Back to my JD 350 loader.

Bobg3204

New User
Doing a service and all is going smooth as silk until I get to the hyd res filter. I've never replaced it because hydraulics work perfect and I check for water on a regular basis. I pulled the bolts and started to remove the top to R&R the filter. The lid will come up a 1/4 inch and stop - no side to side movement either. Just froze. I broke down and bought a service manual and as with all manuals it does not have a section on unusual circumstances. I also noticed a nail was inserted in the poppet which I had never noticed before. Another thing I discovered was the lid was sealed with permatex which is a big no-no in my book so I know something had gone bad in the past. I'm curious if this problem has been encountered before and any suggestions.
 
Yes, I've come across that problem many times when I was a Deere mechanic. The filter is either half-way off or it's blown apart and too fat to come up through the hole. Just force it off. There is nothing to stop the cover from coming straight up except the filter IF it's not in the right place or no longer the right size. I rarely find a 350 of that vintage with the filter in place. That's because they are difficult to install properly so many times - they are not. I described that problem already. The thing you are calling a poppet-valve is the return filter restriction indicator. When the oil is cold - even with a clean filter - it will bob up and down until the oil warms. If the filer is partially plugged - it will rise all the way up and stay there until the filter just blows apart or blows off. Deere had a lot of problems with that setup. One fix was a filter that allowed more oil to pass. Another was thinner oil. When you put a new return filter in - you cannot just install with the long bolt. You MUST have the long hollow metal bushing that goes inside the filter and allows the bolt to be tightened without crushing the filter. Most times - it's missing.
 
Yes - absolutely correct as always. Thank you. Got it out and the previous owner had used silicon on every part - even globs sticking to the filter. There was no steel sleeve on the bolt so I turned one on the lathe to get the proper crush to the filter (fortunately the length is listed in the manual I have). Also... I want to mention that I searched all your past posts and printed quite a few of them. In 2011 you posted a rely to a fellow who just purchased a machine and asked you about how to service it and what to use. I'll say your detailed reply as well as others are now inserted into my manual. I can't thank you enough for your help.
 
Yes - found it and it was mainly plugged with silicone with a smattering of debris of other types. I spent an hour cleaning the screen - gave up and bought a new one. I'm surprised the hydraulics worked as well as they did. The main filter was still attached plugged with silicone also. The top was stuck on the stand pipe - the o-ring that seals it was coated with silicone making it hard to remove. I left the bucket in the full extended position while I cleaned the tank and attached parts then installed the sump screen and lowered the bucked and drained that fluid and checked for more debris. It was clean. I removed the nail inserted in the bypass and had to clean silicone out of it then checked for freedom of movement and it seemed ok. Assembled everything - filled and checked the operation and it works great. That's when I discovered the rubber injector return tees were leaking so the saga continues. I'm inspecting the rest of the machine for signs of silicone. I'm thinking while I replace the tees on the return that I might pull the injectors and have them popped for pressure. They are old and since I've gone this far with the service I might as well check them and I may just break down and replace them anyway.
 
You're likely to ruin them just getting them out unless they were installed with Never-Seez. If you DO get them out and pop test them - do not let anybody try to turn them up to factory specs. Used injectors are not supposed to open at the same high pressure as new ones. You can buy brand new ones for $35-$40 each if you shop around. I'd be more concerned about the injection pump. If you have a "C" model - it's obsolete and cannot be rebuilt. If you have a DB or JDB model - it's likely to have now, or soon, a shattered vibration damper in the governor. Major fail part. Can be updated and that pellathane/plastic ring eliminated.
 
Besides the injection pump - one more thing you ought to check. The two nuts (on top) and two bolts (on the bottom) that hold the hydraulic reverser to the transmission case. Another major failure area. If any are loose the cases get ruined, as do the shafts, side frames, steering clutch housings, etc. It's a major reason for many 350s to get scrapped for parts.
 
Yes - I don't want the higher end on the injectors because of the load on the pump. I am looking for consistent pop pressure at the lower PSI. Mine is a straight 350 with Roosa Master pump which I believe is the only pump supplied? I assume it is a later model since is has the cyl liner seals installed on the liners rather than in the block. The S/n as best I can get it is 24094. It would be nice to know what to do in case the pump ever becomes an issue. I did an in-frame about 8 years ago and I did use the Never-Seez on the injectors when I installed them in the head I had rebuilt. I did come across 2 brand new pump return line fittings with the glass balls that go on top of the pump if I ever need them. Since the loader is only used once in a while I mainly paid attention to the fluid levels and engine service. Since the pump is rotary design I never gave much thought to problems. If parts are available I will probably gather up what I can in case I ever need them.
 
The early engines had only one black o-ring on each sleeve and no grooves in the block. The "upgrade" replacement sleeves come with two extra grooves on each sleeve so in all - there are three seals per sleeve. Later engines come with two grooves in the block per hole and no grooves on the sleeves.
The injection pump are all rotary-distributor. USA versions only use Stanadyne/Roosamaster. German versions use Rotodiesel. With the Standyne/Roosamaster - there are two basic pump models. C and D. Technically "Cs" come as CDC or CBC and are cannot be rebuilt. The "Ds" come as DBG or JDB and all parts are still available for them.
If you have a DBB or JDB pump - there is a plastic (pellathane) vibration damper that always breaks. Just a matter of when. A C pump does not have any of that plastic but NO rebuilt parts are available for it if something fails. All D pumps built after 1985 intended for highway use have the plastic eliminated like on Ford and GM pickup trucks with 6.2 and 7.3 diesels. The same can be done for older D pumps on Deere tractors if wanted. A simple check if you have a D pump is to remove the little rectangle timing window from the side and see if it's clean in there. If a plastic dampener has come apart -that area will be full of bits that look like mouse turds. A complete seal kit for the D pump with a new plastic dampener is $15. A new housing-pressure-regulator-valve (fitting with the ball) is $7. The part to upgrade the pump and eliminate the plastic is $50.
 
I guess I had the liner info wrong. Mine is the earlier with seals on the liners... built in 1966. My fuel pump does have the plate you described held on with 2 screws. I removed it and the inside was clean - so I guess I'm lucky. I ordered an upgrade kit and I'll keep it back until fall and install it then. I intend to use it maybe 40 hours at the most so I'll keep an eye on it. I know how plastic breaks down with time. Since it is a holiday weekend nothing was open so I made my own return for the injectors. I'll pull them this fall when I service the pump. Fired her up and she purrs like a kitten. I did get the back box flushed and filled and replaced the gear oil in the finals. I ran her around the farm for about an hour to check everything and to my surprise no leaks. I want to thank you again for your help. I think the pump job will be pretty straight forward since I remember most of the steps from rebuilding Rossa flower head pumps on Mack engines back in the 70's. However - when I get to that stage this fall I'm sure I will run into something again and need advice.
 

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