[FredM]

This may help if you don't already have it.

 

[FredM]

Thank you FredM. I looked at the download and as I've heard the DB 3 point is a complicated system, and I agree, it looks very hard to understand. Not sure where I'm going from here. Hopefully someone will chime in with some ideas where I should start and what to check for.

At the top of the first page, this explains the reason for the cable connected to the top link mount!!.

Figure 178 shows info for the by-pass valve and hold valve, this has a nylon screen which can be cleaned, and figure 236 gives you trouble shooting.

I would pull the cover as described in fig.178 and remove the by-pass valve and check the nylon screen and the plunger, read fig.227, important that these valves are working.

You can pull the main control valve and clean plungers etc., but don't change any settings, otherwise you will have trouble, the system looks complicated, so some reading is required to understand it, it is a good system.

When the system was working and carrying a load on the 3 points, did the 3 points sink at all, slowly or reasonably quick??.

 

[FredM]

With the very heavy 7ft John Deere back blade on it, I could have it in the up position (engine running) it would drift down maybe 1/2 inch (over a 1-2 min period) then you could hear it kick back in and go back up to the original height.

I am going to take a stab at your problem, you mention the remote hydraulics have pressure, so the pump and pressure relief valve appear to be working, because of the age of the tractor, I would say the ram piston seals have finally failed.

In the first photo there is an oval plate held in place by 2 phillip head screws just in front of the selectamatic lever, the by-pass and hold valves are under that plate and it is an easy job to pull them to check, each has a slot head threaded plug over the valves, just a matter of unscrewing and removing the valves, one has the nylon filter incorporated in the valve which needs to be checked occasionally.

You could try shifting the selectamatic lever to TCU position, to do this always pull the raise/lower lever to the most rearward position against spring pressure, for that matter always pull the lever against spring pressure when shifting the selectamatic lever,-- when in TCU position, from memory the raise/lower lever works the opposite, push forward to raise and pull back to lower, you could try that and see if the 3 point works, most tiomes the selectamatic lever is set in the height position.

 

[FredM]

It is quite obvious you are not reading any info in the PDF I sent you, in my post #5 I explained what the two valves were under the cover you are asking about in your third photo.

All of the valves used in the hydraulic system on the DB's are contained in the control valve, I have attached a reference to those , and this is from the PDF.

The object in your second photo I would say is an oil transfer port, of the 3 DB's I looked after from the mid 60's to early 90's, this was a part that was never touched, but I will try and find some info for you, this cover you ask about is the oil supply to the lift cylinder, the lift cylinder is in that housing, there is either a 3/8" or 1/2" BSP plug there above the transfer port that you could remove and plug in a pressure gauge to get a reading.

But do sit down and read the PDF.

 

[FredM]

FredM.....Sorry. I did read through it but that is a lot of information for an old 75 year of man. I will read it again.

My apologies for being a little blunt, and I agree with you, that PDF is heavy reading and a lot to take in, and I am also sorry that I cannot help you with more info, I am 87, but I try my best, an old saying I live by now "I have forgotten more that I can remember".

Do pull those 2 valves I have mentioned, both are important in the operation of the system, if you read the center column in the blue Attachment, this explains what you need to do and be careful of.

 

[FredM]

Messicks have a parts breakdown of the DB's, this is just one section, shows it wont take much to remove the rockshaft to replace the ram piston seals.

Case IH 880 - DAVID BROWN IMPLEMATIC TRACTOR(01/60 - 12/65) Parts Diagrams

Case IH Parts Catalog Lookup. Buy Case IH Parts Online & Save!

www.messicks.com

 

[FredM]

I wish you were here too.

Terry!!, it would be so much easier to fathom out problems if we were there, but!!.

 

[FredM]

Forgot to mention. The one valve I cleaned was the one closest to the rear tire.

That is called the "by-pass valve" Terry, that is good to hear you are go again.