Trojan Boat Forum

I have a 1989 International and I believe I need to add fluid to the system. I see a small cylinder with a small pump to pressurize system at the back of the boat. The fluid can be seen through the site glass and is below minimum. How do you add fluid to this system? Thank you!

Relieve the pressure like you would a tire then remove the cap(1" ?) that the air valve is on and fill there . A bike pump works well to pressurizer the system

So I can see how to relieve the pressure but don’t see any fill cap. Only think on the top is the small pump to add pressure????

fourreins wrote: ↑Sun Jul 05, 2020 9:15 pm So I can see how to relieve the pressure but don’t see any fill cap. Only think on the top is the small pump to add pressure????

I don't recall a pump on any hynautic . The fill plug is below the valve you relive pressure ad air , photo of your tank ? here's one a little different then mine fill is circled in green

Did some checking the ones with the pump , you unscrew the pump to fill .

I tried to unscrew the nut under the black pump and got nervous because it seemed real tight and I didn’t want to break it.

That is the fill . But you could fill it where the gauge is , it would be a slow fill .

Thank you for all your help. I’ll take another look next time I’m at the boat.

Well I was able to unscrew the nut under the small black knob pump.... definitely the fill. Thank you!

Glad you got it . Thanks for the up date !

I just had to have my helm pump rebuilt and in the process I was able to obtain hynautic manuals. This is the place I sent my pump and you can find a lot of useful information here.
http://www.boaterstore.com/hynautics/hynautic1.html