Bradco boom dropping way to fast.

[simmysam3]

I have a bradco 3265 attached to my TYM 330HST.

It supplies plenty of power to each of the cylinders - no issue there. However when dropping the boom it just releases - and drops almost uncontrollably. I try to manage it but it leaves me with an incremental jerky motion as I lower it at best. If I drop it super slow, barely touching the stick it will drop very gradually - far too slow to be practical. The problem is there is no "in between" where I can actually control a reasonable rate of drop.

I have run it at various RPM's, adjusted the flow control in and out, but all to no avail.

Any thoughts?

Sam

 

[oldnslo]

did this used to operate smoothly?

 

[TomSeller]

Sounds like the spool valve is faulty

 

[simmysam3]

did this used to operate smoothly?

I don't think it ever was smooth. Perhaps a "little" better than it is now.

If the spool valve is faulty, does that generally involve replacing an entire assembly, or would it be replaceable seals?

Thanks,
Sam

 

[TomSeller]

I don't think it ever was smooth. Perhaps a "little" better than it is now.

If the spool valve is faulty, does that generally involve replacing an entire assembly, or would it be replaceable seals?

Thanks,
Sam

You should be able to rebuild it. I have a Bradco 611 and the controls are very smooth every direction.

 

[LD1]

There really is nothing in the valve to rebuild.

I am wondering if this valve has load checks?

 

[KWentling]

Has a hose or fitting been replaced? Might have had an orfice to slow it down.

 

[TomSeller]

There really is nothing in the valve to rebuild.

I am wondering if this valve has load checks?

Okay, reassemble it. The spools can stick, there are o-rings that may not be sealing, etc. (particularly the one sealing the hyd fluid when dropping the boom). Spool valves do have issues from time to time, particularly if the fluid was/is contaminated. But you are right, try everything else first. Swap spools and see if the problem follows that spool. ie move dipper and boom spools (spool valve in the assembly) and see if the problem moves.

 

[LD1]

Any oring that is in the valve, if not sealing, would cause a puddle of oil.

Passages in the valve are NOT sealed off from one another with o-rings. The only o-rings are to seal the spool to the casting so oil don't come out where spool protrudes for the handle to connect, and for the spring/detent me under the can

 

[Leejohn]

Try turning the spool 180 degs. Take the can off the bottom of spool and make sure everything is right there.

 

[KWentling]

Looking a the valve parts list it shows a one way restrictor fitting with a .109" restriction on the boom section. Bottom port on the end spool on the operators RH side. I would expect that is the problem. Either missing or stuck open. I couldn't get the parts page to copy, but it is online.