Front End Loader Pressure check

[dex3361]

My friend has a L4400HST and was questioning the FEL lift ability. The first pic the location of pressure relief block. The second pic is the hex head that holds the pressure relief spring and adjustment shims.

 

[J_J]

My friend has a L4400HST and was questioning the FEL lift ability. The first pic the location of pressure relief block. The second pic is the hex head that holds the pressure relief spring and adjustment shims.

What is the question?

You should check to see what the relief pressure is, and check the pump pressure. Relief pressure should be 50 to 100 psi below pump pressure. If the machine can not lift the advertised load, there are problems somewhere.

 

[dex3361]

Before we did any adjusting of course we checked the pressure at the FEL quick connect. We held the control valve open till the guage topped out at 2540PSI with the engine turning about 2000 RPM.The Specs call for a max of 2631PSI. We used a wet dry vac attached to the hydraulic fill opening and on to keep from loosing any hydraulic fluid. The pick of the valve with the releif valve spring removed is with the resevior full and the vac on.

 

[dex3361]

Not really a question just a post on the process and of course running it by the knowledge board for technical accuracy. I have read a lot of your posts JJ and I always am amazed at the vast knowledge and skill that shows in the gadgets that you make and the reliable advice given.

 

[dex3361]

We removed the spring/shim holder of the relief valve and I included a pic for clarity also another pic of the valve body that is a little clearer. the original pressure of 2520PSI is about 110PSI low and he wanted to put it at the top of the acceptable range. The shims add aprox. 38.4PSI for each 0.1mm added. so we added 0.3mm shims the existing shims and reassembled the spring assembly.Threw a shim still in the package for reference in the last pic.

 

[dex3361]

The results are in the first pic with the pressure pretty muckh on spec at 2630PSI. My friend tested the loader and says he can tell a difference in the added 110PSI. I had adjusted the relief on my tractor a few months ago and I wanted to document the process for the next person who might want to check or adjust the pressure relief on their tractor (mine is a Kubota L4400 as well).

 

[J_J]

You have to be careful here. If the pump gets a little weak and loses some psi, then by you raising the relief valve settings, you just might set the relief valve at a higher psi than the pump, and the relief will never come on.

 

[J_J]

dex3361

I would write down the pressure, while the tractor is new, to use as a reference for later truble shooting.

 

[dex3361]

Good Idea JJ I have mine noted in my tractor log book(original PSI and shims added) and I will make a not of the one we did today. I made sure we did not exceed the factory spec and the pressure that we set the unit at today is in the acceptable range. The acceptable range is 2489PSI to 2631PSI out of a Kubota shop manual. By the way when I did mine it was 280PSI low and was actually below spec. It made a very noticable difference.

 

[Willl]

Did you figure where this leak is coming from ?

 

[dex3361]

When we hooked up the wet dry vac it was hooked up backwards and when I started to remove the relief plug a little oil came out. About a cup came out of the tractor but most of that was on me.

 

[KubotaNewb]

Dex3361,
I am going to purchase the kit I seen on here and test mine when I get it in. You hooked the wet/dry vaccum up just so the fluid did not leak while changing the shims correct? Also if I do test it and the pressure is below factory specs, is that something I should take to the dealler and have them check/adjust under warn?

 

[dex3361]

Dex3361,
I am going to purchase the kit I seen on here and test mine when I get it in. You hooked the wet/dry vaccum up just so the fluid did not leak while changing the shims correct? Also if I do test it and the pressure is below factory specs, is that something I should take to the dealler and have them check/adjust under warn?

If it was very low you might have the dealer deal with the issue. With that in mind it would take less time to adjust the pressure than load the tractor on a trailer let alone haul it in. The tractor that I adjusted the pressure on was the second one that I did and it only took a few minutes pictures and all. The shims were a few dollars for a an assortment and I would rather service my own machine.

 

[BGBill]

Randall,
Where are the pictures ? I would like to see where the valve is that gets shimmed.
BGBill

 

[BGBill]

I have a BX25. Should have mentioned that. I'm looking for a picture that shows the valve on the 25.

thanks, BGBill

 

[J_J]

This is a BX24 Showing relief valve/

http://www.tractorbynet.com/forums/...4487-bx-christmas-present-dsc03214-small-.jpg

http://www.tractorbynet.com/forums/...4487-bx-christmas-present-dsc03213-small-.jpg

 

[dex3361]

Randall,
Where are the pictures ? I would like to see where the valve is that gets shimmed.
BGBill

Sorry I should have added the link so here it is.
L4400HST FEL Pressure Check and Adjustment.

 

[Piston]

Thanks for posting this, I have a L4610 and also think my lift capacity isn't what it should be. I have wanted to check the pressure and will do so the way you showed. Where do I get one of those fancy quick connect pressure gauges?

 

[J_J]

You make one up. Obtain a 3000 psi hyd gage , a short hose, and QD fitting for the end. Plug the QD into one of the valves and activate the lever, and the pressure relief psi setting will show on the gage.

Or put a QD on the gage.

 

[dex3361]

Thanks for posting this, I have a L4610 and also think my lift capacity isn't what it should be. I have wanted to check the pressure and will do so the way you showed. Where do I get one of those fancy quick connect pressure gauges?

Tractor supply has the gauge and fittings.