Bucket cylinder internal damage, what to look after repair?

[pados1002]

Hey guys, my EW180C Volvo had a bucket issue, where it would open or close under it 's weight. Cylinder dissembled and carnage showed up. Tomorrow I m waiting the cylinder back from the machine shop. What I want to ask is what should I look for before I put the machine back to work? Debris and metal pieces is possible to have gone through the hoses in MCV or some other blocks? What do you recommend that I should do or clean?
Regards!

 

[pados1002]

UPDATE. Cylinder was repaired and returned. Now new and more serious problem occured.
Debris and metal chunks is found in control valve and spool is scratched. Only on the bucket line. Please give some advice. How can I find a replacement spool? Volvo is not selling spools separately for this control.

 

[Simon C]

Start looking for a good used control valve. You will have bigger problems with the condition of that spool. Maybe someone else know where to find one.
Simon C

 

[Nige]

How can I find a replacement spool?

You can't. The outside diameter of the spool is matched to the valve body when it is manufactured. That is why replacement spools are not available.

I would say you probably have debris from that cylinder failure right the way through the hydraulic system by now. Have you removed and cut open the hydraulic filter(s) yet to inspect for particles.?

Theoretically speaking the only solution is to remove every hose, every control valve, every cylinder, every pump, centre swivel, travel/swing motors, the tank, and anything else you can think of and clean each piece out. It is the only way that you can even attempt to ensure that the system is clean.

 

[pados1002]

So no hope? I ve been looking for a control valve days now and nothing. New ones are prohibited. From 20k in China to 40k here in Greece from Volvo. I changed the filters in the hydraulic tank, and some debris found in there. I cleaned the tank it self. Now I m trying to save my self from paying for a new MCV that probably costs more than the excavator. Do you think that machine shops that deal with hydraulics could possibly help me?

 

[92U 3406]

If this is a situation where the machine will get scrapped if a new MCV is cost prohibitive you could go full bush league on it. Pull and pig all the lines you can reach, clean out the reservoir and pull your current MCV and lightly polish the high spots on the spool and bore. Clean out the MCV and cross your fingers that it works.

I in no way endorse or stand behind the quality of what I posted above. Do at your own risk because it may all just end up being a waste of time at the end of the day. Proceed at your own risk. Like I said if the alternative is junking the machine you might get lucky and get some more use out of it.

 

[pados1002]

I guess I ll start by reaching the machine shop that repaired my hydraulic cylinder with the hope that he can help me. If not I ll try diy stuff like you mentioned @92U 3406 , because it 's just crazy that you cannot ask for a spool from the company that manufactured the Mcv (Linde in this case) even though they probably have all the data needed to help you. And the second most disappointing thing is that I can find almost anything else in the used market, but this one.

 

[Vetech63]

I’ve polished spools worse than that. Polish the scratches out of that spool until it slides smoothly in the valve body bore. You really have nothing to lose but a little time if it doesn’t work.

 

[pados1002]

What method so you propose @Vetech63? I mean a sandpaper of like 3000 or 4000? Maybe higher number?

 

[crane operator]

Some magnets in the hydraulic tank wouldn't hurt, if you're going the hope and pray route. It might catch some of the trash before it heads for the pump.

 

[Vetech63]

What method so you propose @Vetech63? I mean a sandpaper of like 3000 or 4000? Maybe higher number?

I use Emory cloth, the finer the better.….probably a 300 grit or more. You want a nice smooth fit…..you may not need to get every scratch out so don’t overdue the polishing.

 

[pados1002]

I use Emory cloth, the finer the better.….probably a 300 grit or more

Thanks for the advice. I ll try with caution!

 

[92U 3406]

I usually finish with about 600 grit. I have done light honing in the bores just to talked down any high spots.

Like Vtech said, you're not trying to take the scratches out. Just want it to slide freely.

 

[LCA078]

May also want to run a hone or light sandpaper to knock down the high spots inside your valve housing. If you don't have a hone, use emery cloth wrapped around a tube or such that is about 90% the diameter of the valve housing diameter. Use a hand-held drill with lots of oil (hydraulic oil is perfect) and run the cloth at high speed up and down like you're honing an engine cylinder.

The trick is to have a long strip of the emery cloth and attach one end (I just use duct tape) to the rod/tube/etc. and wrap it in the direction opposite the spin of the drill. This keeps the strip of emery cloth wound fairly tight on the rod as you hone the cylinder. When that section of emery cloth wears out, tear it off so that you have fresh emery cloth exposed and go at it again.