2 questions. Trans flush and hyd pump seal.

Mon Oct 11, 2010 8:32 am

OK . . . So about a month ago I changed the tranny fluid in my 185. Yes, it had about 1/2 gallon of water in it. I also changed the coolant and engine oil/filter, it was dirty but looked OK then.

Coolant is fine, hasn't changed level any. Trans got milky but I expected that since it had a lot of water in it. But my engine oil soon turned milky and the level raised 1/2-3/4 of a quart. As far as i can tell, I have the small hyd pump, (Cessna I assume). I'm thinking the front seal on the pump is bad but it doesn't seem to be available as OEM.

1. What's a good way to flush all the gorilla snot out of the tranny/hyd?

2. Does it sound like a front hyd pump seal is bad?

3. Where can I get one, does it cross to an aftermarket?

THANKS ! ! !

Re: 2 questions. Trans flush and hyd pump seal.

Tue Oct 12, 2010 7:03 am

Bueller . . . . Bueller . . . . Bueller . . . . ? ? ?

Re: 2 questions. Trans flush and hyd pump seal.

Tue Oct 12, 2010 9:16 am

Have you tried Messick's Tractor?
They show a front pump seal #202996C91 being available for $9.26
They also show an O-Ring and gasket set #544024R91 or maybe #204287C1 for $40.33 (does not contain the front seal but has many other misc parts).

A couple of cans of dry gas (alcohol) added to the hydraulic fluid and run for a few hours before draining will help get the 'snot' off of everything. Do not leave it in long term though - it might hurt O-rings over long term.


Re: 2 questions. Trans flush and hyd pump seal.

Tue Oct 12, 2010 10:07 pm

If i wanted to flush the hyd system as completly as possible in one operation I would

1) first run the machine and warm it up well
2) place it in a position that all hydraulic cyls. are in the retracted position
3) drain the trans and reaxle as completly as possible
4) remove the return line from the top of the trans cover and route to a drain pan
5) Fill the trans with fresh fluid (I would remove the trans cover to do so to save time and you will have to add more before this process is over)
6)start the unit and run untill the fluid coming from the return line is clean then reattach the return line (remember to maintain the fluid level in the trans)
7)then remove the line from the hyd cylinder(s)(one at a time) and activate the circuit to extend the cylinder to purge the circuit until the fluid runs clean (repeat with all cylinders in the system)
8( reassemble and reseal everything, fill the sytem and run

You will more than likely have to drain and flush the system at least one more time but this is the way to remove as much contaminated fluid at once.

The only method more thorough would be to completly disassemble very component in the system and clean.

I would never recommend using an alcohol based product in an hydraulic system. (or a diesel fuel injection system)