iDRY Vacuum Kilns

Sponsors:

Tree Farmer C5D Steering

Started by jdatwood, May 05, 2018, 08:25:31 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

jdatwood

Good evening all,
Hoping someone can help me with an issue I have in my steering. I've taken the valve and replaced all the seals so it doesn't leak anymore and now when I steer it's very weak unless I have the blade all the way up or down with the blade control actuated (dead heading) at the same time I steer. I don't know if it just needs to be run a bit to purge the air or if there's an issue in the priority valve inside. I don't have a schematic of that valve. If anyone has run into this or has a valve schematic I'd love to see it. I cannot imagine it's something in the valve other than one of those ball bearing seats maybe not quite in right and I doubt that. 

mike_belben

Im gonna guess the blade spool is downstream of the steering spool or orbital valve.  That the pressure rise in the circuit is from the blockage being created by the blade spool, and that this is the pressure that is making your steer circuit work.  

If my guess is correct it indicates that your steer spool is not building full pressure, because the path back to tank is not being fully blocked by the steer spool or the relief in that circuit is bypassing.   

This could be a relief in backwards or spring missing, trash in the seat, seal/oring issue.  Could be valve spool backwards, in the wrong bore, misadjusted, detent or back cap issue, maybe plumbed wrong i guess..  Lot of ways.  A gauge will show the low working pressure and a temp gun may indicate the leaky spot.  Fluid flowing over a valve generates heat.
Praise The Lord

jdatwood

Okay, thanks for that detailed response. Your correct, the blade spool is downstream of the steering valve. Sounds like I need to pop out those spring/ball bearing units (not sure what their called). One must be bound up or spring in backwards allowing leakage past the ball. What your saying makes perfect sense to explain what's happening. I'll give that a go and see what I can find...

mike_belben

Yeah it should make pressure from pump to steer valve and have almost none in the exhaust port, but something is failing to divert flow to the rams and block it from continuing down stream (either to tank/exh port or to power beyond port depending on how it is configured)

When you hit the blade you are blocking flow past that valve and creating pressure rise everywhere upstream so that even the exhaust side of the steer valve has sufficient pressure to move the rams.  Youll get more force by pushing blade into the dirt than lifting because its heavier.  The pump needs a load to build pressure into.


I cant tell you exactly what, but something in that steer valve is bypassing.
Praise The Lord

jdatwood

Your correct about that, when the blade is pressed down firm on the ground and front end lifted the steering will waddle like nobody's business. I'm gonna go pop those caps off this afternoon that hold the spring and ball bearing seat in to see if one is jammed crooked or something. I can't imagine it being a relief valve due to me not touching them other than to replace the outer seal so they don't leak outside the valve body. I'll let you know what I find. 

Corley5

My C4D forwarder did the same thing.  I took the valves off, took them to a hydraulic shop where they were rebuilt and the problem was solved. :) 8)
Burnt Gunpowder is the Smell Of Freedom

jdatwood

Something to be said for the easy button! 

jdatwood

Quote from: mike_belben on May 06, 2018, 08:57:09 AM
Yeah it should make pressure from pump to steer valve and have almost none in the exhaust port, but something is failing to divert flow to the rams and block it from continuing down stream (either to tank/exh port or to power beyond port depending on how it is configured)

When you hit the blade you are blocking flow past that valve and creating pressure rise everywhere upstream so that even the exhaust side of the steer valve has sufficient pressure to move the rams.  Youll get more force by pushing blade into the dirt than lifting because its heavier.  The pump needs a load to build pressure into.


I cant tell you exactly what, but something in that steer valve is bypassing.
Well...... I fixed it! It wasn't an issue with the relief valve, though I did find a piece of o-ring close to one of them so just a matter of time and that would've been an issue. Here's what I found.. when I removed the valve to rebuild it there was a stack of washers under each mounting bolt. They were there to give the steering wheel linkage room to clear the shelf it mounted on and allow the valve to actuate. Since I was in there I replaced both rod ends on the linkage as they were both worn all out and sloppy. Someone had even smacked them with a punch in an effort to tighten them back up. The extent people will go to save $25 is amazing... Anyways, since everything was tight I figured the janky set of washers wouldnt be necessary. Turns out I still need the washers to provide ample clearance (poor design). It just so happens when the wheel was turned the other direction it was hitting a hydraulic fitting. Basically I had the perfect storm of hitting things no matter which way I turned the wheel. It turns out the valves do all the work in that last 1/8" of stroke and I wasn't quite there. I never noticed it was rubbing as it was such a tiny amount AND when the dash cover was mounted the dash changed angles ever so slightly compounding the issue. Anyways, thanks for your help! Your clearly well versed in fluid power. 

mike_belben

Glad to help bud.  That would do it.  If the valve spool cant go full stroke then the lands never fully block the tank passage.  Fluid always chooses path of least resistance to equilibrium pressure.  Current too actually.
Praise The Lord

Thank You Sponsors!