D8R hot trans?

[Nige]

I understand where you're going with this, but here's my 2c.

The screen should go back into the converter suction as soon as practical, but at the same time I would also be looking at where contamination could be entering the transmission/converter hydraulic system. You remember that we spoke about the breather for the power train system earlier (9G-5127 - Post #36 on Page 2). I would replace that, make sure that locations such as the power train oil filler cap and the dipstick were not letting dirt in, etc. I'd do all that before even thinking about changing the oil again. I would do all the other stuff to make sure that nothing could get into the transmission oil system that shouldn't be there. If you can't keep contamination out what's the point of changing the oil..? I recall that you reconnected the wires on the transmission filter housing. Is it still throwing warnings for plugged filters..? If changing the filter makes the light go out, keep changing them, it means that the filter is pulling contamination out of the system IMHO.

For the hydraulic oil I would replace the 191-5439 breaker relief valve on the hydraulic tank (again, dirt can get in there) sample the oil and change the filter every 250 hours, and see how the oil analysis goes.

One of the most important factors to consider when you send off oil samples is to make sure that all the necessary information is completed on the form that accompanies the oil sample. Without that info any lab would be struggling to make a good interpretation of the analysis: -
1. Oil changed - Y/N.?
2. Filter changed - Y/N.?
3. Operating Hours on oil..?
4. Approx. quantity of oil added since the last sample was taken.

 

[Robert0769]

I understand where you're going with this, but here's my 2c.

The screen should go back into the converter suction as soon as practical, but at the same time I would also be looking at where contamination could be entering the transmission/converter hydraulic system. You remember that we spoke about the breather for the power train system earlier (9G-5127 - Post #36 on Page 2). I would replace that, make sure that locations such as the power train oil filler cap and the dipstick were not letting dirt in, etc. I'd do all that before even thinking about changing the oil again. I would do all the other stuff to make sure that nothing could get into the transmission oil system that shouldn't be there. If you can't keep contamination out what's the point of changing the oil..? I recall that you reconnected the wires on the transmission filter housing. Is it still throwing warnings for plugged filters..? If changing the filter makes the light go out, keep changing them, it means that the filter is pulling contamination out of the system IMHO.

For the hydraulic oil I would replace the 191-5439 breaker relief valve on the hydraulic tank (again, dirt can get in there) sample the oil and change the filter every 250 hours, and see how the oil analysis goes.

One of the most important factors to consider when you send off oil samples is to make sure that all the necessary information is completed on the form that accompanies the oil sample. Without that info any lab would be struggling to make a good interpretation of the analysis: -
1. Oil changed - Y/N.?
2. Filter changed - Y/N.?
3. Operating Hours on oil..?
4. Approx. quantity of oil added since the last sample was taken.

I understand. When I reconnected the powertrain filter wires it would blink the bypass light at medium to high rev. Then I put in that wrong filter they gave me which would still blink at medium to high rev. I then replaced that filter with the correct filter the next day and it has not given a bypass light since so I guess it isn't that dirty.

I'm going to get the picture of the spot for the trans breather today. I think the Cat tech was wrong in saying it looks like something else.

I'm going to order the hydraulic valve today as well. There is lots of dirt in the valve.

I'm going to buy a fuel gauge for the tank I fill from so I can start keeping track of how many gallons I actually put in each day and how much engine oil I add each day.

I know the dozer came from a pipe job in Canada so maybe it was in higher elevation? The next 250 hours will answer a lot of questions with the next sos sample.

 

[Nige]

I'm going to order the hydraulic valve today as well. There is lots of dirt in the valve.

Are you talking about the Quick Drop valve on top of the hood..? Post some photos before you go buying a valve. It may be it just needs cleaning, and probably the rest of the hydraulic system might need a bit of an internal spring-clean as well

 

[Robert0769]

Are you talking about the Quick Drop valve on top of the hood..? Post some photos before you go buying a valve. It may be it just needs cleaning, and probably the rest of the hydraulic system might need a bit of an internal spring-clean as well

No was talking about the pressure valve on top of the hydraulic tank. I can blow/suck air and it has dirt in it.

I opened the quick drop valve, 100% clean. Spring looked great. Wasn't stuck depressed. The other side, plunger side I guess, I could push it in and out easily and hear the fluid moving in the ram. Looks like it is working properly

 

[Nige]

Sorry, I misunderstood you.
So we know the quick drop valve isn't the cause of the problem. I don't know how far you want to dig into the system but try this as a suggestion to check for internal blade lift cylinder leakage.

1. Remove the tin covers #1 on the top of both lift cylinders.
2. Pull the pins & disconnect both blade lift cylinders from the blade.
3. Retract both cylinders so that the rods are retracted inside the barrel and they don't move any further. See if you can't put a sling or something on each one to prevent it from floating down.
4. On both cylinders loosen (DO NOT REMOVE) the hose connection under the tin coverthat is circled. That is the return line when the cylinder is moving upwards.
5. Start the machine, set the engine to High Idle and slowly move the blade control as though you are trying to raise the blade. Observe the loosened connections, are you getting a steady flow of oil out of one or the other cylinder, or even both..? If you are the cylinders are leaking internally and appear as though they need resealing.

 

[Robert0769]

Sorry, I misunderstood you.
So we know the quick drop valve isn't the cause of the problem. I don't know how far you want to dig into the system but try this as a suggestion to check for internal blade lift cylinder leakage.

1. Remove the tin covers #1 on the top of both lift cylinders.
2. Pull the pins & disconnect both blade lift cylinders from the blade.
3. Retract both cylinders so that the rods are retracted inside the barrel and they don't move any further. See if you can't put a sling or something on each one to prevent it from floating down.
4. On both cylinders loosen (DO NOT REMOVE) the hose connection under the tin coverthat is circled. That is the return line when the cylinder is moving upwards.
5. Start the machine, set the engine to High Idle and slowly move the blade control as though you are trying to raise the blade. Observe the loosened connections, are you getting a steady flow of oil out of one or the other cylinder, or even both..? If you are the cylinders are leaking internally and appear as though they need resealing.

View attachment 199679View attachment 199680

Sounds good, I'll get it done. I should have a pressure test today as well. I believe you sent a diagram on another reply for which part to hook the gauge up to for lifting the blade?

 

[Robert0769]

Sorry, I misunderstood you.
So we know the quick drop valve isn't the cause of the problem. I don't know how far you want to dig into the system but try this as a suggestion to check for internal blade lift cylinder leakage.

1. Remove the tin covers #1 on the top of both lift cylinders.
2. Pull the pins & disconnect both blade lift cylinders from the blade.
3. Retract both cylinders so that the rods are retracted inside the barrel and they don't move any further. See if you can't put a sling or something on each one to prevent it from floating down.
4. On both cylinders loosen (DO NOT REMOVE) the hose connection under the tin coverthat is circled. That is the return line when the cylinder is moving upwards.
5. Start the machine, set the engine to High Idle and slowly move the blade control as though you are trying to raise the blade. Observe the loosened connections, are you getting a steady flow of oil out of one or the other cylinder, or even both..? If you are the cylinders are leaking internally and appear as though they need resealing.

View attachment 199679View attachment 199680

I'm going to get a pressure gauge. To make sure I get the right one, is 0-290psi good? I don't think the pressures should be over 60, correct?

 

[Nige]

Personally I would do the cylinder line leak test first. Remember that to test pump pressure the operator seat and the cab floor both have to be removed .
You will need a 5000 or 6000psi gauge. The specified pressure is 3500 +/-65psi on Test Point A below. Procedure is as follows: -
1. With the engine at HIGH IDLE, move the bulldozer blade tilt lever to the maximum TILT LEFT or TILT RIGHT position. After the cylinder is at the end of the stroke, the implement pump is at the stall condition.
2. The pressure reading should be 3500 ± 65 psi. Note: Do not hold the machine in the implement stall condition for more than 15 seconds at a time. Wait 1 to 2 minutes before going back to the stall condition.

 

[Robert0769]

Personally I would do the cylinder line leak test first. Remember that to test pump pressure the operator seat and the cab floor both have to be removed .
You will need a 5000 or 6000psi gauge. The specified pressure is 3500 +/-65psi on Test Point A below. Procedure is as follows: -
1. With the engine at HIGH IDLE, move the bulldozer blade tilt lever to the maximum TILT LEFT or TILT RIGHT position. After the cylinder is at the end of the stroke, the implement pump is at the stall condition.
2. The pressure reading should be 3500 ± 65 psi. Note: Do not hold the machine in the implement stall condition for more than 15 seconds at a time. Wait 1 to 2 minutes before going back to the stall condition.

View attachment 199682

Just curious, why does the pressure test for the two front lift cylinders require tilting of the blade to test? There is a separate third smaller cylinder on the right side of the blade arm that does the tilting.

I figured you would put the gauge on the pump then pull back to lift?

 

[Nige]

The main implement (hydraulic) pump supplies oil for all the functions. Blade lift, blade tilt, ripper (if equipped). To a certain extent it doesn't matter which function you move, but the presence of the QD valve on the blade lift circuit could be sufficient to skew the results. The accepted form of testing pressure a tractor implement pump is to use the blade tilt circuit.

 

[John C.]

Blade lift has topping valves that open when the pistons reach the end of their stroke. They allow oil to bypass through the pistons so they don't impact on the ends of the cylinder barrels.
I do seem to recall a separate pump for the rippers though. I think it was piggy backed on the main pump. That could be model specific though.

 

[Robert0769]

The main implement (hydraulic) pump supplies oil for all the functions. Blade lift, blade tilt, ripper (if equipped). To a certain extent it doesn't matter which function you move, but the presence of the QD valve on the blade lift circuit could be sufficient to skew the results. The accepted form of testing pressure a tractor implement pump is to use the blade tilt circuit.

First picture is where I believe the trans breather goes? It just has some thing with a hole in it. Is this the right spot? Second picture is the trans breather.

Third picture is the pump and fourth is the gauge. The gauge doesn't match the connections on the pump. I asked cat if they're the same and they said yes. Going to call them now.

Are the two rounded spots on the pump where I hook up to? Is that the correct trans breather location?

Also I did the Piston test, I had them fully in, with connections cracked. I pulled back for up and at first nothing then oil started leaking faster after a while, seemed like it wasn't getting pressure at first then started to

 

[Robert0769]

So I got a good look at the trans breather now. It's just completely missing the breather and the little adapter that goes with it. Will go back for the adapter.

The gauge is the wrong gauge, they say I need a different one that's $1,000. I think I'll try to find an adapter for this one or something

 

[kshansen]

If that gauge is for the pressure range you want to measure I say BS on the dealer.

I'm going to assume you want to check pressures a the two point with the red arrows in the picture below.

If that is where you need to hook up the gauge you need one of the 187-3546 Couplers from Cat at about $56.00 and a hose to connect the coupler to the gauge. The hose could be purchased any place that make hydraulic hoses as long as the know what pressures you will be measuring.

 

[Robert0769]

If that gauge is for the pressure range you want to measure I say BS on the dealer.

I'm going to assume you want to check pressures a the two point with the red arrows in the picture below.
View attachment 199828
If that is where you need to hook up the gauge you need one of the 187-3546 Couplers from Cat at about $56.00 and a hose to connect the coupler to the gauge. The hose could be purchased any place that make hydraulic hoses as long as the know what pressures you will be measuring.

Awesome thank you. I'll get that part, get a hose and test the pressure. Yes those are the spots I'd like to hook up to. Looks like those are quick connect parts that can be taken off and possibly use the gauge I have but I'd rather get the hose and connection.

 

[John C.]

You can get the coupler and hose along with any pressure range gauge you might need for far less money than a Cat dealer wants to charge you at most any hydraulic supply house. Spencer hydraulics and Motion & Flow Control Products. Inc are two good suppliers that I believe are nation wide.

 

[kshansen]

And it might be a good idea to get new rubber covers to keep the dirt out of the fittings. I might be able to get the Cat numbers or the place John C suggest might also have them at a better price.

 

[Nige]

Dust Caps are Part Number 6V-0852. $4 each from Cat.

Talking about your trans breather. You have something missing from the machine. See below. I believe that the hose in your photo is Ref #41. You can confirm that by checking the Part Number on the aluminium tag about 2" down the hose. Is it 9U-8249..? If that hose is open you have dust falling straight into that opening and ending up in your power train oil system.
See the sketch below. There should be a tee that connects into a tank (maybe), the illustration is not 100% clear and I'm not there at the machine. I think you are missing items 38, 39, 40, 42, & 43. You have a new breather 44 and you have the end of the hose 41. It just need to be determined exactly where the tee #39 actually installs. There must be a connection very close to the end of that loose hose shown in your photo with (I would hope) a plug in it.

 

[d9gdon]

Good long distance catch, Nige.

 

[kshansen]

Yes would be handy to know what that tag says in the image that ends with 8226-JPG

Here is what SIS shows for the location of the transmission breather: