I have a 2003 F150 supercrew 4x4 and I'm on my 3rd - 4wd vacuum actuator this winter so far.
somehow water is getting into the actuator itself mounted on the axle and then when it gets cold enough it freezes up and won't work until the heat from the engine thaws it out and then the 4x4 will engage.
everytime I've changed it I have found the part to have about a quarter cup of water in it. and can't figure out where the water may be entering these things.
there also was no moisture in the vacuum lines when I blew them out.


I've been using the Dorman brand replacements from O'Reilly, they have a lifetime quarantee but I'm sick of swapping them out every month... has anyone else had the same bad luck with the Dorman 600-300 actuator?
They are about a third of the price of one from the dealership.


Thanks for your time.

 

In 226,000 miles never had that issue with original actuator.
There are aftermarket parts not designed to OEM specs to the point they will cause an issue.
.
One example is the master cylinder pressure sensor switch from one source vended by a well know aftermarket parts store.
Tried 2 with the same results. They were actually 'to sensitive' and operated when they should not have.
Original Ford part fixed the issue.
.
Another example is the DPFE sensor. The specs for this part is very tight.
Another issue with vehicles that have air suspension has, is the air pump dryer gets water logged sending water logged air into the bags.
This freezes in cold temps.
Still another is the door lock motors cover boots deteriorate and let water in then freezes the motor fast until the cab heats enough..
.
Be sure to check on the possibility of water getting in at the firewall solenoid and running down to the actuator through the hose.
Better you replace with a Ford parts and end the hassle.
Your experience with the aftermarket part is of value to others.
Let us know how it works out and anything else you find.
Thanks for posting.
Good luck.

 

thanks for the reply...yeah I've been thinking just the same, bite the bullet and get the OEM part..I think ford guarantees their parts for 2 years anyways...I've got a little more than 220000 km's (about 138000 miles) on the truck and never had a problem until this winter with the 4wd...guess you get what you pay for...I just wondered if anyone else had the dorman part fail such as I have,
no water around the 2 solenoids on the fire wall..it has good vacuum on both lines.
I changed 2 in the last 3 weeks and both full of water.
....on the other subject I do have the door lock freeze problem on the rear passenger ...door lock...wont lock or unlock when until the cab warms up.

 

The door lock motors are actually reversible DC motors that turn a very fast spiral to pull and push a rod connected to the lock mechanism.
They have a boot to seal out water.
If water gets in it can't get out and freezes the motor up.
Good luck.