cat 308d machining not moving

[andy809]

So i have a cat 308d and the nut on the bucket cylinder got loose and damaged the cylinder and also contaminated the hydraulic system everything was working except for the bucket cylinder and the blade cylinder. The problem with the blade cylinder was that it didnt have enough power to lift the machine off the ground. We repacked the blade cylinder, got a new bucket cylinder from cat. before installing the blade and bucket cylinder we removed the main control valve the bucket spool was stuck and there was metal inside the valve we got it cleaned up and repacked. We changed hydraulic filters and flush the oil from the hydraulic tank. After installing everything the machine doesnt move or the hydraulics works. we connected a gauge on the cylinders and we are only getting 1000psi. the blade cylinder its worse now and the tracks doesnt move at all. the swing moves only a little bit. The only way to get the cylinders to move its by moving the 2 joy sticks at the same time and they move really slow.

After that we removed the valve and got it checked out and we followed all the lines to make sure everything was connected correctly and the exact same problem.

can someone please help.

 

[Tyler d4c]

You got chucks stuck somewhere they arnt supposed to be looks to me a full clean out is in order

 

[Vetech63]

Its a classic contamination failure scenario. It will be a problem child until you remove every single component and thoroughly clean everything. Been there with a Cat skid loader that did the same exact thing with a boom lift cylinder. $15K later it went to the auction at the customers request........it was the best option at that point.

 

[andy809]

You got chucks stuck somewhere they arnt supposed to be looks to me a full clean out is in order

Its a classic contamination failure scenario. It will be a problem child until you remove every single component and thoroughly clean everything. Been there with a Cat skid loader that did the same exact thing with a boom lift cylinder. $15K later it went to the auction at the customers request........it was the best option at that point.

Already remove the valve twice and cleaned it. Same problem. What i dont understand why im getting only 1000psi? If i had something stuck wouldnt it give me 0 psi?

 

[Kobelco ireland]

Sounds like you have something stuck in your main relief valve.

 

[Vetech63]

Already remove the valve twice and cleaned it. Same problem. What i dont understand why im getting only 1000psi? If i had something stuck wouldnt it give me 0 psi?

Well no. You could get any pressure between 0 and the relief pressure it would depend on how bad the restriction was versus the oil flow available.

 

[lantraxco]

And worst case some chunks may have already visited the pump(s).

 

[92U 3406]

There are literally hundreds of places debris can hide on machines. Cleaning the main valve is a start but there's so much more to go through.

Does the 308D use a resolver network to stroke the pump? Wonder if there's some glitter in there?

 

[andy809]

Thank you guys this morning the machine started working perfectly fine.

You got chucks stuck somewhere they arnt supposed to be looks to me a full clean out is in order

Its a classic contamination failure scenario. It will be a problem child until you remove every single component and thoroughly clean everything. Been there with a Cat skid loader that did the same exact thing with a boom lift cylinder. $15K later it went to the auction at the customers request........it was the best option at that point.

And worst case some chunks may have already visited the pump(s).

There are literally hundreds of places debris can hide on machines. Cleaning the main valve is a start but there's so much more to go through.

Does the 308D use a resolver network to stroke the pump? Wonder if there's some glitter in there?

 

[DEMLONE70]

So what was wrong ?

 

[Vetech63]

Well maybe you got lucky but I don't think this thread is going to die yet.

 

[andy809]

Im not sure just started the machine and everything started working.

So what was wrong ?