Farmall 706 auxiliary valve leak solution possibilities

This message is a reply to an archived post by Weldon K on May 20, 2016 at 14:06:24.
The original subject was "Re: Farmall 706 auxiliary valve leak solution possibilities".

Hi Weldon:
Is there any chance you have a part number or dimensions on that tiny o-ring? The plunger in mine seems OK, so the ring would be a much cheaper avenue.
Thanks,
JimO

that little o ring is not serviced separately so you have to buy the plunger. Ive tried in past to put new o ring on it and it doesnt work believe me.

OK, thanks. The place I get stuff is going to have to order it from Oregon; I'm in Wyoming.
Working on these old tractor isn't for sissies.
JimO

Hi,
I'm sorry but you can still buy the o-ring(3.00).Also I have put them on many times. I will admit it is a little tricky,but it can be done.

marlin

HI,

Sorry,for got the part #377805r1 o-ring

Hi
Did you get that part number for CASEIH? It shows up as "gasket" on their website. Bates corp. website lists it as part of a $348 gasket set.

Thanks,
JimO

Hi,
Part #377805r1 is an o-ring and it is 3.00.I have just ordered them lately so I know it works. Like I said they are tricky to put on but,can be done.

Jim
I did some internet searching for IH part no.
377805R1 and found this site
http://www.machinerytrader.com/list/PartsSearch.aspx?partnum=377805R1&PST=Exact


Also found an old o-ring and unlatching piston so I made photos showing o-ring beside a measure. Marks on measure are 1/16th inch. Best I can measure , the o-ring is a standard size identified as a " 002 " according to specs from an o-ring site.
Photos included may help you.
As I stated in post from months ago , I got the small o-ring from a local hydraulics repair shop.

WOW! That's a great amount of information Weldon! It is greatly appreciated by me and probably a few others!
I had already ordered the regular part. It's not going to break the bank but it's not cheap either, and the shipping etc. will make it even worse. A $3 part is a great thing to know how to get.

And for everyone who has provided me with advice: thanks. A couple nights ago I woke up at about 2AM and was thinking about this valve stuff (yeah, I'm getting older...) and I suddenly realized how the darn thing works, mostly. So now I know how to put it together even though the person before me muddled it up pretty bad. With any luck at all, I'm going to be done with the maintenance before the snow arrives. Thanks again.
JimO

When IH came out with that valve, they did furnish that o ring no problem. I remember the parts man having trouble getting them on the display rack. I think he ended up using a small finishing nail because the hole was so small. Replaced a few but then they would not supply them any more, just the piston with o ring assembled.

Another thing, on finding that piston in the center of the valve. Two things can cause that but both normally require the o-ring to be worn and not have much tension in the bore of the actuator. When you drop a load real fast, you can get a negative pressure in the valve and "suck" the piston out. The other is when ever that detent kicks off it gives that piston a jolt and can kick it out. If I ever had a repeat performance of that piston ending up inside valve spool, I installed a rod in the spool. Big enough to keep piston out, but small enough to allow oil to still flow around it to unlatch the piston. Worked out . I have seen them where all of a sudden a stream of oil is shooting out that hole in valve (it blows the plug out) and then pulling lever again would shoot that piston back into place and not leak.