Rc4wd excavator valve question

[osikasculptor]

Have radio mix switch off (down) so channel 8 (4th valve) dial manually controls pressure gradually along with sound module. (channel 8 on radio e point set to 120%/120%)

This way you can set the relief valve for your max pressure and run it with the mix on or this way with a flip of the toggle. I like to dial it up or down to as needed like if you want really slow movement you can easily adjust it then back up to max. Plus the movements this way are more fluid and replicate
a real machine more the way it feels.

[Tommydude88]

hi guys... just wondering if any of ya's have done a valve rebuild on ya 4200xl yet. mine has lost it ability to hold the arm up when the pump is off, I mean all the rams just creep and lose all their preasure real quick. when I first got it was sweet at holding pressure now not so good. strength wise pump is good she still got plenty of power but yea lil bit stumped and don't realy want to pull the valve apart and wreck it completely or something like that. cheers guys

[doodlebug]

Are your servos still centered?

[Rimrock]

Originally Posted by Tommydude88

hi guys... just wondering if any of ya's have done a valve rebuild on ya 4200xl yet. mine has lost it ability to hold the arm up when the pump is off, I mean all the rams just creep and lose all their preasure real quick. when I first got it was sweet at holding pressure now not so good. strength wise pump is good she still got plenty of power but yea lil bit stumped and don't realy want to pull the valve apart and wreck it completely or something like that. cheers guys

It's a quite common problem with this machine...the original valves works okay for a couple of months, then internal wear starts showing off...Of natural reasons the expiring date is not mentioned in the sales ads..
There is several at this forum who has replaced pump or valve, or both with high end components. The rams seams to work with low level of issues over time. Just need to replace a o-ring now and than, natural wear (as is the case with high end rams too)
What many do is going for the best option at once; as change to e.g a Premacon x3 valve block, hardened steel, much more high preseason and more gaskets than in the original block..About 300 USD incl servoes & servo brackets, + order a lengt of the 4 mm tube, + a thread sealer to use on all threaded fittings. (Hydraulic fittings and hoses can be reused, but don't use the transparent hoses on the pressure side, only on the return to tank)
The original pump holds the fort a bit longer than the valve block, but it's quite greedy when it comes to power consumption..(As a factor in the race to keep costs down I suspect one has aimed for avoided installing a transmission on the pump (as the high end pumps) and installed a fairly oversized cheap low rpm motor that the pump can handle on direct drive)

[thebigo]

Originally Posted by Tommydude88

hi guys... just wondering if any of ya's have done a valve rebuild on ya 4200xl yet. mine has lost it ability to hold the arm up when the pump is off, I mean all the rams just creep and lose all their preasure real quick. when I first got it was sweet at holding pressure now not so good. strength wise pump is good she still got plenty of power but yea lil bit stumped and don't realy want to pull the valve apart and wreck it completely or something like that. cheers guys

could be the Hydraulic cylinder, leaking by the piston. my rc4wd loader bucket (tilt) is doing the same think with the pump on? I think I will pull the cylinders apart and look at the seals.

David