# S1 cartridge valve



## Dirtrider335 (Dec 30, 2019)

Hello All, awesome site you have here ! Anyway I have anew to me Unimount Midweight with a Flostat hydro. My issue is, it will quit working intermittently. No lift or down. When I hit the raise, the blade goes left. I can hear the solenoid click on down, but no movement. I am leaning towards the S1 valve. Oil is fresh, I didn't pull any check valves. What are your thoughts?


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## cwren2472 (Aug 15, 2014)

Is it up in the air now? If so, how did it get there if it wouldn't lift?


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## Dirtrider335 (Dec 30, 2019)

The first time it happened it was on the ground. drove back to the shop and backed it in. That's when I changed oil again and did my testing. the two times since it has quit in the air. last night I was running down the highway, temp gauge was getting a little high so I swung the blade out to let more air in, touch the down button and the plow dropped. Used the truck for about 20 min this morning before it quit again.


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## dieselss (Jan 3, 2008)

Did you ck for power and magnetism on the coil?


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## cwren2472 (Aug 15, 2014)

If it won't raise or lower, you have multiple issues. I'll wager even money it is the 3 pin control harness, not the valves.


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## Philbilly2 (Aug 25, 2007)

I am guessing you need to clean and tighten up the pins on the 9 pin grill connector. Next time it does this, go wiggle the 9 pin connector and try it again. (May take a few times to get the right connection)((watch your toes if the plow is in the air))

The blade going left when you hit raise is typically a S2 that is stuck... 

The fact that it stays in the air says that the S1 is shifting back to the "closed position" if the S1 was not shifting back, the plow would drop to the ground as soon as you let go of the controller.


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## cwren2472 (Aug 15, 2014)

Philbilly2 said:


> I am guessing you need to clean and tighten up the pins on the 9 pin grill connector. Next time it does this, go wiggle the 9 pin connector and try it again. .


"FloStat" if I know my Western terminology right should be a 3 plug.


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## Philbilly2 (Aug 25, 2007)

cwren2472 said:


> "FloStat" if I know my Western terminology right should be a 3 plug.


Valid point, missed that... I sit corrected on the 9 pin, it would be the 3 pin as stated...

BUT... Unimounts did not come with flostat, Unimounts came with isarmatic units...

so is it a Ultramount then? or a converted Unimount?


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## Dirtrider335 (Dec 30, 2019)

I have power to all of the coils. It is a 3 pin connector. The S1 stem is a little tight on the coil. was thinking if the check ball in S1 is stuck when raise button pushed thats why it goes left ???


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## Philbilly2 (Aug 25, 2007)

Dirtrider335 said:


> I have power to all of the coils. It is a 3 pin connector. The S1 stem is a little tight on the coil. was thinking if the check ball in S1 is stuck when raise button pushed thats why it goes left ???


S1 is only for lower/ float you already said that the blade will stay in the air, so their is not anything wrong with your S1. If S1 was stuck, as soon as you let go of raise, the blade with drop.

If you have an issue with a poppet valve, you have an issue with the S2. If you ask for raise and you get left, the S2 could be stuck in the shifted position. But if your plow does in fact lower... it is not stuck. Fluid needs to pass through S2 to lower plow. So if you have an on again off again with the plow going to the left when you request raise, and you are sure that you have 12v+ at your coils, start with S2.


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## Dirtrider335 (Dec 30, 2019)

On the raise flow chart fluid on rasie goes through S1 check valve


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## cwren2472 (Aug 15, 2014)

Dirtrider335 said:


> On the raise flow chart fluid on rasie goes through S1 check valve


That's true. But a problem with that valve would not cause the fluid to get to the angle cylinder instead. The S2 valve being stuck _would_ cause that as @Philbilly2 said.


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## dieselss (Jan 3, 2008)

Lower and raise


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## Philbilly2 (Aug 25, 2007)

This... S2 is in the "non energized" position in this diagram

See how if your S2 was stuck in the shifted position, the plow would not lower, and it would not let the fluid go to the lift ram if you asked for "raise" on your controller.


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## Philbilly2 (Aug 25, 2007)

Dirtrider335 said:


> On the raise flow chart fluid on rasie goes through S1 check valve





cwren2472 said:


> That's true. But a problem with that valve would not cause the fluid to get to the angle cylinder instead. The S2 valve being stuck _would_ cause that as @Philbilly2 said.


Kinda true, it does go threw the S1... after it passes threw the S2... after it passes threw the S3 though.

Question is what position each of the valves is in is the reaction that you get from the plow at that time. All need to be in the correct position or the fluid cannot make it to the S1 to lift or lower the plow.

Raise is the second flow chart that DieselSS posted.


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## Dirtrider335 (Dec 30, 2019)

I'm picking up S1 & S2 valves late this afternoon. 1 because of the swollen stem & s2 from your advice. Hopefully I will get time to work on it tonight. I will post results then. Thank You everyone for your input. G.


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## Philbilly2 (Aug 25, 2007)

Dirtrider335 said:


> swollen stem


 a what?


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## Dirtrider335 (Dec 30, 2019)

Philbilly2 said:


> a what?


Solenoid coil stuck/tight to cartridge valve stem. I read somewhere that those needed to be replaced.


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## Dirtrider335 (Dec 30, 2019)

Ok, you guys know yer **** !! Or at least Western Snow plows ! Thank you very much! I installed new S1 valve. Tried the down switch, it moved just a touch. Probably from fluid loss when changing out the valve. Installed S2 valve every thing works !! I'm going out to use it now. If I have any problems I'll post it. Cheers to all !


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## Philbilly2 (Aug 25, 2007)

Dirtrider335 said:


> Ok, you guys know yer **** !! Or at least Western Snow plows ! Thank you very much! I installed new S1 valve. Tried the down switch, it moved just a touch. Probably from fluid loss when changing out the valve. Installed S2 valve every thing works !! I'm going out to use it now. If I have any problems I'll post it. Cheers to all !


Glad to hear you got it fixed


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## Dirtebiker (Nov 10, 2016)

Philbilly2 said:


> Valid point, missed that... I sit corrected on the 9 pin, it would be the 3 pin as stated...
> 
> BUT... Unimounts did not come with flostat, Unimounts came with isarmatic units...
> 
> so is it a Ultramount then? or a converted Unimount?


My Unimount MVP has the Flostat side by side motor/reservoir. Is this an oddball?


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## Philbilly2 (Aug 25, 2007)

Dirtebiker said:


> My Unimount MVP has the Flostat side by side motor/reservoir. Is this an oddball?


That is normal.


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## Dirtrider335 (Dec 30, 2019)

I did bench test S2 valve. The piston did move but I couldn't see that it wasn't closing. Maybe if I would have compaired the new to old I would have noticed. Plowed for a couple hours last night. No issues. It's always good to learn something new !! Thanks again Guy's.


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