PC200LC-8 is having Hydrolic fluid back feeding by travel spool cap

[Pauly17]

I'm having Hydrolic fluid coming out of my travel spool cap when I was testing travel Pilot pressure. When testing the left forward pilot pressure the pilot pressures fine but when I pullback on the control to go in reverse it will spray Hydrolic fluid out of the travel spool cap. Any ideas what could be causing this? Can I pull the travel spool out to inspect? I'm having issues with the travel only on the left side it seems. I checked all the pressures both high and pilot and this is the only thing that is happening that doesn't seem correct.

 

[funwithfuel]

So, to be clear, you remove and cap the hose to the spool cap. You leave the cap open to atmosphere. You apply pressure to the opposing spool cap via RCV( travel pedal) and oil jets from the spool cap? If I understand correctly, that would indicate a fault in the spool or valve section. Yes, you can fully withdraw the spool from the body. Make sure you pull a vacuum on the tank and vent off all residual pressure or you're gonna have some really soft skin .
What type of problem are you having with travel? Have you pinned the track to measure pressure? Have you inspected your filters, measured case drain, looked at track sag, checked sump and strainer. .

 

[Pauly17]

Thanks for your reply. We lost power and I’m answering with my phone. I’ll get back to you as soon as I get power back. And Thanks again for your reply funwithfuel!

 

[Pauly17]

Ok so you are correct that it is back feeding through the spool cap. I have replaced the travel pilot assembly all 4 accumulators, and also rebuilt the swivel joint hydraulic assembly. All pressure in the computer run the same travel pressures also for each side Left or Right track. What it does is when you run full forward all is fine. If you back out of the left pedal (Like to turn Left) then go to go back to full forward it will not go full forward. It just goes slow or keeps turning. Now when it is doing this if I hit any implement it will go straight back running 100% fine again. So when this is acting up like this going slow or still turning instead of going straight if you say hit the thumb button it will corrector itself and go full forward like it should. From my understanding there is a switch that has all the implements get the same amount of hydraulic pressure sent to all them. When this happens and the hydraulic pressure equalizes everything goes back working 100% correctly.

So, to be clear, you remove and cap the hose to the spool cap. You leave the cap open to atmosphere. You apply pressure to the opposing spool cap via RCV( travel pedal) and oil jets from the spool cap? If I understand correctly, that would indicate a fault in the spool or valve section. Yes, you can fully withdraw the spool from the body. Make sure you pull a vacuum on the tank and vent off all residual pressure or you're gonna have some really soft skin .
What type of problem are you having with travel? Have you pinned the track to measure pressure? Have you inspected your filters, measured case drain, looked at track sag, checked sump and strainer. .

 

[funwithfuel]

I believe you are referencing the merge/divide valve. I would be more concerned with the condition of the spool. Are the lands scored or gouged? Is there chunks missing from within the valve section. There shouldn't be constant oil pressure out of the cap. A trickle after a squirter is to be expected but not constant pressurized flow. Good luck

 

[Pauly17]

I believe you are referencing the merge/divide valve. I would be more concerned with the condition of the spool. Are the lands scored or gouged? Is there chunks missing from within the valve section. There shouldn't be constant oil pressure out of the cap. A trickle after a squirter is to be expected but not constant pressurized flow. Good luck

I checked both ends the the spool this am and neither side at the ends were scored but I didn't pull it all the way out yet. I didn't want to loose fluid. When I get some time I'll pull it out and check it. This diagram of the spools Number #8 shows the end of the spool has that part and an o-ring. Is that suppose to turn or move in or out? Mine do not move at all. I was just wondering if that is a pressure release valve?

 

[funwithfuel]

I don't remember to be honest. I'm going to ask for help from LACHAU and JohnC. They know these older models far better than I

 

[Pauly17]

I don't remember to be honest. I'm going to ask for help from LACHAU and JohnC. They know these older models far better than I

Ok so I just ordered the main control block and spools for my machine. The block had a wear mark on it and the high pressure was getting past bleeding into the pilot pressure. I want to thank you for your help on this! Thanks again funwithfuel

 

[funwithfuel]

Ok so I just ordered the main control block and spools for my machine. The block had a wear mark on it and the high pressure was getting past bleeding into the pilot pressure. I want to thank you for your help on this! Thanks again funwithfuel

While I'm glad to see you found something to validate your concern, I'm sorry it is so damn expensive. Good luck.

 

[funwithfuel]

Don't forget, valves are not simply plug and play. You're going to have to perform a full PM clinic to get everyone where they need to be.

 

[Pauly17]

Don't forget, valves are not simply plug and play. You're going to have to perform a full PM clinic to get everyone where they need to be.

I am just getting the block and spools and everything else I'm just moving over from my old one. I hope all the old setting will work. If not, I'll have someone from Komatsu come and go through it. Thanks for the heads up!