1830 jd Hydraulic

[Farmer1]

Looking for some help with recently overhauled hydraulics by dealer on 1830. New transmission pump and main pump. I am trying to diagnose myself and here is what I have come up with. I have 3.75- 4 gpm from transmission pump taken at oil cooler @ 100psi or 125 psi restricted. I have tried bypassing shift cover by looping charge lines under cover and I still get same flow. Transmission pump is new as well as oil lines. Any ideas. Is it possible for steering to work great and still have an internal leak in it which is bleeding off my oil. Book says I need 6 gpm. Any other places I should check for leakage?

 

[buickanddeere]

Sounds like they were guessing and threw parts at the tractor. Odds are 99% the trans and front pump were ok.
There are trans oil relief and divert valves. Likly one of them are stuck or bypassing flow.
Possibly some restriction in a suction or pressure line.
Probably going to be a $9.99 part failure that was missed.

 

[Farmer1]

Is there anything to the relief valve. I pulled it out ad there is a spring and a ball both look okay. What is the divert valve. There is a flow control valve I think they call it that is beside hyd. filter that hooks to line coming from front. it was replaced I haven't rechcked it though.
I should mention the tractor didn't work good when I got it back and I set it aside for winter project. When I did look at it I found a rag in the sump screen, it was inside but I'm worried it could have made it somewhere in the system.

 

[44 Diesel Tech]

You do not say what the problem is. You stated your findings. At any rate, the one thing you should check (as B%D stated ) is the filter relief valve. Sometimes a piece of rubber from filter gets into valve holding it open. Are you losing steering and rockshaft operation? Are they slow? By the way, steering will still work good at cooler pressure as low as 10psi and flow of 2gpm.

 

[Farmer1]

The problem with the tractor is that the front end loader is slow and chatters some. Everything else works. The one thing I had to fight with was bleeding brakes. It took forever before they would finally bleed. They return and hold pressure when pushed though. There is I whining noise sometimes at the main pump when after I have had it reved up I rev it down. There isn't any oil flowing through the clear bleed line on main pump to resevoir is this normal?

 

[44 Diesel Tech]

No oil in plastic line is ok. That is a good thing. Now lets get to the loader, what make and model? What valve? How are the hoses plumbed to tractor? Have you got return to filter cover? One other thing,make sure your JD dealer installed the two hyd. lines correctly in front of trans. The inside line goes forward to cooler. The outside line is the one to the pump inlet.

 

[Farmer1]

The Loader is 145 jd. I'm not sure what you mean by what valve, but it has the two pull levers and a third mounted seperate for grapple hook. The loader is plumbed from valves to a tee at filter which also goes back to remotes and the other is at a fitting just below flow control valve. I don't have 3-point hitch. I don't know what return to filter cover is unless you mean where it hooks to the Tee. Could a problem with the loader cause leakage somehow in the charge system? The best I can get is 4GPM @100psi and book says I need 6 gpm. Also hyd. lines were plumbed right from trans to pump. The pump at front is an 8 piston.

 

[buickanddeere]

The divert valve will limit flow and eventually stop flow to the front pump. In order to maintain transmission lubrication and brakes.
This divert function usually happens as the trans filter becomes clogged.
That rag you found may well be the source of the problems floating around and jamming flow control somewhere.
Although that trans pump is about 6gpm,approx 2gpm goes to trans lubrication etc. Which makes your 4gpm about right.
This is why a Dubuque or Mannheim utility tractor requires the use of a ported filter cover. The undersized trans pump can not keep up with the front pump demand.
If I understand this correctly.The loader valves return oil into the trans oil filter cover. The loader is supplied direct from a high pressure oil line. Instead of the mickey mouse scv supply.All well and good.
I'm wondering if that 3rd add on valve for the grapple is open centered rather than closed centered?

 

[44 Diesel Tech]

It sounds like it's all hooked up right. Your loader is unlikely causing any problem with the charge supply oil. Another thing you could try is to beg borrow or steal a hyd. flow rator and hook it up to the loader valve. Remove the two hoses going to the boom cyl's and hook up the flow rator in place of them. Run engine at 2200 , pull boom lever back and restrict flow to get about 1750 psi. then read gpm. You should have smooth flow and no chatter. Note cooler pressure at this time which could be as low as 50lbs or as high as 110lbs. Note: When spool of valve is pushed in, you get flow out port farthest away from lever. Make sure this goes to inlet of flow rator.

 

[tractor fixer]

if the loader has a open or closed center plug i would check to see the condition of the spring holding the plug in closed position.

 

[Farmer1]

Thanks for the info. I have a flow meter and will try what you say. Shall I put a pressure gauge in at oil cooler to test it while I am metering loader or does oil need to flow back to tractor. It will be a few days before I can try this. It is -30 here for the next couple days. Also how is the best way to test flow control valve or is that not relevant to charge system?
Thanks for all of the info so far.

 

[Farmer1]

Where would this plug be? Before I had this tractor worked on I did have problems with the loader valves sticking on and sometimes would quit altogether and I would have to shut off tractor and move all remotes and loader levers and it seemed to snap it out of it once I started it. But that before they changed the trans pump and main pump.

 

[buickanddeere]

Simple test is to take the return lines from the valves and aim the open end of the hose into a pail or the hydraulic filler behind the seat.
Start the engine, if there is any flow while the valves are in the neutral position. There is a failed or wrong type valve.

 

[Farmer1]

I was wondering where the divert valve would be located? I hooked my flowmeter at output of oil storage tank to input gauge and output gauge to top of oil cooler is this the most accurate place to check?

 

[buickanddeere]

Anywhere on the line running from the transmission to the oil cooler/storage tank.
Mid way through the 40 series the Mannheim trans pump capacity was increased.
As long as the loader valves are closed center. And all loader oil returns to the ported filter cover. With the trans pump able to pump 4gpm. The front pump will never run out of oil even if pumping 20gpm.