HST pressure loss

[TLowry]

L3400HST pressure loss

Howdy, newb here. Hoping to find a little help before hauling the machine to the shop.

I have a L3400HST with a LA463. I was digging up a stump the other night and started noticing the hydraulics starting to act weird. I first noticed the when pushing in 1st FWD, that when overloading, instead of killing the motor or spinning the tires, the system would simply growl with no wheel spin.

Next thing I noticed was the reduction of of lift/push and speed on the on the loader. Used to be able to use the raise/lower circuit to pick up the front end off the ground, now it gets it just off the ground with about 4" of ram left.

The other thing I noticed was with the bucket in the hole and curled out about 1/2, when I would start to push and without operating the curl valve, the bucket would curl out on it's own.

Machine has had a full service about 20hrs ago and fluid level is good.

Thanks for the help.

- Tom

 

[North Idaho Wolfman]

Yep you have multiple system issues, sound like they are all hydraulic related, like a leaking pickup tube that is sucking air.

 

[TLowry]

Looked at the suction line at lunch but looks good, what of it I can see. Interweb searches seem to point to this a lot. I'm gonna pull the floorboard off tonight and have a closer look.

Thanks.

 

[TexasB21]

Must be a Santa Fe thing. LOL My B21 is having HST problems also and I am waiting for my WSM (workshop service manual) from Alvin Equip.

 

[TLowry]

Must be a Santa Fe thing. LOL My B21 is having HST problems also and I am waiting for my WSM (workshop service manual) from Alvin Equip.

Funny, must be because it is dry enough work work dirt around here finally.

 

[North Idaho Wolfman]

Looked at the suction line at lunch but looks good, what of it I can see. Interweb searches seem to point to this a lot. I'm gonna pull the floorboard off tonight and have a closer look.

Thanks.

Look for any seeping (dust stuck to oil).
They can wear a hole in the back side or clamps and have issues.

 

[TLowry]

Looked it over pretty good last night, crawled all under with a light and all, didn't see any sign of a leak, no dust spots, nothing... Checked the number on the oil filter to make sure it matched the one called for my vin number, it did. Fired it up, ran the rams full stroke several times which brought the loader back to operating normally and it now hits the relief. Pushed into a dirt pile and wheels spun when over loaded.

I imagine the issue will crop up again but for now got work to do so will keep an eye on it.