641 Hydraulic Parts

Hello all,

My neighbor is trying to get his 641 back in working order. The main problem he has now is the hiccuping of the hydraulic lift. I've been tasked with trying to find parts on line, as he doesn't own a computer. I've looked through several of the threads regarding the problem he's having and thank you guys for the years of knowledge deposited here.

The question I have is whether the parts he's asked for are even available anymore. I've tried matching the diagrams to the YT parts, but I'm not terribly smart on tractor parts.



What I get is that he wants the entire check valve assembly, the friction disc, which I did see in the 641 parts catalogue, and a spring of indeterminable size. I've seen one valve assembly, FDS3391, which I don't know if it replaces the circled collection of parts (13-22).



And on this he is looking for the unloading valve assembly, with the gasket, which I have no idea why it deserved an asterisk. I'm guessing he's wanting to replace the assembly without buying the whole cylinder with the valve assembly in it, which was about $600.

Overall, I guess the main question is whether these parts are available, if there's going to have to be some reverse engineer some solutions. Again, I apologize for my general ignorance, but I guess that's why they put me on computer duty. I appreciate any help you all can offer.

I believe most of those parts are no longer available new. Maybe some used. Here we leave facts & go into opinion. Looks like a shot-gun approach......I would not expect all those parts to be un-useable, so I would try to pare down my wish list to just those that absolutely can't be used or else try to find the whole assembly as a good used assy.

the unloading valve is sticking take it apart and clean it replace the o ring and leather wiper on the piston soak the leather in very hot water to get it to stretch over the piston then let it cool and dry before assembly check the cam pen its most likely worn you can reverse it or replace it that usually solves most problems.

(quoted from post at 11:32:03 05/25/17) Hello all,

My neighbor is trying to get his 641 back in working order. ...

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You'll have to forgive me as even though I'm using a Ford 851, I'm not a "Ford man". But in looking for parts, I have been around this type of tree before.

What you have there is an aftermarket service manual. What you are needing is a 641 parts manual. Reprints are readily available on the web. We have a local CNH dealer nearby (was Ford for decades) who will readily provide parts manual pages, by fax or in person, and has a parts woman who rarely needs to refer to a manual to pull the correct part off the shelf. You may be lucky and have a local parts person who has been there decades and knows Ford parts inside and out and is willing to help, or you may end up talking to a box of rocks. Anyway, the parts manual will give Ford part numbers which can then be ask for directly from your local CNH dealer, or accurately searched on the internet.

If indeed you are looking for obsolete parts, you can check depotparts (dot) com who buy old model NOS (new, old stock) parts so some dealer in Podunk isn't sitting on 2 check valve springs for a 1956 model they won't likely sell, and offer them globally. They don't sell direct, but your dealer can order from them.

Failing that, there is little that once made, can not be made again, perhaps even better. I've been blessed to have connections in tool and die shops where I can either use their machines to make my own replacements for obsolete parts, or hire them to do so, often at a fraction of what a "genuine replacement" (if available) would cost. If you or your buddy plan on doing more tractor repairs and don't know of anyone in a machine shop, I'd put getting to know one high on the "to do" list. Good ones will be glad to take on a "one off" project, especially if you aren't in a hurry - some enjoy having small projects to fill machine and operator time, but by all means, ASK BEFOREHAND what they think it would cost to make 'this part' for you. If you get a good deal, buy the shop a pizza, or donuts (or case of beverage of their choice) - they'll remember you and be more willing to help in the future.

hope that helps.

Wow, you are looking at lot of parts. Most of them are probably just fine. The check valves and back pressure valves rarely give any problems. I would leave them alone.

Hiccups are a sign of a small leak on the lift side of the system. It could be several things and can be hard to track down. One thing to try is put a weight on the three point, start the tractor, raise the weight and stop the tractor. Pull the round PTO cover and look inside with a small flash light and a mirror. With luck you might find what's leaking.

If I were pulling the cover, I would get a gasket/o-ring kit from YT. and piston o-ring, backup washer, and unloader valve from CNH (Messicks). Also get part 29 and 30 from YT. 29 almost always need to be replaced and you usually break 30 getting it off.

Post back if you need help, but definitely service the unloader valve and piston. Also, check the cam follower pin and adjust the linkage according to the I&T manual.