Trim cylinders bleeding down fast

[Chevyls6]

What would be the most likely cause of trim cylinders that dont stay pumped up?

 

[achris]

Bad valves in the pump, bad o-rings in the ram...

More info needed.

Chris...

 

[Chevyls6]

Bad valves in the pump, bad o-rings in the ram...

More info needed.

Chris...

So far i've gone through the trim pump and all the check valves seemed ok for the most part. Little bit of corrosion on some of them but not the one that holds pressure in the rams.

the cylinders havent been opened probably since new so i have no idea what they look like inside.

Whats a good substitute for the 20w MS oil the manual calls for? I currently have it filled with dex/merc atf since thats all i had.

 

[Scott06]

So far i've gone through the trim pump and all the check valves seemed ok for the most part. Little bit of corrosion on some of them but not the one that holds pressure in the rams.

the cylinders havent been opened probably since new so i have no idea what they look like inside.

Whats a good substitute for the 20w MS oil the manual calls for? I currently have it filled with dex/merc atf since thats all i had.

You can leave the atf in there as it will work fine

I think I got hydraulic oil with a ISO 32 rating at the local auto parts store that worked fine

 

[achris]

If I was starting from scratch with a trim system, I'd look very closely at a Shell oil called 'Tellus32'... But that is 100% not compatible with anything else. You'd need a completely clean system to start with.

Other than that ATF (Dexron II) or a non-detergent SAE30 oil works perfectly well.

Chris...

 

[Chevyls6]

Well i got it fixed. There was a blown out o ring in one of the cylinders.

Filled it with sae30 and it seems to be working well. The pump even sounds better with the thicker oil.