Too much hyd fluid?

[bones1]

Can too much hydraulic fluid in the reservoir cause the boom cylinders to leak at the seals?This probably ranks right up there on my dumb question list but I wonder if it could over pressurize the cylinders to the point of leaking on a new machine.I check my hydraulic fluid every time I use the tractor because both boom cylinders are leaking since I bought it,29 hours now,and on the dipstick it is still way past the full mark.I keep checking it waiting to add fluid but it always reads past full.This is how the tractor was delivered.Maybe I bought the perpetual reservoir option and don't know it.Any thoughts.
Just looking for a reason why my new ,clean,un-scarred boom cylinders are leaking.

 

[5030]

About the only thing too much fluid can do is cause foaming and or air in the system. Leaking cylinder seals are usually caused by wear (not your case) or improper assembly. Too high of hydraulic pressure will cause seal failure and I believe that's what you are encountering.

In as much as I don't know what brand of tractor you have I can't ascertain the static pressure, but usually, pressure in the excess of 2500 psi is too much.

I presume it's a new unit so I think I'd return it to the dealer and tell 'em to get it right or don't bring it back.

 

[Soundguy]

I agree with 5030.. I don't think a slightly overfull resv. is the issue. in fact.. i own at least 3 pieces of equipment that state that the hyd sump level is filled with 'X' quarts.. but can hold 'Y' extra quarts to make up for hyd implements.. this is on my ford 5000, NH 7610s, and ford 660.

Soundguy

Can too much hydraulic fluid in the reservoir cause the boom cylinders to leak at the seals?This probably ranks right up there on my dumb question list but I wonder if it could over pressurize the cylinders to the point of leaking on a new machine.I check my hydraulic fluid every time I use the tractor because both boom cylinders are leaking since I bought it,29 hours now,and on the dipstick it is still way past the full mark.I keep checking it waiting to add fluid but it always reads past full.This is how the tractor was delivered.Maybe I bought the perpetual reservoir option and don't know it.Any thoughts.
Just looking for a reason why my new ,clean,un-scarred boom cylinders are leaking.

 

[rmonio]

This brings up an interesting point - and I'm not sure if it has been addressed elsewhere in TBN (my apologies to the guys who can search and find that out) - but, what is the rule of thumb for "overfilling" your hyd units? For example, I've had situations where both dealer service and my maintenance (using the manuals) have consistently delivered overfill measurements on my Hyd dipstick on my JD4600. I've asked the dealer about it and he said that it isn't an issue - as long as it isn't TOO far over and TOO far under, you're ok. I've tried to work within the limits of the dipstick (removing the overage) - but in any situation I've never had issues with leaks, etc., being a problem.

Call it luck - or maybe just tolerances not being issue... but is there a rule of thumb out there?

-Bob

 

[Soundguy]

This brings up an interesting point - and I'm not sure if it has been addressed elsewhere in TBN (my apologies to the guys who can search and find that out) - but, what is the rule of thumb for "overfilling" your hyd units? For example, I've had situations where both dealer service and my maintenance (using the manuals) have consistently delivered overfill measurements on my Hyd dipstick on my JD4600. I've asked the dealer about it and he said that it isn't an issue - as long as it isn't TOO far over and TOO far under, you're ok. I've tried to work within the limits of the dipstick (removing the overage) - but in any situation I've never had issues with leaks, etc., being a problem.

Call it luck - or maybe just tolerances not being issue... but is there a rule of thumb out there?

-Bob

Here is what i do... I don't like any of my sumps to be 'underfull'.. because in many cases.. your sump is rated for a certain capacity so the oil can cool.. not just because of the flow rate.

I fill my sumps to full mark.. let them settle, and then check for full. Then I use any aux hyds I have.. that is.. I extend loader bucket cyls, lift cyls, and any remote cyls. Then I check my oil.. typically it is a few quarts low then.. I refill to full, let settle, then check full again.. Then i relaxe all cyls... then I check the sump again.. It will typically now show a tad overfull.. I then take a small file or awl, and scratch a line at this new full level so next time i know where to fill it too.

On my NH 7610s, the manual actually gives an amount of oil, in quarts that you can overfill it to make up for aux hyds.. i forget the number.. but it is substantial.. though less than half of the 48 qt sump that is already there.

There is one caveat to that advice. On my old ford's that have a common sump, and not a seperate hyd sump.. I don't overfill... the axle seals and tranny input shaft seal tend to leak.. even when 'new' if oil is left to pool around them... Besides.. the sump on an 8n holds 5 gallons of diffy/tranny/hyd oil anyway.. and there are very few aux hyds use on the 8n/9n/2n anyway... And if you do.. you usually use an extrnal resvior and a pto or crank mounted pump.. etc.

Soundguy

 

[rmonio]

Well, I don't know if that's the same on the JD4600 that I have - but I've been checking regularly (after heavy use, cold, etc.) and it has never gone above or below the full line (or just a tad under it - on these dipsticks it's a shaded range that they want you to be within.

I guess I'm ok - but I find it quite odd that there can be that much give/take on the dipstick (vs. being an exact reading). I'm sure you could say the same is true for cars/trucks/etc. too.

oh well!

-Bob

 

[Farmwithjunk]

Though not always a hard and fast rule, generally, tractor designers plan ahead for oil being used for remotes, loaders, and any other such common activities on a tractor. That may not have always been, but nowdays, hardy a tractor is built that doesn't get SOME SORT of hydraulic add on.

Never go under the full mark. There's usually a safe margin where any reasonable hydraulic add on won't overtax the system. But it's safe as can be to over-fill somewhat. (Unless you have leaks that get worse with more oil, but that should be fixed in a perfect world.)

I generally add about 10% extra when doing hydraulic oil changes.

One thing to keep in mind regarding hydraulic oil, remotes, and cleanliness. Quick couplers are WONDERFUL. But they offer dirt a golden opportunity to get in your hydraulic system. Make sure they're clean before coupling (and UN-coupling too) The filters and screens may catch it, but why take any chances.

 

[Doc_Bob]

I check my hydraulic fluid every time I use the tractor because both boom cylinders are leaking since I bought it,29 hours now,and on the dipstick it is still way past the full mark.

Why not just drain the fluid out until it is at the right level? If overfilling the reservoir was the right thing to do, then why would the engineers put a max/min level on the dipstick?

When my tractor arrived, my reservoir was overfilled. I drained 1 gallon from the reservoir and the fluid is now at the max level. One extra gallon in a 11.1 gallon system may only be 9% over filled, but unless the owners manual states "ignore the max/min lines on the dipstick and just overfill the reservoir" I will assume the max/min lines are on the dipstick for a reason. If the dipstick had just a min line, (and they don't) then I would assume overfilling the reservoir was designed into the system by the engineers at the factory. Many reservoirs (like the rear end on my Ingersoll tractor) have a overfill plug. Same thing on my old 1970 VW manual transmissions. Fill the reservoir until fluid drains out of overfill plug. Wait until fluid stops draining. Then screw plug back into hole.

Bottom line, get some OEM fluid, drain the system to the max line on the dipstick and see if anything gets better or worse. There is no harm in having the fluid at the max line. There may be harm at having it overfilled. You have a great opportunity to fix it and found out if your leaks are the result of too much fluid. If the leak persists after the reservoir is correct, one possible cause is eliminated.
Bob

 

[Soundguy]

Why not just drain the fluid out until it is at the right level? If overfilling the reservoir was the right thing to do, then why would the engineers put a max/min level on the dipstick? .
Bob

I guess you missed my post. The reason you can overfill a sump is so that you can accomodate some extra fluid for aux hyds without depleting your hyd sump below minimum levels. To do this.. you will obviously be in some state of 'overfull'. As i mentioned.. My NH 7610s has a 'full' mark onthe dipstick, and the manual states I can excede this 'full' level by some substantial amount of quarts specifically for aux hyd issues.. etc.

Soundguy

 

[geneP]

Bones, painters are prone to paint the cylinder rods when the loader is painted. If the cylinder is slightly extended when painted, the paint will get under the rod seals when the cylinder is fully retracted and cause leaks. The seals will probably still need to be replaced as I've not known the paint flakes to wash out.