CAT 303.5 - Blade Valve Stuck

[greygizmo]

Starting a couple months ago I noticed I was having a hard time moving the blade control lever when first starting the machine. Eventually, it would move and all would be good the rest of the session.

In the past I tried more grease on the cylinder pins, using the bucket to raise the front end and quickly "dropping" the blade into the ground, etc.

Today the weather is about 15F and I can't get the blade loose at all.

Honestly I'm not sure if the issue is at the cylinder or in the hydraulic valve that the control lever connected to.

What would you guys try?

 

[Nige]

What would you guys try?

Uncouple the cylinder from the blade maybe.?

 

[Tags]

Does the control lever in the cab for the blade move? Is it a cable controlled valve or pilot controlled? Like Nige said, drive the pin that attaches the cylinder to the blade out, cock the boom sideways and turn the house so the bucket stick and boom lines up over the blade, and see if you can gently and effortlessly lift the blade with a chain.

 

[greygizmo]

Thanks for the suggests guys. After posting I ran to Tractor Supply to grab a refill for my MAP gas torch. I was going to heat the joints a bit to see if that helped.

I was gone a half hour. Decided to try one more time and blade moved just fine. Overall I had the mini running for about an hour before that success.

So it does loosen up and operate fine eventually. Before then, the control lever will not move. I believe it is pilot controlled - the lever sits right on top of the valve and is directly connected to it. It feels like something is physically stopping the lever from being pushed forward or backward.

 

[Tags]

It “sounds” like a cable has moisture in it and once it warms up it’s fine. Or the throw of the valve is freezing because water has melted and refroze on top of the valve??

 

[greygizmo]

I think you might be right... I found a small tear in the boot that would allow for that to happen

 

[Tags]

Is it open cab?

 

[greygizmo]

Is it open cab?

Yes it is

 

[LNAL]

Hi, i just bought a 2002 cat 304 with an open cab and the blade is stuck in the up position. If i pull the lever i can ear the engine\pressure but when i push on the lever to go down nothing happens, feels like its blocked/jammed…

 

[Nige]

i just bought a 2002 cat 304 with an open cab and the blade is stuck in the up position

Please post a Serial Number to look up parts. NAD-prefix maybe.?
I would guess you are in for disassembling the control valve and cleaning at best and some replacement parts at worst.

If your machine is an open cab take a good look at the rubber boot for a split as per the photo posted above. Water/dirt getting in there will play havoc with the control valve.

 

[LNAL]

Hi, thanks, yes 304KNAD02218

 

[Nige]

Does the installation look like this.?

 

[LNAL]

Yes exactly

 

[Nige]

Here's the parts breakdown. I see some diassembly in your future because it would appear at least one of the spools in the valve may be stuck.

 

[LNAL]

I got the valve to the hydraulic shop. Hopefully it’s a simple fix. Remplacement is 2600$ cad from cat.
I was debating letting the top part soak in diesel. Do you think I can join the hoses and use the machine with the blade up? If so which ones should I join?
Thanks
Ernest

 

[92U 3406]

It probably will not stay up with just the lines to the cylinder plugged off. There's probably too much air in there that'll make it drop.

Probably no decent way to chain it up so I would just unpin the blade and cylinder and run with no blade if it were me. Bear in mind that having the blade down while digging over the idlers adds a decent amount of stability to the machine as well.