40 c hydraulic valve
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- MC crawler
- Posts: 2
- Joined: Sat Sep 15, 2018 12:39 pm
40 c hydraulic valve
My 40 wont raise the blade it has been getting slow now wont raise at all.It will lift the front of the machine off the ground but won't lift.I took the valve apart but didn't find anything.
Re: 40 c hydraulic valve
It sounds like the packing cup for the lift side has failed in the cylinder. The old JD cylinders used a separate cup for each side of the piston so they can work one way and not the other if one cup fails. Do you know what number your blade arrangement is? 61 was common on the 40c I believe. If you don't know about John Deere's free on line access to the parts catalogs go to either JDParts Homepage or JD Parts Advisor (links below). You enter your model number in the parts catalog search and it brings up models that have 40 in the title scroll down and you will find the tractor (PC 862). All the 40 series tractor models are in the same catalog. You can do the same for the blade, enter 61 as the model and see if it looks like yours. Get in touch with Lavoy, this is his site and I am sure he can help you out with identification and parts for the repair. He specializes in these old crawlers and sells parts for them, even some that are no longer available through JD. If he doesn't reply to this post you can send him an email at postmaster@jdcrawlers.com . Good luck.
JD Parts Advisor https://partsadvisor.deere.com/
JDParts: Homepage https://jdparts.deere.com/servlet/com
JD Parts Advisor https://partsadvisor.deere.com/
JDParts: Homepage https://jdparts.deere.com/servlet/com
-
- MC crawler
- Posts: 2
- Joined: Sat Sep 15, 2018 12:39 pm
Re: 40 c hydraulic valve
The cylinders are aftermarket tie rod cylinders I will check them. I think I'm going to up grade to a dual spool valve because I made the blade to swivel and will ad a cylinder to that function
Re: 40 c hydraulic valve
VERY IMPORTANT! if you change the valve you have to set the factory relief pressure to around 950 psi. Most new valves have a minimum relief pressure of 1500. And if you set it at that pressure you will destroy the pump. Most likely you will have to buy a lower pressure relief valve and plumb it in before your new dual spool valve.
1956 JD420, gearmatic 8a winch, custom 6 way blade and FOPS.
Re: 40 c hydraulic valve
Notmeu brings up a very good point, you need to be careful not to over pressurize a cam driven pump. Does your 40C still have the cam driven hydraulic pump, located at the right front of the engine, or do you have a different arrangement for a hydraulic pump?
My response the other day was based on thinking you had a 61 blade arrangement with the John Deere cylinder. Your aftermarket tie rod cylinders may have a similar packing arrangement on the pistons. Do you know the brand of cylinder to get a parts breakdown? You may have to open them up and take the parts to a hydraulic shop to be matched up. Just for the record is the valve the original JD valve or aftermarket? Is the blade set up an identifiable JD one you are modifying or something else? This type info is needed to get the best answers to your questions.
My response the other day was based on thinking you had a 61 blade arrangement with the John Deere cylinder. Your aftermarket tie rod cylinders may have a similar packing arrangement on the pistons. Do you know the brand of cylinder to get a parts breakdown? You may have to open them up and take the parts to a hydraulic shop to be matched up. Just for the record is the valve the original JD valve or aftermarket? Is the blade set up an identifiable JD one you are modifying or something else? This type info is needed to get the best answers to your questions.
Re: 40 c hydraulic valve
The problem is in the cylinder or cyllinders, not the valve. There is nothing to fail in the valve, only possibility is if the valve has been set for one way operation, but doubt that is the case here.
Lavoy
Lavoy
Parts and restoration for antique and late model John Deere crawlers.
Owner and moderator www.jdcrawlers.com
Owner and moderator www.jdcrawlers.com
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