Case DH4B Trencher/Backhoe Won't Spin Trenching Chain

[r8f1k]

Any thoughts on where to get a seal kit for my leaking cylinder? Below is the link to a kit, but no one has it in stock. I'm betting that most of the seals are generic, but any guidance on getting a kit would be ideal.

Manufactured by - CASE

H122234 Machine Parts from CASE 2-Year Warranty - SEAL KIT CYLINDER H

www.radwell.com

 

[laurencen]

for most of my rebuild kits I use HW partstore, had several times the Deere dealer price was 6 times what HW could supply, never had a issue with the quality or fit

Quality Construction Equipment Seal Kits & Repair Parts

HW Part Store is an organized and easy to navigate online store for Aftermarket Hydraulic Seal Kits & Replacement Parts for Case, Caterpillar, & John Deere Industrial Construction Equipment at Discount Prices.

hwpartstore.com

 

[Doaaj50]

Here are a couple of options for you:
Northern Tool
Discount Hydraulics

I would go with a 0-600 psi gauge for charge pressure. That would work for measuring it on your propel system as well. You can have a test hose made up at a local NAPA or you can even just buy one online at Discount Hydraulics. Don’t forget about the fitting that you will need to install into the pump. The size of the port was on the diagram on my previous post.

You also mentioned that there was water in the system. Another action I would take is disconnect the case drain hoses from all your pumps and motors. This way you can get that contaminated oil out of those components. I would also do the same on the system hoses.

After you do that, make sure you follow a good startup procedure. Here is one you can follow to ensure you have success.

Startup Procedure

I know it is a pain to do all that work, however it is worth getting that bad oil out and good oil in. Otherwise it can lead to continued issues in the hydraulic system.

 

[r8f1k]

Ok, I'm usually pretty good at tracking down odd parts, I can't find this seal kit anywhere. I have most of the measurements available through AVSPARE.com, I have crossed a lot of the parts, but for things I can't find, am I able to measure them and look up by size on HW Part Store.

 

[laurencen]

R18 in all my cases I simply give them the machine info as you do with dealers they look up the part number in there system, usually I buy the seal kits not individual seals

 

[r8f1k]

A little bit of progress today, pulled the hydraulic tank off, gave it a good cleaning, some debris, not too bad. That gave me access to the pump, pulled the two 1/2 bolts out that hold it against the drive plate and I wiggled it back to see if there was any issue with the splines. Splines look GOOD! Pushed it back in and pulled a couple lines off, drained more pink fluid and I noticed an inline check valve on the intake side. It seems to me something is wrong with the placement. It also seems very tight. I can see the same check valve in the diagrams from Case, but wouldn't it restrict the all of the fluid from going into the pump? The fluid would have to be fed by gravity and I don't know how it would overcome the check valve. The other side of the check valve is a 'T' and that comes from the oil cooling system. What am I missing?

 

[oldnslo]

Which port is that check calve connected to? The case drain or charge pump inlet?

Looking at diagram I suspect case drain but not certain that is correct.

 

[r8f1k]

Pretty sure it is the pump inlet

 

[Doaaj50]

Would you mind double checking based on this diagram?

If it is on the charge pump inlet, I can’t think of any reason why it would be there. It would only lead to more pressure drop that makes it more difficult to get oil into the inlet of the charge pump.

The only place that a check valve would make sense is on the case drain. If it is on the case drain port then it wouldn't let oil flow from the tank to the pump case. I have seen that if there are case pressure spikes from another component and they are trying to isolate the pump case from those events.

If it is on the charge pump inlet line, I would remove it. If it is on the case drain line, I would make sure it is working properly and the oil can flow from the pump to the tank. It should not take much force to open it. If it does, I would be concerned about it causing high case pressure in the pump.

 

[r8f1k]

Here is where it is