a few ?

[biggish]

hey everybody, my 04 f350 drw lariet, truck has a few bugs just started here goes,
4 wheel drive quit working on auto light comes on no go,very little heat at idle and the hydro booster is making a god awfull sound which will give me very little brakes at times

so with the no heat im gonna check heater core hoses in morning if there good and hot is that good?
im also going to change my t-stat tomorrow as well it was changed last year for the same issue but here we go again did fix it for a while, what about the water pump how do i check it?

as for the four wheel drive any thoughts? where do i start my truck works hard everyday it has 300000 km on it has 4 inch turbo back,egr,cooler delete aem intake and have a hypertech in it stage 2
i will also change the hydro in the am again! also truck does not show signs of puking or loss of coolant and is full sorry about the long post just need good ideas and you guys rock!!!

[Goose350]

You more than likely have a leak in your hubs or vacuum lines. Does the 4x4 work when you lock the hubs?

[biggish]

yes it works when i lock it in, i changed the heater core and thermo and my hydro boost works good now i have heat like never before wow!! but in auto mode for the 4 by nothing the light comes on heat stops blowing from the floor for a few sec and will only blow defrost then com back to floor but no 4 by

[Goose350]

You have a leak in your vacuum lines. I would also check them to make sure they are connected.

[biggish]

were do i find all lines is there a diagram somewhere i could see thanks for the help