4200XL hydraulic tank fill amount?

[TheBennyB]

After reading the basic manual for the 4200XL noticed it said to never fill more than 120ML of oil into the tank. Does this consider expansion or will I have to add once I bleed the system and get all functions working? Any help very much appreciated and sorry for the novice question.

[Lil Giants]

Don't know what the total volume is including cyls, but fill it to capacity with all cylinders retracted. Then using a syringe with needle, measure down 8mm from fill hole & suck oil out to that level. That should give you plenty of room for heat expansion & any possible bubbling or foaming during operation.

[TheBennyB]

Great, appreciate the tip.

[TheBennyB]

Started with 120ML as stated in the manual. As soon as I did all functions noticed lots of foam and air in lines. Retracted all cylinders and measured the fill level of the tank. Pretty low. Added another 75ML and per advice it leveled off to around 7-8mm from top of tank. All hydraulics running smooth and lines look nice and clean with no foam or air bubbles. Thanks again for the help.

[Lil Giants]

Hydraulics are quite simple in how they work... oil goes in - oil goes out through different ports. When you have problems it's 9x out of 10 it's grit in the system that's either nicked an o ring, scared a shaft creating a leak causing a loss of pressure or grit blocking a port exit. If you gotta do any wrenching on hyds, beforehand clean whatever area you're going to take apart anally with electrical cleaner & pressurized air... the slightest bit of grit can do a world of hurt to hyds!

These china models, as sloppy as their tolerances consistently are & they don't factory install any sort filter either ... a fuel filter for a rc airplane or heli is better than nothing at all. Place it within the returning oil line to the tank. As quick as "they" slap these models together without much care & kick 'em out the door... makes me wonder how thoroughly they clean machining filings from their components as they make them... atleast a filter will catch that crap too so it isn't continually flowing through the system.

[TheBennyB]

Was thinking the same thing. Have some small plane/boat filters laying around. Will probably take your advice and put one in.

[thebigo]

I tried a Micro filter, very quality one with, I think 10 microns, but it wouldn't circulate hydraulic fluid, so I went without. I have put a lot of hours on mine, but changed out the oil every 12 hours and it's working fine. I have the 1.5 version of the RC4Wd excavator, joe is right though if you can get a filter to work then do it.

David

[TheBennyB]

Will take that into consideration David. Thanks for the info.