41b Hydraulic issues

[AKKAMAAN]

He wasnt saying that it would hold load because of a weak load sensing signal, but rather what was causeing it to not hold a load would be the same thing causeing the load senseing system to not work. Weather the bucket dropping is in the valve or weather the valve has a problem with the load senseing circuit its still worth my time to take the entire valve assembly in, am I right in this logic?

Yes, load sensing problem can be in the valve....but not the spools, unless the load sensing shuttle valves are built inside the spool, which I only have seen on the Swedish Parker valve...but I haven't seen them all so...

If valve is fault in neutral would rather cause unwanted load signal...the wanted signal pressure in neutral is 0 psi.....i

 

[AKKAMAAN]

It is obviously a load sensing system according to RitchieWiki

 

[futuresweets10]

Cleaning valve and reseal do not make a lot of sense if you do not make a TOTAL CLEANING of the entire system

Clean up valve 150-250$ at the most IMO. 2-3 hr labor for a trained tech in a proper shop...resetting pressure on RV's not included....

Ive already pulled the tank and cleaned it, how do I go about cleaning the lines and cylinders?

 

[futuresweets10]

So once I get the valves worked on "professionally" how do I go about making sure there is no debris and such in the cylinders and lines?

 

[futuresweets10]

::UPDATE:: I took the valves for the front bucket off after the former cat mechanic told me that my problem was likely there. I tried taking them apart and seeing what I could find, but realized it was way over my head. I figured since I had already spent 5 hrs removing them I would have them gone through by a local shop. After $280 I got the valves back today and set out to re-install them. I found two fittings that I had damaged when removing valves and spent a good 3 hours trying to find them....

At this point I was pretty sure I had wasted the 280 and the problem didn't reside in the valves. I spent about 3 hours putting the valves back on and still the same problems. I was still hopeful that the front bucket falling was due to the valves, but after re-installation I found more disappointment.... Evidently the cylinder on the front bucket is bad. I was now back at the same point I had been at before removing the valves.:laughing:

At this point I finally decided to say "Fuc* it) and start playing with the adjustments on the pump that I had been so scared of up until this point. I went to take the dust cap off of the smaller one (the standby pressure) and ended up removing the entire top of the adjustment valve, after an hour of getting that back together it was back to adjusting. Stand by pressure was 500 and when a lever was pushed it dropped to 0 at the gauge. I started turning the stand by pressure screw after it dropped it re-set it to where It had been before and started turning the main pressure adjustment. As I turned the pressure up the pressure on the gauge went down (gauge would have been reading standby at this point). I then hit a lever and pressure surged up to 1000 and for the first time things looked like they wanted to move on their own. I set the pressure to about 2400 and then re-set the stand by to 500. I'm not sure if the stand by should be 500 or not, but for now that's where its staying. I know the machine pressure is suppose to be 2699, but im scared to turn it up that high, so its staying low for now.....

I will update this thread if necessary.... Hopefully I wont have any more issues.
Thanks for everything guys. I have learned more in the past few weeks about hydraulics then I thought existed to know and I can honestly say I couldnt NOT have done it with out the help I got from here.

 

[AKKAMAAN]

I'm not sure if the stand by should be 500 or not, but for now that's where its staying. I know the machine pressure is suppose to be 2699, but im scared to turn it up that high, so its staying low for now.....

500psi is a "normal" stand-by pressure.....the reasons, for letting pump drop pressure to stand-by, are many....
>it makes it much easier for the starter to crank engine at start up
>it reduces wear on the wear parts in the pump...especially the yoke bearings for the swash plate and also the valve plate

A too low stand-by pressure might make engine bog down a little (on low idling rpm's) when loading up to high pressure. That will impact on the pump response time....raise stand-by pressure if response time is too slow....

I will update this thread if necessary.... Hopefully I wont have any more issues.

Please keep us updated

Thanks for everything guys. I have learned more in the past few weeks about hydraulics then I thought existed to know and I can honestly say I couldnt NOT have done it with out the help I got from here.

Thank you for sharing your experiences....

Later
"oh, come on..."

When everything seems to be going against you, remember that the airplane takes off against the wind, not with it. -- Henry Ford, Founder of Ford Motor Co.