hydraulic cylinder replacement???????

avclay · Jul 29, 2005

I posted under the NH area about my foamy hydraulic fluid due to a leak in the bucket cylinder. The fluid may not exactly be foamy, maybe milky would be a better description, but I know air is getting in there and it needs to be taken care of (thanks to the responses so far). So, my major leak is from the bucket cylinder on the top of the cylinder where it had obviously been repaired (welded) before. My questions are: should I try getting it welded again or replace it all together? Obviously, another repair will depend on the cost of a new cylinder but right now, I can't seem to find any idea of price. So far I've stumped TSC (not hard to do around here) and my NH dealer, although I have to get back to them with some more info. Its a Dual model 105 loader which has since been bought out by woods so I'm thinking a new cylinder ain't gonna be cheap.
The other consideration is I've got projects going on right now I really need this tractor for, but I suppose thats always an issue. I need to spend time on the projects, not fixing on the tractor. I've also got a lift cylinder thats leaking around the seal, but I know I can just get a rebuild kit and do that is a few hours.
So, any suggestions on which way to go and any info on who to look to for new cylinders would be appreciated.
BTW: I don't know how to weld so I have to beg off of friends who do to get it done......

Bob_Skurka · Jul 29, 2005

I would pull the cylinder and take it to any local hydraulic shop.

They will be able to look at the cylinder and either do the repair or get you the correct replacement. I use a local shop for various forklifts and such, I've found they have 10,000 square feet of cylinders, valves, hoses, etc. Compare that to the tractor dealer or the TSC store and there is no comparision. If they don't have the exact part, the hydraulic shop can usually get it quick. A TSC probably won't source it. A deal will, but it could take them hours or days to find the right one, and they will probably order it from the hydraulic shop! Just a thought.

ronjhall · Jul 30, 2005

<font color="blue"> maybe milky </font>
I'm not sure how to replace the cylinder. But "milky" looking oil usually means there is water in the oil.

MadReferee · Jul 30, 2005

As has been already suggested, a local hydraulic shop is your best bet for getting the cylinder repaired CORRECTLY. If they can't repair it themselves they can get replacement parts faster than any TSC or other tractor dealer. However, if it's beyond repair and is a speciality cylinder that has no common relpacement then the NH dealer would be your best bet for a new cylinder.

I would not work that tractor too hard, if at all, as long as there is foamy/milky fluid. The cost of replacing a pump and other seals is way more than the cost of any downtime and/or cylinder repair. But then again, it's your tractor and your money. /forums/images/graemlins/confused.gif

AntrimMan · Jul 30, 2005

The gent's above know it best. Go to a shop for a replacement, done right, done once.
Just curious though, how have you determined the fluid is milky? Is there a sight glass or is it obvious on the dipstick? How is it possible for air to enter the system through a cylinder? With pressure applied to one side the other side is forced to exhaust and vice versa, what I'm trying to say is that no side of the cylinder is ever under less than one atmosphere so how does the air force itself in? Hmmm... I don't get it.
I think the air is either coming from the suction side of the pump or the pump is cavitating. I don't know much about a lot of things so I may be dead wrong. I just don't get it.

Wait, wait a minute, here's a thought. If the pump is not running and a cylinder relaxes then I suppose the air could enter if vacuum is created by the moving piston. Is that what happens? That would only be a small quantity of air in comparison to the sump capacity and would be quickly expelled. I am still not convinced the milky fluid is caused by a leaky cylinder.

All the best,
pondering Martin

MMM · Jul 30, 2005

Are you losing fluid from the suspected air leak? It's quite odd that a leak there would cause excessive foaming. All oil that passes through the cylinder should go to tank where air would dissipate unless you were really doing a lot of cycles. If your loader is double acting (downpress) I can't see this happening as oil is forced into cyl in either direction and there shouldn't be any suction. I've had equipment that seeped badly at seals and didn't cause any foam, just high consumption. Most cavitation and foaming problems originate on suction side of pump. Are you running a loader pump (front pump)? I would look for a leak between pump and reservoir. Have you let tractor set a day and check hyd oil to see if it clears? Air will dissipate fairly quick, while water will emulsify with oil and stay milky.

slowrev · Aug 1, 2005

As MMM said air in the fluid is usually caused by a leak on the suction side of the pump. I found one that did not leak fluid, but would suck air. Replaced the fitting and all was well.

Foamy fluid is due to an suction leak or incorrect hydraulic fluid. Milky whitish fluid is caused by moisture in the fluid. Replacement of the fluid is the only way to fix this problem.

Both milky and foamy fluid are not good for your pump.

Ben

avclay · Oct 14, 2005

Tks for the replies guys. The fluid does clear quickly after the tractor has sat. I assumed the leak was from the cylinder because that appears to be the biggest leak, however, that is slight also. I've yet to have to add any fluid.

I'm not sure what cavitation is. I know the seems to be a "bump" in the hydraulic system occasionally. I don't know how to explain it other than when operating, the system will surge, creating a bump. I can see the hydraulic hoses actually moving with the surges. This condition doesn't seem related to any specific situation, sometimes it happens when cold, warm, working for awhile, at start up. There's nothing consistent about it

MMM · Oct 14, 2005

Occaisional surge is most likely caused by the air which compresses and therefore requires less power and a momentary rpm increase. The cavitation will eventually cause pitting in your pump. You never did say if you were using a front pump or plumbed off hitch system.