touch control rebuild help

[tomstractor]

I need to rebuild my TC on my LO Boy. I have searched for a step by step help and only find 1 for the old style, There is 1 for the newer style
but all the pictures are deleted. Does anybody know where to find some help?

[Don McCombs]

Dale Finch.

[Dale Finch]

This is the HOW TO for the newer block:
http://farmallcub.com/phpBB2/viewtopic.php?f=141&t=42857
Be extremely methodical, keep things clean, and take pictures of things as you go...you cannot take too many photos!!

Lay everything out in the order removed... I used a large silverware tray from Walmart. During reassembly, use plenty of HyTran... I poor it into every nook & cranny of the block, then dip each piece in it before assembly.

Try to do it all in one day... you'd be surprised how quickly things that look clear & obvious, will be forgotten the next day!!

Another thing, before the final cleaning, run your fingers in all the holes feeling for any burrs. If you find any, use some fine emery paper to remove them.

I forgot, also, in addition to thoroughly cleaning the exterior before disassembly, when it's apart, I spray carb cleaner in all those nooks & crannies, then blow it out from every hole (be careful...suggest goggles!).

[Glen]

Hi,
When you are done with the rebuild, below is a post I made about checking and changing the Touch Control fluid, and removing the air from the system, if you need it.

viewtopic.php?f=1&t=106664

Be sure to check the Cub Touch Control fluid level with the arms in the rear or down position.

[lyle11]

I did this last fall but haven’t tested it yet due to cold weather and no heated place to work on it. So, I’m no expert but here are a couple of things.

Be very careful removing the big strainer. I couldn’t get mine out without damaging it and needing to buy a new one. Mine was too long and was crinkled slightly at the end once installed. Impossible to remove without causing damage. Common problem. Steiner strainer is foreign made but quite a bit cheaper than TM Case part and fits good. Maybe your existing strainer will be the right length.

I rebuilt one but bought an extra unit cheap due to roughness in the piston cylinder. In my original block, the values were very hard to remove. In the block I bought, most of the valves came out as a unit and it was easy.

The IH manual covering this procedure says to remove them with a Lock Ring Plier (External). If they don’t come out or parts of the valve remain in the block, I’d resist digging with a screwdriver and scratching them and get this tool.

Instructions say something like “check for wear and replace worn components”. I didn’t know how to assess wear but did see obvious scratches and wear on one valve, I’m sure caused by someone working on it getting impatient and digging with a screwdriver scratching the walls inside the valve body resulting in scoring of the piston. I got one on the Vine from a forum member.

I put a little tip in a thread about using a shaved toothbrush handle if you end up with the inner part of the valve with a small 1/4” or so orifice stuck in the block. This happened to me 3 times and worked well for the cost of a toothbrush.

Two of the valves have a little wavy disk shaped spring that sits in the very bottom of the hole in the block. I did not replace them. Steiner carries them if you want to replace them. In my spare block one was broken.

TM kit has all the o-rings but they aren’t individually packaged with a part number. For some, like the real big ones, it’s obvious where they go. Just to be sure, when I removed the smaller old O-rings I measured them and measured the new one OD and ID and thickness just to be sure I have the exact one I need. The real thick small one goes on the Control valve.

I used 2 cans of acetone based carburetor spray to clean the parts and block followed by compressed air.

The instructions make a big thing about rotating the valves with the new o-rings as you insert them. These valves consist of multiple small parts including tiny coil springs that have to go in in a specific order. I don’t see how you would be able to rotate the valve while inserting. It seems silly to me that inserting a valve with a new well lubed o-ring is gonna fail quicker than if it’s inserted with a twist. It’s hard enough just to get it all in because the internal parts will fall into the hole. Just lube it real good with Hytran. I set the block with the head side tilted slightly downward so I could insert the valve components as a unit facing slightly upward to preventing the components from separating.

I don’t recall the torque specs for the bottom plate but they are 5/16” bolts and I didn’t go as far as the spec called for. Maybe my torque wrench is off but I was nervous about snapping them off. Or, it could just be my Herculean strength. I think it says 35 foot-lbs and that seems like a lot for a 5/16” bolt.

I did use Indianhead gasket shellac on the bottom plate gasket only.

Make sure the connecting rod that goes inside the big piston pivots. The one from my original block was stuck in one position. I’m pretty sure that’s why my piston leaked. I couldn’t get it apart but the one from my spare block pivoted and came out fairly easily so I could replace the o-rings.

I’d probably take it apart before I order a rebuild kit in case you need the strainer or you want to replace the 2 little disk shaped springs that aren’t in the TM kit. Also, you may need to order the Connecting Rod bushing or need new boots.

If you are in a hurry, my last 3 day shipping order from TM was shipped on 1-12 and arrived on 1-21 using USPS. Pay extra for UPS if you need it fast.

2AE58977-060C-462D-AE97-4DACB60B7762.jpeg (28.46 KiB) Viewed 405 times

[Glen]

Hi,
The strainer slides out the head end of the Touch Control block, after removing the Touch Control head.
The strainers slid out easily without any damage on the ones I have worked on.

Some of the strainer screens get old and break, the screen is already broken before you try to remove it, that might be what you had lyle11.

I think the strainers are slightly longer than the space so they will seal at the ends when you put the head on, it makes them squish slightly.

Below is the Cub and LoBoy service manual, it has lots of info. The Touch Control is in section 8, I would read it before repairing the Touch Control. It has info for older Touch Controls too, disregard the info for part numbers of blocks that are not what you have.

http://farmallcub.com/rudi_cub/www.clea ... index.html

[tomstractor]

I have it all apart and the screen seems to be a little long so it was a little crushed but came out and was not broken. Some of the valves were tight but with the tool Lyle described they came out. I did not find "dished shaped springs". I did find springs like wave washers at the bottom of 2 valves.
They say to take the main plunger out the front, I took it out the back with all the other valves with the con rod still attached. Will finish cleaning
and assemble in the morning. Thanks for the help.

[Dale Finch]

It's the control rod that goes out the front...all the rest go out the rear...head end (at least on the newer block style).

Be sure to check for any burrs, and smooth any out, before reassembling. Good luck getting that o-ring on the control rod...it brings out some colorful language!!

[lyle11]

It was the wavy washer springs you found that I was referring to. I was in a hurry and didn’t come up with an accurate description.

[lyle11]

When I removed the old o-rings, I used a safety pin and carefully pierced the o-ring without contacting metal so I could pull it up and cut it or pull it off. I didn’t want to pry and scratch the metal.

That’s another thing the instructions make a point about to “roll” the new o-rings on. Once you get it started it’s hard to say if it’s rolling or sliding. Most of the o-rings from TM have a little white dot on them which I think is so you can tell that it’s not twisted after it seats into its groove.

[Jim Becker]

Dots on o-rings indicate something about specifications (often material). There is no standard so by the time they get to us, it usually doesn't mean anything.

[lyle11]

Dots on o-rings indicate something about specifications (often material). There is no standard so by the time they get to us, it usually doesn't mean anything.

Now that I think about it, a couple of the o-rings had a pink dot so that makes sense. I read about how you need to make sure your o-ring doesn’t get installed with a twist in it. But, these small o-rings, if well lubricated, seem to easily pop back into their original shape once in the groove.

Some car oil filter canisters (Toyota) use a large diameter thin type of o-ring. I can see how it might end up twisted.

[tomstractor]

All the "orings" are installed and going back together. The book says to tighten the 5/6 bolts to 35lbs and the 3/8 bolts to 45lbs.
I can not believe that. I would normally torque 5/16 grade 5 to 18 or 20 and 3/8 to 25. I think this must be a mistake.
What do you think?

[Dale Finch]

I almost twisted off a bolt doing one...I really think it is too much, but I'm certainly no expert.

[tomstractor]

Do you use any sealer on the gaskets and sealer on the bolt threads?