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Topic: Hydraulic Tank Question (Read 594 times) previous topic - next topic

Hydraulic Tank Question

I've noticed that I have hydraulic fluid around the outside of my tank, and I think its coming from the dipstick/fill opening.  The cap does not screw down, so I'm assuming that the fluid leaks out from there.  My question is, is this tank not suppose to be pressurized? 

I was trying to check the RMP's of the radiator fans, and at approx 1700 RPMs the blades were spinning around 350 rpms, which seems low, from what info I could find. 

This is on a 97 U295 with the Cummins 8.3

Re: Hydraulic Tank Question

Reply #1 –
Quote from: Brucep86 –
1.  The cap does not screw down,
2. so I'm assuming that the fluid leaks out from there. 
3. My question is, is this tank not suppose to be pressurized? 

Bruce,
1. It should, either the nut looking dipstick thig has stripped or it has came off and in the bottom of the tank
2. Could be here or the Oring for the tank top. Before you ask #999-55a gasket is what you look for
3. The tank shouldn't be pressurized

Mike

Re: Hydraulic Tank Question

Reply #2 –
Bruce,

As Mike said, the hydraulic reservoir is not pressurized.  Oil is pumped into the tank through the return line, and pumped out of the tank through the supply line going to your hydraulic pump.  The tank always stays at atmospheric pressure.

The dip stick is the thing with the "T" handle.  If it is working correctly, you turn the "T" handle clockwise to lock it into the hole in the top of the tank, and anti-clockwise to remove it.  You should have a similar type locking dip stick in your transmission oil filler tube.

If you can turn the "T" handle clockwise and it never tightens up, then like Mike said the nut (inside the tank cover) is either stripped or it fell off.  Either way, the solution is to remove the lid and see what is going on.  If the nut fell off, it will be in the bottom of the tank.  You can use a magnetic retrieval tool or a claw tool to fish it out.  DON'T remove the filters unless you are sure you know where the nut is.  You don't want the nut falling down inside one of the hydraulic lines.

If the dip stick won't tighten down, for whatever reason, pull it straight up and out.  Then check the oil level in the tank.  One reason for the fans turning too slow might be a very low oil level in the tank.

Let us know what you find.

Re: Hydraulic Tank Question

Reply #3 –
Quote from: Brucep86 –
I've noticed that I have hydraulic fluid around the outside of my tank, and I think its coming from the dipstick/fill opening.  The cap does not screw down, so I'm assuming that the fluid leaks out from there.  My question is, is this tank not suppose to be pressurized? 

This is on a 97 U295 with the Cummins 8.3


New dipstick: Amazon.com: Dorman - HD Solutions 917-5506 Engine Oil Dipstick : Automotive 
As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Hydraulic Tank Question

Reply #4 –
Quote from: Brucep86 –
I was trying to check the RMP's of the radiator fans, and at approx 1700 RPMs the blades were spinning around 350 rpms, which seems low, from what info I could find. 

This is on a 97 U295 with the Cummins 8.3


Temperature relative. Needs to be at temperature fully saturated before fans will fully ramp up to speed.

Re: Hydraulic Tank Question

Reply #5 –
Ok, thanks for the responses.  The dip stick appears to be intact, but it is tightened all the way.  I will loosen it and then see if I can screw it down.  I will also check the top seal on the tank.