D8R hot trans?

[Nige]

Sorry, I don’t agree with him. If you stall the tilt and are only getting 700psi instead of 3650 or something similar that the specification says then the pressure you are measuring is way low. Even though on the face of it the ripper and tilt functions appear to be less affected than the blade lift that doesn’t mean they are working 100% as they should. You are measuring a pressure that is only 20% of what it ought to be. That ain’t right.

 

[Robert0769]

Sorry, I don’t agree with him. If you stall the tilt and are only getting 700psi instead of 3650 or something similar that the specification says then the pressure you are measuring is way low. Even though on the face of it the ripper and tilt functions appear to be less affected than the blade lift that doesn’t mean they are working 100% as they should. You are measuring a pressure that is only 20% of what it ought to be. That ain’t right.

So the pump must be rebuilt or replaced?

 

[Nige]

Only if that is what the problem is. Right now all we know is that the pump is not developing the amount of pressure that it should do. The implement pump is a variable piston type (read the 2nd attachment above) and has a hydraulic control circuit that effectively tells it when to perform. If that control circuit is not functioning as it should then the pump will not work correctly even if there is no problem actually inside the pump itself.

 

[Robert0769]

John C has been following this thread. Here is the Hydraulic System & Implement Pump SysOp. Somehow I get the feeling that the pump is not upstroking when blade lift is called for.

What is the fix/test to see if it is upstroking?

 

[Nige]

I'll have to download the complete pump performance testing procedure. It'l be tomorrow.
When you see the procedure your first thought may be that you'll probably want to get someone in to do the work. It will be much more complex than what you have tested so far and require a large-ish number of different guages, one of which I'm fairly sure will be a differential pressure gauge.

 

[Robert0769]

I'll have to download the complete pump performance testing procedure. It'l be tomorrow.
When you see the procedure your first thought may be that you'll probably want to get someone in to do the work. It will be much more complex than what you have tested so far and require a large-ish number of different guages, one of which I'm fairly sure will be a differential pressure gauge.

Sounds good. So it looks like I need to have the main control valve taken out and torn down/looked at. Is the main control valve what the level directly connects to that's sitting on top of the pump?

 

[kshansen]

What did you get for a quick coupler..? The Cat Part Number is 6V-4144. The inside diameter of the coupler in the RH photo should be about the same diameter as the outside diameter of the machine test point in the LH photo. If that is not the case you were sold an incorrect coupler.
View attachment 200166View attachment 200167

Nige, I see I must have given the wrong information on the coupler.

I have spent a good amount of time trying to find information on the couplers and adapters but seem to be going in circles. I did find one place that referred to the 187-3546 coupler and it seems to indicate that is a coupler of pressures up to 8,700psi So I'm thinking Cat uses two different coupler systems based on the maximum pressures being tested.

Is there a reference paper somewhere that puts all this in one place? Would also be handy to have a listing of the fittings the couplers mate with giving the thread types and sizes.

To Robert0769, I apologize for giving the wrong information

 

[Robert0769]

Nige, I see I must have given the wrong information on the coupler.

I have spent a good amount of time trying to find information on the couplers and adapters but seem to be going in circles. I did find one place that referred to the 187-3546 coupler and it seems to indicate that is a coupler of pressures up to 8,700psi So I'm thinking Cat uses two different coupler systems based on the maximum pressures being tested.

Is there a reference paper somewhere that puts all this in one place? Would also be handy to have a listing of the fittings the couplers mate with giving the thread types and sizes.

To Robert0769, I apologize for giving the wrong information

No problem at all, it led to the right information! I appreciate all the help

 

[Robert0769]

By the way, I drained all the oil in the trans and torque converter today and it only drained 15 gallons total. Then 15 gallons to fill. I asked cat if it all drains from the rear screen and they said yes.. but then they tell me it takes 45 gallons. Little strangeness there I wanted to report. Kinda makes me feel like I'm nuts

 

[walkerv]

By the way, I drained all the oil in the trans and torque converter today and it only drained 15 gallons total. Then 15 gallons to fill. I asked cat if it all drains from the rear screen and they said yes.. but then they tell me it takes 45 gallons. Little strangeness there I wanted to report. Kinda makes me feel like I'm nuts

You missed something for sure if you only got 15 gallons out. Did you drain the main tranny case from the big plugg directly under the machine

 

[John C.]

That schematic is wonderful.

Testing to the pump means you have to read two pressures at the same time. You will need output pressure on the pump plus load sense pressure going back to the pump. Pump pressure should but around 300 PSI higher than the load sense pressure. If the difference is there you have a pump problem. If there is no difference, then you have a problem somewhere else. Since you haven't done it before and are having problems interpreting what we are getting at, I would suggest getting someone with experience to help you.

As far as the pressure tests go, did you check pressure on the ripper circuit as well? I see that implement pump also supplies charge pressure to the steering pump. Out of curiosity, how did the steering work for you?

 

[Mark250]

Could you perform this check please. it is a simple test of the resolver system that controls the pump out put

warm machine hydraulic system
engine at high idle
hold lift lever to full lift position
while holding lift lever operate tilt control both ways
while holding lift lever operate ripper control both ways
while holding lift lever operate the steering control both ways
if in one of these positions the blade lifts, you may have a faulty resolver on that circuit

John
I see that implement pump also supplies charge pressure to the steering pump. Out of curiosity, how did the steering work for you?
The implement pump only supplies charge oil to the steering system when the steering system charge oil is below approximately 290 psi

Mark

 

[Nige]

I think sleeping on it overnight was the key. I may have hit the jackpot. There IS a bleeding procedure for the implement signal circuit, but it's hidden away in the Testing & Adjusting section and quite frankly I only came across it by accident while reading through a 60-page document. I must be sad...…..

First, let's get oriented. Below is a couple of views of the implement pump. The pump pressure control valve is circled in the two views. I'm not sure which of the two views relate to the way the pump is installed in the tractor so I included both of them. The valve may be on top of the pump, it may be on the side.

 

[Nige]

Next, here is a closer look at the pump control valve. The bleed screw #18 is circled.



The bleeding procedure is: -
1. Stop the engine. Wiggle all the control levers (lift, tilt, ripper) to release any pressure in the system.
2. Unscrew the bleed screw 3 turns ONLY. (Will require a metric Allen Key to fit the plug)
3. Start the engine and run at LOW IDLE ONLY. A small amount of oil may come out of the bleed screw during the procedure.
The following steps may cause the implements to move. Be prepared for that and ensure that people keep well away from them.
4. Move the blade tilt control lever to full tilt in one direction for 5 seconds then return it to neutral.
5. Move the blade tilt control lever to full tilt in the other direction for 5 seconds then return it to neutral.
6. Repeat steps 4 & 5 for the Blade Lift control lever.
7. Repeat Steps 4 & 5 for the Ripper control lever.
8. Close the purge valve before stopping the engine.
NOTE: It is important to perform the procedure in the order of Tilt->Ripper->Lift because it starts at the cover end of the implement control valve and works to the other end. Performing the procedure in any other order is not guaranteed to get all the air out of the implement signal circuit.

 

[Mark250]

Here is a photo of the pump position on the machine

 

[Nige]

Mark, is that the bleed screw that I've circled..?

 

[nicky 68a]

Robert,when my D8R implement pump failed,the ripper and steering seemed perfect,however it was stopped immediately.
If I recall,the tank and lines were drained as best as possible and all filters removed.We also took part of the tank apart to remove any debris.
In fairness,the filter and tank were clean but we still used clean up filters for the first day or so.
The pump itself was fed with oil as well prior to firing up the engine.I wasn't present to see it bled,but it's worked for 3 years since.I have changed the hyd oil on it myself a few days after the fault,but I genuinely can't remember any problems with bleeding the system.
I think I just let it idle and operate the blade and ripper with the filler cap off?
For the record,there was just one of the 4 valve chambers at fault,so I got 2.5k of my 5k back a month later.

 

[Robert0769]

A lot of good things to try now.

The pressure from the pump was 700 for tilt, lift and ripper.

The only way to get the blade up is to pull up and tilt at the same time.

The blade does slowly go up in reverse but not forward.

I did not do any steering while looking at the gauge. I will do so.

I do have a question, picture number 1 is the side view of a pump I've been testing at Port A.. and picture number 2 is the top view of the main valve I believe. Am I correct so far?

So where is the main implement pump? Is the implement pump picture number 1?

 

[Robert0769]

You missed something for sure if you only got 15 gallons out. Did you drain the main tranny case from the big plugg directly under the machine

I did not, Cat said no need to touch it since the rear screen housing drains it all. Much more knowledgeable here it seems. I mean I asked them for the main valve body rebuild kit and they refused and said my only options with them are a new one or rebuilt one, they will not sell or make a list of parts for me to rebuild myself

 

[Nige]

If you follow the lines from the Test Ports A and B backwards it will lead you to the implement pump.
Sounds like you need a Parts Manual