# IH 3400A MCV Pump Checks



## etemplet (May 6, 2012)

My steering issues may be the result of an MCV pump failure but I don't want to replace something that is good and especially I don't want to do extra work. I've spent a few days under this thing in the past week and I'd like to get some closure.

I had some issues with the speed of the loader as well which... is probably a sign that the MCV pump is not healthy since the MCV pump adds additional flow to the loader. It sure would be nice to have one of those nifty hydraulic testing tools shown in the owners manual. Helpful it would be for certain.

Input would be appreciated. Thanks,


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## sixbales (May 18, 2011)

A simple check to make is a pressure test on the pump. You need to use a 3000 psi gauge, and the pressure should exceed 2000 psi. A shop or service manual will show you where to install the gauge.


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## etemplet (May 6, 2012)

Hopefully a leaking RV doesn't give me a false reading but I did visually inspect both the RV and the Diverter valve. What i did not check is the system RV. As I read about it, it seemed to be for a 3-point hitch connection. I also did not find any orings... I may need to pull this unit just to do a good inspection and rebuild. Thanks again for the input.


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## etemplet (May 6, 2012)

Picture of my MCV Valve and Pump

Found some sludge around the system relief Valve. This is one area I did not check prior to pulling the MCV. I thought this was part of a PTO 3 point hitch system which I do not have.

The second picture is of the MCV Pump Internal. I'm not sure how much this wear is affecting pumping capacity. The Third picture is of the pump gears. There is some wear between the gears and again, I am not sure to what degree this is affecting the pump output.

The 4th picture is of the MCV valve gasket area and again you can see the sludge. In put is appreciated.


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## etemplet (May 6, 2012)

I need some help identifying what this IPTO thing is on my MCV valve. It moves up and down freely but darn if I know what it is supposed to do. Is this another 3 point hitch item ?? 

I am also curious as to the purpose of this large dome on the MCV. Is there suppose to be a filter in this area. I did not clean the sealing area yet but I would expect to find an O-ring in there which.. I did not see off hand. However there were no leaks on the pump


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## BigT (Sep 15, 2014)

From the second picture, that pump appears to be "scored" badly. If so, you have metal particulate throughout the system. How did the pressure test go? Does the pump put out 2000+ psi?


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## etemplet (May 6, 2012)

BigT said:


> From the second picture, that pump appears to be "scored" badly. If so, you have metal particulate throughout the system. How did the pressure test go? Does the pump put out 2000+ psi?


BigT I didn't pressure test anything. System performance was non-existent so I figured it best to start with the pump and valving. This hoe was in horrible shape when I purchased it. I don't know how old the pump is but it looks like someone had been in there previously to me.

I want to do a good repair on this section so it performs as designed or close to it. What I am looking for is some affirmation that the wear associated could be at least a contributor to the steering issues. I plan to check much of the hydraulic system as a result of theoil contamination.

Question. Is there suppose to be some type of filter in the dome of the MCV valve ? Looks like they have room there for one. Thanks for the input,


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## BigT (Sep 15, 2014)

IMO, the first thing you should check is the pump pressure. If the pump isn't working, that's your first problem. If you have metal particulate matter throughout the system, you are likely to be looking at a major headache and expense. You might want to consider cutting your losses with this tractor. Just my two cents worth. 

Click on the Messick's ad on top of the page. They have parts diagrams for your tractor, which will hopefully answer your questions.


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## etemplet (May 6, 2012)

Thanks. The backhoe isn't that bad off. I've been though most of the systems and the look pretty darn good. It is difficult to find knowledgeable people in regard to this old equipment. Sure looks to me like an oil filter inside that big dome would be the thing to have but... guess not. LOL

I did my due diligence on troubleshooting. The pump is bad and lots of things can cause that type of failure, cavitation being the most obvious but a bad relief valve, incorrect or degraded emulsified fluid etc... I am going to replace the pump but I want to do the system up right and get it back up to speed.

Thanks for the suggestions. I will follow up.


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## TraderMark (Nov 15, 2011)

There doesn't appear to be a filter under the dome. It looks like the filter is externally mounted according to the diagram at the Case/IH website. I'll try and attach the diagram here.

Mark


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## etemplet (May 6, 2012)

TraderMark.... that is good stuff right there. I need the part number for the hydraulic filter in the canister.

I was just wondering about the suction inlet for the MCV because it looked quite large and round. You know the modifications made to these machines and parts left out over the years. I was curious Thanks for the input.

I need to find that Website and how to use it properly. I could use some pictures with part numbers and a good parts supplier.

Thanks again !!


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## TraderMark (Nov 15, 2011)

Here's the exploded view of the filter itself.


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## BigT (Sep 15, 2014)

Hey Mark,

How did you get that diagram? I entered "3400A", "3400" and got no results for this tractor.


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## etemplet (May 6, 2012)

Great stuff Mark. My canister is broken internally which does not allow the filter to seat properly. I am trying to determine the correct filter so I can make repairs that will be appropriate. These old machines have seen lots of mechanics or so called mechanics work on them and things get done the wrong way.

I hope the part number is something the sellers can identify so I can get started solving the problem.


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## TraderMark (Nov 15, 2011)

Gene,
The first time I went to the site I just typed in 3400 and the first result was "3400 series A International"

Subsequent trips to the same site I had to type in "#3400 series A" to get the IH tractor to come up.

Mark


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## TraderMark (Nov 15, 2011)

The hydraulic filter should interchange to NAPA FIL1493.


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## etemplet (May 6, 2012)

TraderMark said:


> The hydraulic filter should interchange to NAPA FIL1493.


Thanks, I got that one on order. Whew.... you are a fantastic help. At least now I can begin. Yay !!


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## etemplet (May 6, 2012)

TraderMark said:


> Gene,
> The first time I went to the site I just typed in 3400 and the first result was "3400 series A International"
> 
> Subsequent trips to the same site I had to type in "#3400 series A" to get the IH tractor to come up.
> ...


Thanks again Mark. When I typed in "3400 series A" I was able to access a file I could download. I kept getting an error and it would not work when I tried it the other way.

Even better !!!


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## etemplet (May 6, 2012)

Well tradermark, my parts book arrived today. I ordered it the day before you showed me how to access the site for parts. LOL I ordered a new MCV Pump and gaskets. I disassembled all but the IPTO valve. I replaced a couple of o-rings and did lot of cleaning and looking around. The pump is installed and at present I am straightening out significant bends and kinks in the piping. Hopefully, I'll get some fluid in there and giver her a try today.... maybe.


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## TraderMark (Nov 15, 2011)

Good luck Gene!
Keep us posted on the progress.

A little tip on straightening metal hydraulic lines. ...... Use a soft rubber hammer against a block of wood. The line will bend but the rubber hammer won't squash it flat. I've bent many a kink out of a metal line this way.

Mark


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## etemplet (May 6, 2012)

Thanks Mark. I heated the lines up, made an internal rod that would do the job and pushed the kinks out from the inside. I was concerned about possible cavitation and I a quite happy with the result. Took some time and patience but Gpt R done.

I have yet to fill the hydraulic system so.... we'll see how well I did.  

Thanks for all th help !!


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## etemplet (May 6, 2012)

Well.... ahhhhhh...... Hydraulics are working like a champ. Bucket is powerful and AMEN the steering is easy peazy on the finger.


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## TraderMark (Nov 15, 2011)

Don't ya love it when a plan finally starts to come together??


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## etemplet (May 6, 2012)

TraderMark said:


> Don't ya love it when a plan finally starts to come together??


It feels good for sure but there is much left to do. I just can't leave things not working properly.


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## TraderMark (Nov 15, 2011)

Oh I know the feeling!! LOML says I am WAY too anal how things work and look with my tractors and equipment. LOL


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