Everything at once....

[TruChaos]

Had a bad day today


1) Weak backhoe function

After 4 years in storage, I finally installed my YW-6 backhoe. It worked fine but after an hour it became weak. I quit for the day checked the hydraulic fluid level and it had dropped a bit, so I topped it off and returned to work the next day. It was fine for 45 minutes or so then it started getting weak again. It was hot outside at 96 degrees. When the fluid is hot it won't lift the boom with dirt in it. Without dirt it lifts fine but quickly droops so that every couple minutes I have to lift it again. When I say it gets weak I mean all the cylinders are weak, bucket curl, boom curl, boom lift. Yet I can hear the tractor engine load. This only appears to happen when hot.

The sway cylinders screech when the boom is swayed then the lever is released.

Is AW32 too thin?

2) Excessive transmission noise.

The transmission has suddenly become very noisy. Especially in the high range and 3rd gear but all gears make lots of noise. Reverse is pretty quiet. I had noticed that it seemed noisier than usual but now I can hear it over the engine with the engine running at 2200 RPM. The transmission oil is fine and was changed twice (after the initial flush) in the first 150 hours. Looking at the dipstick even after just a minute or so of use it's very foamy looking. No water in it, but it appears white and close inspection reveals lots of bubbles.

3) Before I installed the backhoe, the PTO lift began drooping after a few minutes.

4) Hit a ground bee nest (yellow jackets) with the backhoe. : (


Any suggestions?

 

[greg_g]

Is AW32 too thin?

Might be. I have a problematic pressure relief valve in my steering pump. It's ok in the fall/winter, I run AW32. But soon as it it starts to warm up in the spring, I have to replace it with thicker fluid. Tried AW46/64/100, all too thin. Went to50W racing oil, cuz I can't find AW220 around here. Works fine now; AW32 fall/winter, 50W spring/summer.

No water in it, but it appears white and close inspection reveals lots of bubbles.

That would be emulsion; a semi-permanent mixture of oil, water, and air. Once emulsified, the water doesn't settle back out again. You'll have to be the judge how/where the water is getting in. But the bubbles are generated when the oil is splashed by the spinning gears. Given time the air bubbles will disappear, but the water will stay in suspension. You'd best drain/flush/replace.

Before I installed the backhoe, the PTO lift began drooping after a few minutes.

Likely the same problem that's affecting the BH.

//greg//

 

[RonMar]

Well crap in the oil coild be causing relief valve issues. I would highly reccomend getting a metric to NPT adapter and a hydraulic pressure gauge so you can confirm where the relief is opening. Your BH probably uses straight metric to o-ring face seal adapters where the hoses connect to the control valve. I think the ports on the valve are 18MM X 1.5MM. You can unscrew one of the adapters and screw the gauge and adapter into the port and send fluid to that port to see what the peak pressure is getting up
To.

 

[20 20]

same thing happened to mine, ended up being a bad O-ring in the valve. It was hard to find but easy to fix, harbor freight sells the metric O-rings that will fit. Just get the kit that has all different sizes one of the best buys I ever made, next to zerg fittings.

 

[TruChaos]

same thing happened to mine, ended up being a bad O-ring in the valve. It was hard to find but easy to fix, harbor freight sells the metric O-rings that will fit. Just get the kit that has all different sizes one of the best buys I ever made, next to zerg fittings.

Now that you mention it, the boom lift lever sticks a little when pulled back. Sometimes if I don't push it back, it stays back. Maybe there is a seal hanging up. I have one of the o-ring sets you mention and will take a look when I can.


Greg, thanks for the hydraulic fluid info, since this is the first fluid the system has had in it since manufacture, it needs to be flushed, so I think I'll go with a more viscous oil. Regarding the transmission oil, I really don't think it's water in the oil. I've seen oil water emulsions before and it has a milky look to it. This is clear oil with lots of bubbles. Much like oil without anti-foaming additives. Additionally, the tractor is stored in doors and has never seen rain so I can't imagine where the water would have come from, aside from a yearly light spray of with a hose (surface dust).

The transmission sounds like it has no oil in it. Can gears and bushings in the transmission be somewhat easily replaced?

 

[TruChaos]

I opened the transmission and everything looks good. No water. I opened the side panel and looked at the shuttle shift gears. No broken or obviously worn teeth. The two shuttle shift gears have grooves in them but the grooves are so uniform, I'm sure they are there from the factory.

I suppose the noise could be coming from the rear end.

Any thoughts?

 

[greg_g]

Greg, thanks for the hydraulic fluid info, since this is the first fluid the system has had in it since manufacture, it needs to be flushed, so I think I'll go with a more viscous oil. Regarding the transmission oil, I really don't think it's water in the oil. I've seen oil water emulsions before and it has a milky look to it. This is clear oil with lots of bubbles. Much like oil without anti-foaming additives. Additionally, the tractor is stored in doors and has never seen rain so I can't imagine where the water would have come from, aside from a yearly light spray of with a hose (surface dust).

You said it was "white", which I interpreted as milky. But yes, non-foaming gear oil that's labeled as yellow-metal compatible is the majority recommendation. If you've never changed the tranny/diff oil, then it's hard tellin' what's in there. But you'd be surprised how wet gear oil can get just from simiple condensation. My 454 is stored in an open faced shed. You'd think that'd be enough, but the dirt floor holds a lot of moisture. Even when it's caught outside, most rain is shed by the canopy. I followed the majority recommendation at the 50 hour flush-n-fill, yet had obviously milky gear oil by the time I changed it again at 300 hours.

//greg//

 

[TruChaos]

Went to50W racing oil, cuz I can't find AW220 around here. Works fine now; AW32 fall/winter, 50W spring/summer.
//greg//

Greg, this is great to know. Since I want to flush the backhoe system of any original Chinese oil, I'm going to try thicker oil and see what happens. My only concern is the thick oil with the stock tank strainer. I'm wondering what the upper limit for viscosity is with the stock strainer.

The stock transmission oil was changed immediately upon receiving the tractor. The transmission oil I replaced it with is safe for copper and brass but it does foam considerably, I can't remember the brand. I really don't use the tractor in motion very much so excessive gear noise is surprising to me. . Chipping and the backhoe are the top uses. The frontend loader gets used but not too often and always in first gear, low range and very slowly.

 

[greg_g]

The OE strainer should be ok, but you can always replace the suction screen. I buy 80x80 (80 micron) brash mesh to replace mine once a year or so. Not expensive - easier than cleaning the old one - cuts with a scissors - wraps in place without difficulty

If it helps, I'm using Coastal gear oil. I corresponded with the company engineers and got a written guarantee from them that it's both non-foaming AND safe for yellow metals. I asked because their containers don't specify this. The response was that they bought so many million pre-printed containers under contract - and have to exhaust that supply before having new containers printed with the "non-foaming" and "yellow metal" properties.

//greg//