T5B backhoe control valve rebuild

[grizzy67]

I share a T5B with my neighbor. I do all the maintenance on the tractor I'm planning on rebuilding the backhoe valve assemble, It's a greason (spelling) valve assembly. I'm new to something like this. I'm not sure which set of O rings it will need for the rebuild. I'm not sure what I will find when I open everything up. We do have the parts book and it says old style seals and new style seals. 'When I take this apart what will I expect to find. Do you think it will need any other parts during the rebuild? Everything works at this time but some of the valves leak back like the outriggers and the main boom etc. When I got into the picture they had been filling the hydraulic reservoir with regular hydraulic fluid instead of a approved oil so I figure it has caused degrading of the seals On the otherhand I would like to change the valve around in the lineup the same as the T6C and fabricate the swivel block to use joy sticks to control two valves at the same time to make it easier to operate. The two outrigger valves are on the outside and they would move to the center to allow space between the two joysticks. will it will come apart without breaking a bolt or two. All info is appreciated, I've looked for a replacement unit but haven't found what would work yet.
I'm not sure about the difference between open or closed valves, whether I can move the outrigger valves to the middle without causing any problems.
Please educate me on what I'd like to get into here. What other parts will it require, where would you buy the seals? Do they come as a kit or individual set per valve? Will I need any special tools? All help appreciated
Thanks for your help,
Mark

 

[Dart1917]

I did mine on my T6 last year. I took them all apart and measured up the orings and ordered them from McMaster Carr. I got bags of 100 but I think it was still a lot cheaper than kits. The only special tools you should need are a set of picks to get the orings out of the inside grooves. I think you should be able to change the order but keep all the parts with the valve they came from and pay attention to where the relief valves go, they are not all the same.

 

[grizzy67]

I did mine on my T6 last year. I took them all apart and measured up the orings and ordered them from McMaster Carr. I got bags of 100 but I think it was still a lot cheaper than kits. The only special tools you should need are a set of picks to get the orings out of the inside grooves. I think you should be able to change the order but keep all the parts with the valve they came from and pay attention to where the relief valves go, they are not all the same.
View attachment 641397

Thanks Dart, The photo tells a lot, I'll check out the manual I think they give sizes for the O-rings.
Well the O-ring description I have is from the T5C parts manual I also have. I would assume where they description of the old style O-ring, this should be the ones to get. I'd prefer to have all the O-rings ready to go so not to keep the tractor out of service very long. I'll be out today moving snow.
How do you tell which valves are open or closed center?

 

[Dart1917]

Here's a link to the Gresen service manual. I think they are all open center so it shouldn't be a problem changing the order. But I'm not an expert on hydraulics so I could be wrong. Read the manual, page 3 has info on identifying the sections. I think I have a list of what orings I bought but I'll have to dig to see if I can find it.

Edit: I looked and I don't have a list of which orings go to that valve. I can look back at my McMaster order history but I also did the loader valve and all the cylinders so I don't know which rings went in the backhoe valve. Mcmaster is quick to ship, if you order online you should have them in a few days.

http://www.phtruck.com/download/hvd/HVD-Service-Literature/Gresen-Spare-Parts/V20SpareParts.pdf

 

[jheissjr]

You mention the main problem is some of the cylinders are leaking back like the outriggers main boom. Another cause of leak back are worn seals in the cylinders. When leak back occurs, the two possible causes are leaking seals in the control valve or leaking seals in the cylinder.

 

[grizzy67]

Thanks guys for the responses, I’ve got the T5C manual with me so I値l check the sizes of the. Old style O-rings. My guess is that is same value and seals as the B. I値l also check on eBay I致e seen gresen V20 seal kits in the past.