Fordrunner
Registered User
I have 85 f350 with 6.9 idi, i was wandering what the steps were to replace it.
thermostat replacement
- Thread starter Fordrunner
- Start date
whiteboyslo
FNG
FoolhardyIDI
Full Access Member
Here is how Chilton's says to do it.
1.Disconnect both battery ground cables.
2.Drain the coolant to a point below the thermostat housing.
3.Remove the alternator and vacuum pump belts
4.Remove the alternator.
5.Remove the vacuum pump and bracket.
6.Remove all but the lowest vacuum pump/alternator mounting casting bolt.
7.Loosen the lowest bolt and pivot the casting outboard of the engine.
8.Remove the thermostat housing attaching bolts, bend the hose and lift the housing up and to one side.
9.Remove the thermostat and gasket.
10.Clean the thermostat housing and block surfaces thoroughly.
11.Coat a new gasket with waterproof sealer and position the gasket on the manifold outlet opening.
12.Install the thermostat in the manifold opening with the spring element end downward and the flange positioned in the recess in the manifold.
13.Place the outlet housing into position and install the bolts. Torque the bolts to 20 ft. lbs.
14.Reposition the casting.
15.Install the vacuum pump and bracket.
16.Install the alternator.
17.Adjust the drive belts.
18.Fill and bleed the cooling system.
19.Connect both battery cables
1.Disconnect both battery ground cables.
2.Drain the coolant to a point below the thermostat housing.
3.Remove the alternator and vacuum pump belts
4.Remove the alternator.
5.Remove the vacuum pump and bracket.
6.Remove all but the lowest vacuum pump/alternator mounting casting bolt.
7.Loosen the lowest bolt and pivot the casting outboard of the engine.
8.Remove the thermostat housing attaching bolts, bend the hose and lift the housing up and to one side.
9.Remove the thermostat and gasket.
10.Clean the thermostat housing and block surfaces thoroughly.
11.Coat a new gasket with waterproof sealer and position the gasket on the manifold outlet opening.
12.Install the thermostat in the manifold opening with the spring element end downward and the flange positioned in the recess in the manifold.
13.Place the outlet housing into position and install the bolts. Torque the bolts to 20 ft. lbs.
14.Reposition the casting.
15.Install the vacuum pump and bracket.
16.Install the alternator.
17.Adjust the drive belts.
18.Fill and bleed the cooling system.
19.Connect both battery cables
Why are you replacing it?
Fordrunner
Registered User
its shot, have no heat
No heat in the cab, or the engine never gets up to temp?
Fordrunner
Registered User
no heat in the cab, i drive 140 miles a day with no heat
A thermostat isn't your issue...
If the engine gets up to temp, but you don't have heat in the cab, check the following:
- Does the hvac selector work? (floor, vent, etc) If not, check the vacuum lines running to the switch and actuators. The recirc actuator is under the hood, near the passenger side firewall and has a white vacuum line to it that often breaks.
- Does the hvac fan work, but only seems to blow cool air? Check the blend door. Drop the glove box and you will see the blend door cable. The ends can be damaged by cranking on the temperature knob.
- Does the heater core leak? Usually evident with wet spots on the passenger floor or coolant smell. Easy replacement if need be.
Fordrunner
Registered User
thanks ill check those out.
Don't know what year the t'stat neck was changed, the little check ball that riotwarrior refered to may be in the neck itself, just shack it to see if it rattles if it's there. Check ball is for air persion, it will seal when coolant reaches it.
Any luck diagnosing the lack of in-cab heat?
Fordrunner
Registered User
yes i did i checked the things that you had mentioned to check and they were all good. so i went ahead and replaced the thermostat anyway and that was the problem now it gets to hot in there.
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