'73 MF135 Perkins diesel AD3.152 help

[namyessam]

If you end up drilling it out, use a high quality high speed steel drill. You could start with a smaller drill maybe a 3/16 or so to make drilling with the large one easier. I believe the bolt is a 7/16 diameter so use at least that size or 1/64 to 1/32 larger. Most Allen head bolts are grade 8 and are tough drilling. Spin your drill slowly, 250 rpm or so and light pressure to start with until you get past the hex and into the base of the bolt. When an Allen head bolt socket has been stripped out it seams to work harden them and make it even tougher. You should only have to go a short distance and the head will pop off and probably get stuck on the drill and you should be able to pull it out of the hole. I would think you should be able to lift the valve off the bolt shank. Remember to clean the chips off good to keep them out of the hydraulic ports when the valve is lifted off. I thought you said you felt the thread were loose and that is the norm for Allen head bolts, Its been my experience that the head sticks to the bolted item and the threads are loose and as soon as you drill the head off the rest of the bolt unscrews with your fingers. Good Luck.

Just to let you know, I am a journeyman toolmaker with 30+ years experience. I use Allen head bolts on a daily basis. Allen head bolts are the primary fastener used in tools for industry. They are normally in a counterbore so they are below flush with the surface. I had to drill one out last week and used the same process I described above because "Jack Armstrong" overtightened the bolt. Use your best judgement. I was reluctant to post this informatin due to the conflict earlier in this thread but reconsidered because this in my line of work. Its what I do for a living. Good Luck again.

I should correct myself and call the bolts by the proper generic name of socket head cap screws. A left hand drill is an old trick that it bites hard enough it may back the bolt out with out completely drilling it out. What ever method you use, don't break a drill or an easyout or you'll really have problems. I know this is a wild idea but can the whole valve be turned with the stuck bolt intact?? My tractor is 50 miles away and I can't look at it to see if there is suciffient clearence to do so. If that is possible it may solve your problem. This would destroy your o-ring which should be replaced any way. I don't see anything in the parts breakdown that sticks down from the valve or sticks up from the top cover. Maybe someone like MasseyWV can confirm this.

[The kid]

I guess I need to re-read my posts, but no the bolt is not sheared at all. The inside hex that the allen wrench is supposed to grab has stripped. It was full of water/mud/rust, I cleaned it the best I could before I started trying to get it to loosen. Funny thing is the rear bolt was easy to get loose. Oh well, I'll get it eventually....

Even using an "easy out" may be a challenge, but it's about your only solution to grip the stripped bolt to twist it out. Especially a bolt below the surface. You may also have to use some heat to loosen the rust with a fine tipped head to shoot a narrow flame into the hole. A regular propane torch should do the trick. Get your hole drilled using three sized carbon bits to get the hole about 3/4 size of the bolt. The drilling might loosen the bolt, but if not. Then your going to have to apply some heat on the bolt to soften the rust. Sad part about all this it could have been prevented if a waterproof plug was inserted after that valve was put on. Simple as using caulk would have worked. A small squirt of silicone sealant in the hole. Whatever you do, buy a high quality set of extractors and drill bits. I usually take a good set of adjustable wrench to twist the extractor out.

You mentioned using a left handed drill bit. Your still going to have to drill it out to a point. The extractor is designed to remove a stuck bolt/ screw. A left handed drill will do the same thing a right handed on does. Drill a hole. Extractor kits are not that pricey but priceless when you need them. Just make sure you drill deep enough for the extractor to grip and do it's thing. -kid

[lugnut1009]

namyessam, I didn't think about that but I agree, most of the cap head allen screw type bolts I've dealt with were grade 8 now that I think of it...

I didn't want to use an extractor because they seem to spread out whatever you insert them into, whether it be pipe or a drilled out bolt/screw. And it did have the little plastic caps in the holes, but after 30-40 years they were kind of deteriorated. I haven't had a chance to look at it again since the other day. I'm hoping the Kroil oil has penetrated and loosened the rust so I can get it out easily.

We shall see!! Hopefully this weekend, I will also have to come up with new bolts too. Parts fische on AGCOpartsbooks.com says they are/were 7/16" x 1 3/8" hex head cap screws, just so happens that's about the strangest bolt to find about anywhere, ha!

[lugnut1009]

... I know this is a wild idea but can the whole valve be turned with the stuck bolt intact?? My tractor is 50 miles away and I can't look at it to see if there is suciffient clearence to do so. If that is possible it may solve your problem....

I tried this, it hits the hydraulic top cover in the back of the valve...

You can see it better in this picture I took several weeks ago when I first joined.

[namyessam]

I figured you probably tried it but I thought I might ask anyway. Sometime the most obvious solutions are right in front of us and we miss it. Then we say DUH why didn't I think of that. Kroil is good, I use it, but need to find where to get more. Hopefully you will not need to drill and risk all the chips in the hydraulic ports. That would be bad for the whole system. A supplier called McMaster Carr based out of Chicago could supply you with all the odd bolts you need. They have a catalog that about 3 inches thick and are online also and have about every oddball item you would ever want.

[The kid]

namyessam, I didn't think about that but I agree, most of the cap head allen screw type bolts I've dealt with were grade 8 now that I think of it...

I didn't want to use an extractor because they seem to spread out whatever you insert them into, whether it be pipe or a drilled out bolt/screw. And it did have the little plastic caps in the holes, but after 30-40 years they were kind of deteriorated. I haven't had a chance to look at it again since the other day. I'm hoping the Kroil oil has penetrated and loosened the rust so I can get it out easily.

We shall see!! Hopefully this weekend, I will also have to come up with new bolts too. Parts fische on AGCOpartsbooks.com says they are/were 7/16" x 1 3/8" hex head cap screws, just so happens that's about the strangest bolt to find about anywhere, ha!

Do you have a TSC in your area? They have a pretty good selection of allen type bolts.

[namyessam]

Kid, I was thinking the same as you that he needed allen bolts when I mentioned McMaster Carr. Lugnut said he needed standard hex head bolts to install the new cover instead of the aux. valve. I missed that description. Hex heads should be a little easier to find than allen head even 7/16 coarse thread.

Lugnut, I looked at tractor supply online and found you have one in Vicksburg. They should have bolts available either in their regular bolt section or their special section.

Murphy good call, I never thought of them, They have one in Vicksburg, and they'll have whatever he needs. I wouldn't even bother with tractor supply

namyessam

[murphy1244]

Try Fastenall if you have them, They got everything.

[The kid]

Kid, I was thinking the same as you that he needed allen bolts when I mentioned McMaster Carr. Lugnut said he needed standard hex head bolts to install the new cover instead of the aux. valve. I missed that description. Hex heads should be a little easier to find than allen head even 7/16 coarse thread.

Lugnut, I looked at tractor supply online and found you have one in Vicksburg. They should have bolts available either in their regular bolt section or their special section.

Murphy good call, I never thought of them, They have one in Vicksburg, and they'll have whatever he needs. I wouldn't even bother with tractor supply

namyessam

Hex head is referring to the hex design of the Allen fitting. You got to remember they didn't call them Allen in the parts book. A button head or something like that. What he needs is Allen screws of same size and length. Allen's have round heads and that"s what's down in the hole. I researched a few remedy s and they mention taking the next size up Allen and tapping it into the existing one.. Or using the easy out method. That hex head is probably hardened carbon steel. That has to be dealt with slowly and using oil while cutting. Once drilled below the hardened area the " extractor" can be used to gently twist it out. If croil doesn't penetrate then some heat has to be put down the hole to soften the rust and the "easy out" will do it"s magic. The extractor doesn't expand the drilled area. The drilled area is giving the extractor something to bite to since it is reversed screw in design. I bought a sears set years ago and have used every size in the box at one time or another. Just be careful with the heat since your dealing with a hydraulic fixture. Try to only heat the offending bolt. Possibly putting damp rags around the bolt hole to keep the temp down on the surrounding area.Note: use a small bit to start when drilling using light pressure and make darn sure you are straight down the bolt. Drilling at an angle is bad Ju Ju. Try to stay centered. Once the small drill is deep enough, move up the the next size, till you get at a diameter for a easy bit to go in.

[The kid]

Kid, I was thinking the same as you that he needed allen bolts when I mentioned McMaster Carr. Lugnut said he needed standard hex head bolts to install the new cover instead of the aux. valve. I missed that description. Hex heads should be a little easier to find than allen head even 7/16 coarse thread.

Lugnut, I looked at tractor supply online and found you have one in Vicksburg. They should have bolts available either in their regular bolt section or their special section.

Murphy good call, I never thought of them, They have one in Vicksburg, and they'll have whatever he needs. I wouldn't even bother with tractor supply

namyessam

Now securing the cap Murph is right a standard hex head bolt will do. To replace the bolts for a later install he will need Allen type.