.

I replaced the pump about 5 or 6 years ago.

 

[oldnslo]

If flail stays up them seals on rock shaft cylinder are good

potentially another leak path in 3PH valve assembly possibly O-ring leaking on some interface. Had that on our 5000 Ford where O-ring between main transmission housing and valve stack failed allowing oil to leak back into the transmission.

 

[Sonny580]

pump should still be good ---- I would say valve body wear beyond specs. Pressure test would be in order to check everything.