Rear shock air pressure problem

[Silverfern]

Hi, Firstly , im fairly new to mountain biking, and inexperienced with shock maintenance,

Just brought my first dually 3 or 4 weeks back, A trek rumblefish,

The shop set up the shock and fork to my body weight ,have been happy just to ride the bike and get the feel of it for now and have felt no need to touch the suspension,

On Sat I rode , and it felt very soft in the rear,when I got home checked what the psi should be for my weight( 190) checked the shock (150)so added air to 190,

Rode sunday, felt soft again, checked it when home, back to 150, added more to 190,

Havnt ridden since, its now monday , checked it again , its back to 150,

Im either doing something wrong( strong chance) , or im losing air ,i thought I would do some research first before contacting the LBS,

please give advice if you can , cheers

[PhxChem]

Some of the air is being lost just by attaching the pump to checking the pressure. Try this. Pump it back up to 190. Unscrew the pump. Now screw it back in. That will give you an idea of what is being lost just by checking the pressure.

[owtdorz]

Add 10 more psi than needed. That seems to be the average lost when removing the pump.

[Silverfern]

Thanks for your help , yeah I overlooked that due to inexperience. , also I wasnt aware of the need to cycle the shock to fill both chambers,

This weekend will be the test when I get to ride it again.