353 HST shuts off for no apparent reason

[tpcannon]

If your oil pressure switch doesn't solve the issue, go ahead and replace the fuel cutoff solenoid.
I have a 2014 T353 that had the same issue, which started intermittently when it only had 20hrs on it and got a lot worse over the next 40 hrs. Two different dealers couldn't figure it out because they would never run it long enough to get it to working temp where the failure would occur. I raised **** directly with Tym warranty when the dealers were wasting my time and gas, talked to their service manager who sent me a new solenoid to install. It's been stall free for a couple years now.

It turns out from the schematic that the solenoid used this engine has two coils, one electromagetizes to draw the solenoid plunger back to start, and the second coil then electromagnetizes to keep it back (and engine running) when the other cuts off after a few seconds of running. It was this second one that went bad on mine, so initially the solenoid would clack and kill the engine after about 2-3 hrs of work, but got worse and more frequent over time and several trips to the dealers for diagnosis. After the initial stall which was usually 2-3 hrs in, it would restart right back up again each time only to cut back off after the few seconds when the solenoid switched from the start coil to the run coil. It would do this then endlessly until you let it sit for 30 min to cool down.

If yours is in warranty have the dealer replace it, if not I've seen them online for $75. Hope this helps and hope you have good luck solving the issue

Thanks! This is interesting because the dealer also suggested that the solenoid itself might be the problem.

So far, I replaced the oil pressure sw (dealer's first guess). I gave it a fresh oil change, filter and fuel filter cartridge. Then I started it up and worked it for about 20 minutes or so with the box scraper. Heard the *clack* and it shut down. Started right back up. I let it idle for a few moments, brought the revs up and hit the forward pedal and it shut down. Did the same procedure with the reverse pedal and it shut down. So now I'm suspecting something with the HST.

It is just about due for a tranny oil and filter change, but it isn't overdue. I know there is a switch somewhere on the HST but I don't know where it is.

I have a message in to the dealer's service department. I may try the solenoid on suspicion anyhow. I know that for the last couple of winters, it would shut down on me after 2-3 hours of snow removal. I could restart it and it might shut down again a minute later, but eventually, it would start and I could continue working until I was done - sometimes another hour or so. That was what made me think it was a problem with the seat switch going flaky.

But those initial symptoms I had sound identical to yours, so it could be that solenoid. Maybe my experience yesterday with the HST pedals was coincidence, or something else?

Thanks again. I'm so grateful for all the help on this forum!

 

[tpcannon]

If yours is in warranty have the dealer replace it, if not I've seen them online for $75. Hope this helps and hope you have good luck solving the issue

I'm definitely not in warranty. Do you have the part number by any chance?

 

[BlueMarlin]

The part number used for mine is 30A87-00040, which fits the Mitsubishi S4L2 and S3L2 engines, I would think yours should be the same engine. Starting in 2015 they put tier 4 Yanmar engines in them and called them T354.

If you swap it out it's a pretty easy install, be sure to mark how far the old one is threaded into the housing and replicate that distance on the new one. You'll need a small tube of gasket maker fuel resistant rtv silicone like permatex to seal the threads when installing the new one to the housing.

 

[tpcannon]

The part number used for mine is 30A87-00040, which fits the Mitsubishi S4L2 and S3L2 engines, I would think yours should be the same engine. Starting in 2015 they put tier 4 Yanmar engines in them and called them T354.

If you swap it out it's a pretty easy install, be sure to mark how far the old one is threaded into the housing and replicate that distance on the new one. You'll need a small tube of gasket maker fuel resistant rtv silicone like permatex to seal the threads when installing the new one to the housing.

Thanks! Yes, I have the Mitsubishi S4L2 engine and that is the solenoid I ordered. Great advice on marking the old one. I did that. Here's the rest of the story so far.

I ordered a new shut off solenoid. Got it Friday. Saturday morning, I removed the old one and attempted to install the new one but there is a machining error with the threads and it simply wouldn't go more than a quarter turn.

I took the nut off the old one and put it on the new one and it went on but was very hard to turn.

Took the nut off the new one and put it on the old one and it went right on, as it should.

So, I've ordered another one, I'm returning this one and maybe next weekend I'll get to try this again.

In searching for the part number for the solenoid, I found some good reference material.

Engine service manual from TYM with Mitsubishi S4L and S4L2:
http://tym-mitsubishi.ru/booklets/Mitsubishi SL series ServiceManual.pdf

Parts Catalog for Tym T303/T353NH and HST
https://static1.squarespace.com/sta...1adda9a1d015/1483141153350/T303+T353+NHEU.pdf

 

[thepumpguysc]

Theres are pretty "complicated" instructions in the manual on how to install the solenoid..
Theres also an "easy way"..
Once your happy w/ the threads on the new solenoid..
Keep it backed out alittle & unhooked... start the machine & slowly screw it in, until the engine dies.. NOW lock it down.. DONE.

 

[tpcannon]

Theres are pretty "complicated" instructions in the manual on how to install the solenoid..
Theres also an "easy way"..
Once your happy w/ the threads on the new solenoid..
Keep it backed out alittle & unhooked... start the machine & slowly screw it in, until the engine dies.. NOW lock it down.. DONE.

I used a dial depth gauge to determine how far the old one was screwed in. Then I set the nut on the new one at that exact depth and screwed it in and cinched the nut. The original had flat surfaces to get a wrench on the solenoid body. The new one doesn't So I used the nut from the old one to back-up the nut on the new one.

It starts and runs, but unfortunately, the symptoms are still there. Ran the tractor for about 15 minutes attempting to take some erosion out of my driveway and *clunk* - shut down.

 

[tpcannon]

Just to catch up on this. The first solenoid I ordered took a week to get but the threads were defective and it wouldn't install. Returned it for refund and simultaneously ordered another new one. Took a week for that one to get here and when I unboxed it, there was greasy dirt in the threads as though someone had tried it and returned it for some reason. May have been just fine, but I decided to return that one without trying it. I ordered a third one and receive that one Thursday afternoon. Installed it Friday morning, but didn't have time to test the tractor.

I had a couple hours clear this afternoon, so I started it up and after a short warm-up, I started using it to take some erosion out of my driveway. Ran for about 15 minutes or so and *clunk* & shut down. I waited about 30 seconds and started it back up. My scraper blade was still down, so I pushed some road base backwards about 70 feet and it shut down again. I started it back up, raised the blade, and backed it another 100 feet or so into the garage where it sits.

The Check light started coming on intermittently after I had the tractor warmed up and working. It comes on and goes right back off but this hint must be something to do with what is shutting the solenoid off. Oil pressure switch is new, fresh oil and filter are installed. The troubleshooting sections in the operator and shop manuals have nothing about this trouble. There is one chart that shows an HST switch, but the dealer says there is no HST switch.

I'm frustrated beyond words at this point. According to the book, there are several switches that can open that circuit to cause that shut-off solenoid to prevent the engine from starting. The two that I first suspected - the seat switch and the engine oil pressure switch did not fix the problem. The engine temp has a gauge and the engine is running nice and cool according to the gauge.

 

[thepumpguysc]

If your REALLY frustrated.. run a hot wire off a toggle switch.. up to run, down to shutoff..

 

[tpcannon]

If your REALLY frustrated.. run a hot wire off a toggle switch.. up to run, down to shutoff..

Trust me, I've actually considered that.

These safety features are great when they work, but at this point, I have no way of knowing whether or not this is working as designed or if it is a bad ground somewhere.

 

[tpcannon]

Does anyone know what model Eaton HST this tractor uses? Is there a temperature sensor somewhere on the transmission? The reason I'm asking this is because I realized that I've never had the problem when the tractor was just sitting and idling. It always presents itself when the tractor is being used and only then when the transmission should have had time to warm up to normal working temp. If there is such a sensor, maybe it has a problem OR maybe the HST is getting too hot for some reason?