what to set releif valve on 315 cat excavator do you set it with fully retracted and fully out or just one way
What circuit and what relief ? Both for circuit and either way will do for main. The main relief is set higher and will do most the work 99% of the time If your talking about setting circuit reliefs then you will have to do both as there is one for each way
it is for the attachment bank it didn't come with a relief valve so bought one now what to set for my thumb
Do you have the relief pressure setting for the thumb from the supplier..?
No I built my own thumb using a 3000psi cylinder
Yes 3000 psi is about standard for a thumb. You should have 2 reliefs for the attachment valve and need to set both - one for extend and one for retract Also in my first post it should say main is set lower than most circuits so it does most the work - except for attachment valves
Around here thumbs are usually set around 2,100 PSI to close and that or a little more for open. As big ben says you should have two relief cartridges depending on the type of valve you bought.
bought relief valve from cat screws in the back of the valve bank is there another one that I am missing.i see there are others there for boom/stick/bucket
That doesn't guarantee it's the right one ....... do you have a Part Number..?
085-8724# in the parts book the one they sent me is 107-6917
There should be 2 line reliefs put in the top and bottom of the auxiliary section of the main control valve. Set them both to about 2200 or max 2500. Run the engine about half throttle when testing pressure.
Got looking in parts book and now I see there is one in the bottom too never noticed it before the way i hooked it up was double action/ single pump thanks for all your help guys.
i only put one releif valve in set it at 2000psi on the retract side but bucket won't push thumb in or do i have to have one on the other side in order for it to work can't get another anything being long weekend.
Your relief should be set so that curling the bucket just over rides the thumb
I thought at 2000 it would over ride but have to set it lower maybe when I try the bucket just makes small squeal noise
A relief valve on the retract side only releaves the rod end of the cylinder. In order for the bucket to force the thumb back you will need a relief valve on the barrel end of the circuit in the auxiliary valve.
You need to put the relief on the barrel side. if you dont have a relief for the rod side dont worry, you can run full system pressure there.
I think I have it on barrel side when I checked it was 2000psi when I sucked the cylinder in.When I push on the thumb cylinder out it goes way over. Unless 2000 is a bit to high .
Its the same relief that is used when you push the thumb out against the bucket. Start by backing the relief right out, then turn it in a half a turn at each try while curling the bucket in and the thumb pushed against the bucket. Keep doing this till the bucket struggles to push the thumb back in. At this point, back off the relief a quarter to a half turn further. This will let the bucket just comfortably override the thumb. This should all take place when the thumb cylinder is perpendicular to the thumb (where the thumb has is greatest force). Now you will be able to roll (curl) material back and forth while holding on to it with the bucket and thumb, and the power of the bucket cylinder won't damage the lighter components of the thumb.
You've got the relief on the wrong side. Sucking cylinder in is rod end pressure.
okay thanks I did have it on the wrong side