Water in hydraulic system

[FrankenCub]

I went out to plow my driveway with my 154 yesterday and the hydraulics would not work. No noise at all from the pump and it didn't feel like it was getting warm from the pump running. Pulled the intake line and seen there was no fluid in it so I put a heater under the transmission for an hour. Still nothing so I put my heat gun at the filter for a bit and it all came to life. Same thing this morning, less than a minute on the filter and all was good.

So here's my question, short of spending a couple hundred $$ in new hydraulic fluid to flush the whole system, is there an additive I can add to the system or something else I can flush it with ?
I just drained and replaced the hydraulic fluid and new filter this summer. It wasn't HyTran though, was NAPA equivalent. I couldn't afford the HyTran at the time.

[Boss Hog]

I do not think it would have froze with the Hy Tran in it, Hy Tran mixes with water , the same as Hy Tran does not I guess

[Eugene]

Tighten the hydraulic oil filter another 1/2 turn. If that doesn't work, replace the filter. Thinking the hydraulic system is sucking air at the gasket when really cold.

Filter is on the suction side, feeding the hydraulic pump. If there were water in the system and froze up, you wouldn't have thawed out the system at the oil filter.

[FrankenCub]

I do not think it would have froze with the Hy Tran in it, Hy Tran mixes with water , the same as Hy Tran does not I guess

That's what I thought, it did look kinda milky like water was mixed in. But ......

Tighten the hydraulic oil filter another 1/2 turn. If that doesn't work, replace the filter. Thinking the hydraulic system is sucking air at the gasket when really cold.

Filter is on the suction side, feeding the hydraulic pump. If there were water in the system and froze up, you wouldn't have thawed out the system at the oil filter.

You make a good point, what looks to me as a milky mixture could be aeration. I will try tightening the filter tomorrow. Although this weekend is the first I've had an issue with it, it was in the 20's. Previously it was single digits when I used the carry-all to bring fire wood from my shed to the deck and it worked fine. I was thinking the filter could have froze/gelled because it's not really much mass and easily cooled.
That heat gun will get wicked hot though, can start a piece of wood on fire with it. Hopefully the temperature changes loosened it up enough to suck air :crossesfingers:

[SONNY]

Before you try to turn filter,--might be good idea to warm it up with the heater to soften the gasket a little! thanks; sonny