John Deere 755 Episode VIII Part Three
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- Опубліковано 15 жов 2024
- Enough guesswork, it's time to clear the air (gap) between exhaust valves and pistons. Check out the end for information regarding assembly and future plans. Thanks everyone for taking time to watch and comment. Cheers!
Link to custom head gasket-maker www.cometic.com/
I just bought an old 755 setting for years in a field cause they couldn't get it to run. Looking around youtube No one has video about pulling and checking the injection pump so a good detailed episode on fuel system and bleeding would be very beneficial to many of us trying to figure these things out with out having to take to the dealer$$$. Thanks from Texas, for your videos and the time you have put into details.
You're welcome. Sounds like you found one like the one in the series! Preparations are underway to resume the project and an "expose'" on fuel system could be done for sure. In advance of that, experience has shown that often the simplest solution (Occam's razor), is the correct one. What I've found is that the common problems begin with the fuel pickup tube falls off in early models (tank in front of radiator), the three glow plugs fail to light (755 is indirect injection [IDI] and are required to start a cold engine, the lift pump fails to pressurize fuel to the injection pump (easy to check by opening the bleed screw), there's low compression in at least one cylinder, and bad fuel. I should have a 755 in the shop within a week or so (mid-February 2023) with hard starting, and will run through the exercise for the channel.
For your project, my suggestion is to eliminate the above list of possibilities before pulling the pump. If you hit a snag, consider bringing it up to my shop in KS and we can dig into it. Welcome aboard!
Awesome video, I especially appreciated the quick tutorial on how to set the valve lash. Its on my list of things to do on my 955 in the spring.
Thanks for the complement. Checking valve lash is just good business (and easy to perform). Another thing that I think is overlooked is frequent oil changes especially if tractor sits a while or doesn't get completely warmed up/dried out. These Yanmars, and other similar engines I suppose, have small ring grooves/rings and it doesn't take much to make them stick. Once that happens the loss of compression and uneven cylinder balance (loping) will soon develop and is unlikely to get better. As you know, 955s are rare and benefit from fiddling and a watchful eye. If you haven't watched Episode V Part II it begins with a good look at what poor fuel and a once-in-a-lifetime oil changes can do to rings and pistons. ua-cam.com/video/qa5o04zpE20/v-deo.html
Merry Christmas! Great to see the methodical progress on the rebuild.
Thank you for the unexpected gift of a Christmas greeting. In return, let me wish a very Merry Christmas to you and to those you may share it with. I realize it takes effort and time to post comments, but they remind us that we're not alone and that there are people who appreciate the work we do. Thanks again for posting the greeting that took me completely by surprise and brought a smile to my face. md
Crackin' work, really enjoying your videos. Many thanks. The clearances measuring out at within 1 thou of each other is a solid result, (24,23,24). The pipeline of projects sounds great, particularly the 855 with the con-rod making a bid for freedom. If there was a vote, id vote for that next! Have a merry, and recovery filled, Christmas, from Scotland.
Your vote has been recorded (and I'm inclined to agree with you). I am told, the 855 had an overhaul, a freshening up of the chassis (no paint), ran a bit, and "just stopped". We Industrial Archaeologists can't just look at something without asking the "W" questions and the 855 warrants an inspection worthy of a Tower House! In Episode VIII Part One, the 220 manual insists that connecting rod bolts must be replaced with new. From what I can tell so far, the "overhaul" was done in-frame so were the original fasteners reused? Ah, only as layers are excavated will we find evidence of the past! Thanks for the wishes and may I return same, less recovery (I hope), to you. From Michigan's UP Eh.
Excellent videos very entertaining
Thank you for commenting. By sharing the comment with a reply means we both matter, doesn't it? I think so. md
Happy Christmas from the UK. I really appreciate the detail you're going into in this series. Enjoy the holiday and I hope your convalescence goes well.
Thanks Mike. Consider your comments a "gift" and in return please accept my hope for good Christmas and New Year wishes for you and family. Had someone told me the 755 project could take a year I wouldn't have believed them, but others have said the same thing about knee replacements. "You'll feel better in a year" they say. Looking ahead that's a long time but both are "projects" that once started give a guy a purpose. Thanks again for the comments.
Well, I've watch all of your videos (thank you). Like you I'm reviving a dead John Deere 755. The good news is I have my crank, new bearings and pistons (.010" over) installed. Most other parts and tools are on hand to complete the project. I picked up my block and cylinder head in a hurry so was not able to talk to the machinist very long about how much was shaved off the surfaces. The bad news: Right now I'm measuring .035" piston protrusion and an old head gasket with a thickness around .055. I think you had .032" and .051 but somehow ended up with .023-.024" clearance not .019" How do you explain the discrepancy and how do you suggest I move forward. I plan to call my engine guy and see what he says. My valve recession is also out of spec. Everything is around .014-.018" Will valve recede into the head over time? Thanks again
The best explanation for variance is that my first measurements were done separately (P/H, gasket thickness, valve recession) and then combined to give me an idea of what was going on. Smashing and micing the solder "wire" gave me the actual clearance I had. I liked the idea that using an internal gauge (.061" solder) also accounted for any valve overlap that could interfere with the piston, thankfully not.
Ok, my suggestion is to replicate the procedure in Part Three - reassemble and take actual rather than "theoretical" measurements. This will show you what you have. Remember that a sheet of normal typing paper is 3-4 thousandths so that's not much. Yanmar is pretty consistent so my first thought is that the machinist took a bit more off the block than my guy and I could have been off a thou or two, but we're both pretty consistent in measurements. I pretty sure the valve recession will stay put as the seats won't move and any "hammering" of the valve would destroy the sealing surfaces and cause other problems...no, they should stay the same.
I'd like to see you assemble with the old gasket and use more wires around pistons. Its additional work but a bonus is that it will give you a rehearsal of putting it together for real, before adding silicone. You'll have gained confidence knowing clearances and what to expect with timing and the gearcase locators. BTW, for sealing the gearcase and other parts, I suggest buying it in the 10 oz. tube. I don't remember the exact part number but will look for the permatex black we use and let you know. Its easier to control continuous flow and doesn't cost much more than the 3 oz. tubes. Let me know if you have any more questions and just remember to have fun with it.
I use Permatex Ultra Black Gasket Maker #24105 in a 10 oz tube for gear case and oil pan sealing. Holding the tube in a caulking gun really helps apply a uniform and continuous bead. Assembly takes more material than one thinks so best to have a second tube ready. Let me know how it goes. md
@@markdice2500 I finally checked my piston to head clearance with some .060" soft wire. I used three pieces of wire and my result came out to .027" Measuring the piston to head clearance separately I came up with about .020". I am pretty happy I don't have to pull things apart and shave the pistons. Thanks for your encouragement and advice.
@@selfsufficientlifestyle8686 Glad I could help. Please remember to replace the con rod cap bolts. I haven't gotten into the 855 with rod through the block yet but believe the cap let go either from improper tightening, or, a bolt let go. Watch for the archaeology on that project coming up soon. md
Dang. Didn’t know about the knees (Still new to your channel) that had to be a tough ordeal. BTW, I had family that lived in the U.P. (K.I. Sawyer)at one time. Heard it was beautiful up there. Best wishes on the knees👍
It is nice up here but don't have a place to work on the tractors.. Started a fire last night (6/26)! md