Added a hydraulic filter in return line from FEL

[koppel]

Hi All,

I have just finished fitting a second hand FEL to my B7100HST.

One of the many things very average on this FEL was the state of the hydraulic rams.

The rods were rusted and chrome was pitted. Mind you not to badly, so I dismantled the 4 rams, cleaned them, polished the rods in my lathe; then reassembled them with new seals.

The hydraulic oil for the loader shares the same oil resevoir as the Hydrostatic transmisson, so I did not wish to have any possible contamination from these second hand rams and piping get back into the HST transmission sump.

Solution:- I came up with, was to fit a high pressure filter in the return line from the FEL hydraulics.

A quick ring around the hydraulic supplier outlets located a suitable unit.
Suitable in size and cost of both the body and the replacement elements.

Its made by OMT (( http://www.omtfiltri.com )) and is MHP220ANR. (( http://www.omtfiltri.com/english/downloads/filters.htm))

I choose the one with built in bypass valve, since the port on my B7100 is directly off the pump outlet; and before the main hydraulic relief valve. That way if the filter blocks badly I would not blow a hydraulic line or have the guts of filter enter my HST.

The one I got is good for up to 6 litres per minute at a max pressure of 280 bar.
I choose the 10 micron filter element. Available elements range from 10 to 125 microns. Had my rams been new I would have opted for a less fine element than I did.

Thats a good set of specs for what I needed.

It was easy to fit as you can see in the pic. I think later i will add a flexible support strap to the top filter body mounting hole; as the unit is somewhat heavy.

Hope at least one on this great site finds this a worth while addition to their tractor.

My loader is not being worked hard so the flow rate restriction this filter may add is not an issue.

I will add some more pics of my loader in due course.

regards
david

 

[maximus]

Hi David,

Great idea - as you say most rams on the older FELs are in bad condition. Great picture.

I see you have connected the filter directly into the integration block. Have you had any problems with the block - such as leakage? I've got a spare block and thinking I might add it into the steel line (my B7000 doesn't have the block as it wasn't added during manufacture). The alternative is just to cut the line and add male connectors to both cut ends. Does the block screw into the tractor body, or is it just supported by the pipework? Just thinking, that, if I screw the block into the tractor body the connections are going to be more secure, than just loose cut ends - if you get my meaning.

Cheers


Chris

 

[dookanooka]

hi Maximus,
you got there before me! Except I was going to ask what that rectangular block was, and then ask whether it would be easier to use than brazing on male fittings. If however it just comes fitted on certain B7000's, then maybe that answer's not so easy It looks like a good thing to use on my B6000 to get hydraulic power to a new FEL i'm attaching though. Where did you get your spare from and is there a part number for it?

Koppel,
that's a great idea using a filter, I shall look into getting one. I'm wondering whether i'd increase the micron size of the filter to ensure more flow though, but then I intend to get new cylinders...if I find one's that fit!

 

[koppel]

Hi to you both.

well Cris and dookanooka the grey part of the block in photo was origional on my B7100.

Its steel.

The bright part the filter is screwed into is Aluminium.

There are 2 different ones of these Al blocks.

One has a cross drilling (end to end) and no outlet holes (on front) to screw in hydraulic hose fittings to feed oil to and from the FEL rams.

The second type has NO cross drilling just 2 holes front to rear. The front side of the holes are tapped to take hydraulic threaded fitting. If I recall 3/8 BSPP. ( the ones that use rear seal ring and nut. Dont use Taper threaded fitting.

No chris I have not had any leaks so far. I used new O rings and hydraulic pipe thread sealant.. NOT thread tape.

As to cutting your existing steel line from pump outlet to rear of tractor and "Brasing in a new steel block that would be easy. Except for 2 got yas.

1. You will need to make sure of the alignment of the pipes in and out when you braze the 2 cut pieces into each end of the steel block. Simple way that going to be close enough is to lightly scribe a straight line with a steel scribe along one side ( outer is best) on the centre line of the tube for about 2" past each end of the section your going to cut out. When you make the steel block ( or buy it) then you can scribe a line on each end in the same place and match lines on pipe up. Hope you followed that.

2 The second problem and the bigger one is after cutting your existing pipe is to find a way to best clean it inside PRE and POST brazing. Both are equally important steps.

If you dont remove all the oil then the heat from brazing with end up creating burnt oil resedue in pipe that will be a real problem to remove.

Also after brazing you really should "pickle" the pipes inner and remove and scale the brazing heat will have caused. Also will remove any welding flux that may have entered the pipe.

In my opinion I would stick with cutting out a section with fine hacksaw and use high pressure hydraulic pipe to hose fitting to make the connection.

You should only need a pair of right angle ones.

Hope that helps.

Ask if you need more comments

regards
david