normde2001
Elite Member
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- Mar 10, 2002
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See post #4.
Just won't go
- Thread starter heloman88
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Missed the second half of your original reply somehow. I will look into that. No way to test the pto under load yet as have no attachments other than a scrapper.
normde2001
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Can't tell you exactly where it is located, but every Yanmar powershift has it. Usually a plug with large screwdriver slot holding it in. You may need a parts manual unless someone has more info.
rScotty
Super Member
- Joined
- Apr 21, 2001
- Messages
- 9,676
- Location
- Rural mountains - Colorado
- Tractor
- Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
First of all, welcome to the forum. The YM187D is an excellent example of a vintage Yanmar.
I'll post some literature for you at the end of this message. Good on you for ordering the manuals. Yanmar printed several versions of workshop manuals. There is a bound version that is sort of a synopsis, and then the large OEM shop manual that is the heavy red plastic ring binder type. I see there is one of those on ebay right now for the YM336D. That's the one to get. Yes, they are expensive....but are argueably the best shop manuals ever printed. Very high quality paper and pictures. Lots of multicolored artist's exploded diagrams and technical discussion of how things work. Very impressive manuals. I used to collect shop manuals and those OEM Yanmars are among the best - right along with the JD technical manuals. Big heavy clunky manuals, but nice.
Regarding the brakes, they were deliberately made to be sealed against water. Yanmar advertised that this was because the tractors were developed in Japan for use half-submerged in rice paddys. Frankly I doubt that because if true the sealing would have been better. Anyway, for the USA use, those sealed brakes were horrid on every model. They always rusted. You will be better off to fix the brakes and then modify the brake covers so that they have lots of ventilation and drainage in the brake covers. Drill half a dozen quarter inch holes for drainage in the bottom of the cover and fabricate a rain shield, Thenput some air intakes in the top of the cover. For air intakes I use soft copper tubing. That way I can tap the cover neatly and then orient the air intake down so it does'nt collect rain water. To repair: Turn out the brake drums on a lathe - there's plenty of meat there which is good because of the way those drums rust pit. Next badly pitted ones that I do I'm going to look into industrial hard plating for the drums. Then have the shoes re-coated with friction material to match the new drum radius. Just about any set of soft brake springs will work if the pivot and pivot bushings aren't worn.
Put JD 303 trans-hydraulic fluid or equivalent in the tranny. Get ALL the heavy gear oil out. System will not work with that oil. This may require several flushings. Flush with your favorite oil/diesel mix or cheap trans-hydraulic fluid from some wholesale tractor shop. That will work fine.
The power shift has it's own internal hydraulic pump for both clutch pack pressure and forced lube pressure. They are 2 different internal circuits. The whole tranny is very, very clever. No, I've never had one apart...wish I had, though. They are nifty and I'd like to see one up close. Problem is that they are nearly bulletproof. You rarely ever hear of a power shift having a problem other than dirty filters. Although yours may require a disassembly and internal cleaning. But check the pressures first. The shop manual will give you complete instructions for testing the pressures of each circuit. In the manual, transmission mechanicals are in section 50, testing procedures in section 250.
Test the power shift pump pressure (1/8" NPT in top or side of regulator case, front plug is control pressure 200 psi, rear is lube oil pressure 6 psi).
From what I've heard over the years, if pressure is low or takes more than a half a second to build then it's either worn pump, restriction in the galley, clogged filter, or stuck relief valves.
Good luck....get all the manuals you can. That's a machine worth the hassle. BTW, there was an optional power steering cylinder available at one time.
rScotty
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normde2001
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Aaron posted a pic in the Hoye forum on 7/10 from the service manual. Apparemtly totally different.
Thank's for the very thorough and thoughtful reply. I appreciate the time you took to help me figure this out. As it is right now, the machine is working, just not correctly. Unfortunately I am in the middle of a project with it and have decided to continue using it as is, since I really don't know what all I am going to find once I start crawling thru the thing. I'm afraid if I open it up, that will be it for a while and I still need it, even if its just for 15 minutes a day.
It really is sort of weird, one day it almost seemed normal after I had used it for about an hour, then yesterday right back to looong hesitation before it finally starts to go. It definitely is some sort of build up of fluid pressure not happening, or being by-passed thru a valve. I probably will at least open the cover tho the relief valve and see if there is anything obvious.
I'll report back what I find but it may be a while before I really look into it. Again, thanx to everyone for pointing me in the right direction.
Forgot to mention rScotty...thank's for the very cool original brochure pictures. Sure wish mine still looked like that!
clemsonfor
Super Member
aren't there springs or something in these valves that can cause issues. I was thinking we saw one here a few years back that needed a spring or a check valve replaced. I don't remember the issues it had but I do not think they matched this tractor, but If I recall there were several of those "valves or springs" in the tractor that could cause issues with the PS
Yeah, the springs and/or the relief valves have been suggested before (post 4), I just have been hesitant to open anything up to start snooping around as I am using the machine in a project right now and hate to ground it if I run into trouble or parts I can't find. It does work, even as is, just at about 20% of what it should be doing. Don't think it is doing any more damage running it easy as apparently the previous owner used it this way for several years. Not sure exactly what I will be looking for when I open the relief valves, but hoping it is something obvious, like broken springs or full of crud. The 187D seems a bit more than just unscrewing an inspection plug to access, and it shows a number of o-rings and such I'm sure I'll have to replace even if all I do is inspect. I also think I'll do another flush of the entire tranny in case some gear oil remains in some of the nooks and crannys. Done it twice already and gets a bit spendy, but it definitely seems better than the first day I ran it.
I'll post an update if I get too impatient and start taking things apart.
clemsonfor
Super Member
im thinking its maybe like ball bearings and springs....I probably am making that up though! ha! I think previously there were springs that were broken and maybe hard to locate? Just a note I learned from Aaron at Hoye. Yanmar uses Japanese spec orings for many things, your metric or SAE wont qite be the right size. They may but also maybe not seal right. I suggest looking at the orings you need for the job and or calling Aaron or emailing him a question and asking what orings you would need for the job your doing and then buying 2 of each of them to have on hand before you start.