JD 410 Backhoe loader boom respond very slowly when warming

[jkk04]

Hello, Members.
I have JD 410 backhoe has some issue that loader boom respond very slowly after 20-30 minute operating the tractor.
I am sure It was not hydraulic pump problem because backhoe boom and bucket cylinders works fine even after some time operation.
So guessing the boom cylinders or control valve are leaking internally.(I don't see any leaking out side.)
Any suggestions or advice will be appreciated.
Jkk

 

[Tx Jim]

Welcome to TBN
My guess is boom cylinder is leaking internally. If control valve happened to be leaking internally the only cure is valve body & spool replacement.

 

[Dave M7040]

This image shows a small O ring seal that on some cylinder designs can fail and when it does oil can bypass the internal piston and not show any external leaks.

If you have not already done so, re seating all quick couplers can fix many problems as a partially seated one is a big flow restrictor.

Dave M7040

 

[Tx Jim]

Although I agree o-ring(key 11) can fail BUT I'll bet o-ring(key 14) fails at a much greater %.

 

[Dave M7040]

Although I agree o-ring(key 11) can fail BUT I'll bet o-ring(key 14) fails at a much greater %.[/QUOTE

First I mistakenly circled 11 when I meant O ring 18.

Certainly 14 can fail but diagnosing that failure is a no brainer. Many change 14 and still have a problem because 18 is not visible and getting nut 11 off so it can be seen is hard to do.

Dave M7040

 

[LD1]

If we are talking about loader lift cylinders, and no external leaks, if #14 we're bypassing when trying to raise the loader.....it "can" cause it to operate slowly. But usually the complaint is lack of power.