50 Hour Service Advice

[ThreeDFlyer]

Thanks for all the great advice guys! Doing my first 50hr service as we speak.

 

[coolnick73]

I'm quickly coming up on 50 hrs on my 4520 thanks to a Woodmaxx PTO chipper. I am looking through the owner's manual and it says to replace the coolant yearly. Are you really replacing that yearly? I can see getting rid of the factory stuff and putting in a known product, but yearly? Maybe I am used to automotive coolant that is supposed to be good for 100k.

Also, does anyone have sizes on o-rings that I will probably need to replace?

 

[Omega Woods]

I won't replace my coolant every year. Maybe every two. Can't help you on the o-ring sizes but if you figure them out, please post for the rest of us. The factory ones are generally either squished or painted (or both) but I just cleaned them up and put them back on. I'll get new ones next time for sure.

 

[mechtheist]

Hello,
I thought I'd ask here and not start another post for a related issue. This is my first post also, I hope I don't look too obtuse. So I'm changing the hydraulic fluid for the 50 hr first change on my 3520H. I refill to where the level is about halfway in the window and think I should start the tractor and move stuff around which I'm figuring will make sure the fluid reaches everywhere it's supposed to go. I'm expecting the level to be lower, likely out of sight, and it is [I think]. So I start adding fluid slowly watching to see it rising in the window. I had drained about 10 gallons, it had the backhoe attached, and had put back in somewhere north of 9 gallons, seemed reasonable. Until I kept adding more and more fluid to where I had put in more than 3 gallons and it sounded like the level was nearing the top of the fill tube. So I start sucking the fluid out until I see the level back near the center of the window. Am I wrong to think that's a little crazy? I'm obviously not experienced or particularly adept mechanically.

And that makes me need to ask, is it better to change the hydraulic fluid with the backhoe attached? How much extra fluid does it add? It's the BH760. Thanks for any info/help.

 

[ericm979]

The cylinders on the loader don't drain into the transmission when the engine is off. I'd think the backhoe would be the same. So there'd be little to no extra for the backhoe.

Sounds like you just needed to stop when the level got to the indicator. Sucking out overfilled oil is better than trying to open the drain plug and only let some out.

 

[mechtheist]

That is what I did, initially. Then I started the engine, moved the bucket and backhoe around a bit. If nothing else, the new filters had to get filled. Then I rechecked the level, I couldn't see anything so I thought the level had dropped below the glass. It hadn't, it went above the glass. I can't tell whether there is oil completely filling the window or whether it's empty, is there a way besides getting the coloring? Since I was expecting it to drop, I didn't bother to try to determine whether it was filled or empty. That's why I put more fluid in. I should have sucked some out then, it probably would not have been much at all. So the mystery is how could it go from being at about halfway up the window--about the correct level, and then after I start the engine, exercise the hydraulics, fill the two new filters, and after that, have the level be higher???

When I was draining the oil, I did drop the bucket and backhoe hydraulics as much as there was room for, that made more fluid come out, not a lot, but some. How do most folks deal with something like a backhoe, just assume the fluid in it is not significant enough to worry about when changing the tractor's fluid, so don't worry about whether it't attached when you do a change?

How much leeway do you have before you have to worry about damaging something? If the level is too low, will you see the temp start to rise? Or is that already too late? My temp gauge stays pegged at halfway no matter how hard I'm working the tractor or what the air temperature is, and being in central texas, that can get pretty high. That seems like a good thing unless I'm really confused.

 

[ericm979]

I would not have expected the level to be higher either, and I've changed a lot of oil. I checked mine with the loader in the same position (down) and the top and tilt in the same position as well (but they're small).

You must have moved the equipment so a number of the cylinders were extended when you filled the oil, then had them retracted when you checked the level. When the typical double acting cylinder is retracted the volume is lowered by the volume of the rod (as there's oil on both sides of the piston). It doesn't seem like enough to raise the level from the middle of the sight glass to above the top. But I can't think of any other reason it'd be higher.

The oil in the cylinders gets filtered by the filters so unless you hooked up to a used implement with dirty oil in it, it's clean. The oil will gradually be exchanged as you cycle the cylinder. It's a small remnant compared to the reserviour so it doesn't worry me.

 

[mechtheist]

Thank you for the info. It's good to know I'm not that crazy.

 

[FMFProperties]

Well, it's done. Three of the seals were painted on and deformed. The hydraulic filter had to be removed with a screwdriver punched through the side and was about 2.5 turns past where it should have been. Coral's advice on the oil filter was much needed and appreciated.

Do they let monkeys do the final assembly on these things? I didn't expect the fill cap for the front end to have a big, nasty paint glob under the seal.

If nothing leaks, it'll be a miracle. I'll get some replacement seals before I start next time. I just poured the UTF from a 2.5 gallon jug which isn't as easy as siphoning or drill pumping but doesn't require anything but a funnel.

Thanks to everyone who chimed in.

Used Wix 51334 for oil and 51202 for hydraulic filters. The oil was smaller in diameter but the sealing surface is the same size so it fits fine. The hydraulic filter is about an inch shorter which is actually good since I'll be able to get my filter wrench around it next time without interference.

Used the same filters and had the same experience trying to get them out except a neighbor has a oil wrench that's a leather belt and uses a rachet tool to tighten and it was also about 2 or 3 turns too tight.