On most vehicles with rear drum brakes, the star wheel is adjusted when you back up and step on the brakes while reversing--a system of cables and levers turns the wheel ever so slightly, and this is supposed to keep them in adjustment. Adjustment is necessary on these rear-drum vehicles because normal braking wears out the brake shoes and drum, creating more clearance between the shoes/drums and thus requiring something to take up that clearance.

HOWEVER, on expeditions with rear disc brakes, the parking brake shoes are located inside the disc and do not work as service brakes at all; they are only used as parking brakes. They should never touch the 'drum' portion of the rear discs when the discs are turning (unless the parking brake is pressed into service as an emergency brake). Thus, there should never be any rotational friction on the parking brake shoes...thus the parking brake shoes and parking brake 'drum' part of the disc should never wear...thus there should never be a need for adjustment. I suspect that the need for adjustment comes from a gradual lengthening of the parking brake cable--which will only stretch a finite amount. So once you adjust the parking brake once, after accomodating the cable stretch, you should never have to do it again.

 

Hi All, new to this forum. Well, I adjusted the star gear as far as it will go and the back wheels still do not lock up. When parking brake pedal is totally mashed to the floor the wheels do lock up. Way more effort then I feel is needed. I havent checked, but Im guessing my pads may be a wee wore out or is there possibly something else is wrong?

 

Hello, I'm new to the forum but not mechanics and especially not Ford trucks. Yesterday I replaced the rear axle seal in my 99 Exp. I found that my P-brake shoes were completely worn out to the metal. I drive an F-250 but this vehicle is driven by my wife and son. One of them must have driven with the p-brake on (yet neither will admit it). Also the adjustment on p-brake is completely manual. I had the whole system apart there are no automatic adjusters. You may want to look and the back of the backing plate and make sure that the cables are moving on both wheels. Your cable could be rusted and broken inside the casing, and the rust could cause increased force to apply pedal. Hope this helps and thanks for having me.

 

I have a 00 expedition with the rear disc bakes & my parking brake pedal goes very low. It grabs but not like it should as stated in the earlier post. How do I adjust the parking brake on a disc brake set up?

 

Even though you have disk brakes, your p-brakes are shoes inside of the back of the rotor. The center of the rotor acts like a drum. Follow the instructions given by tsdrallyer on 10-18-03 @3:49 p.m. on this thread to adjust those shoes.

 

I looked at that post, wasn't that talking about adjusting drum brakes? It mentioned a backing plate & the rubber plug. If not then I am lost???

Are you saying that the brade pads do not work with the rear parking brake? I'm pretty sure that the cable causes the rear calipers to extend outward so the pads can grip the rotors, No?

 

It originally was asking about adjusting the parking brake (on an Expy?).

Correct. The brake PADS work with the service brake, not the parking brake.

No. The cables cause two small brake SHOES to expand inside the 'hat' of the rear rotors. The 'hat' funtions as the drum for the parking brakes' SHOES. These shoes can be adjusted out like you would adjust the shoes of a drum service brake.

The discussion seems to now be centered around if these shoes are automatically adjusted when you apply them in reverse (similar to a drum service brake system, or if they have an automatic star wheel adjuster that keeps them adjusted when ever the parking brake is applied, or if there is an adjustment on the cables.

I think some forget that this is an Expy/Navi board, not the F-150 board.

 

OK, thanks for explaining this further. I will have to look at the calipers & see if I can locate the star adjuster thingy. Yes, it is a expedition.

 

I recently had to adjust the parking brakes on my 2013 Expedition. It is a manual process with an adjustment bolt gear located inside the rear disc brake.

As described previously, the parking brakes are "drum" brakes that operate inside the rotor disc hub. When the parking brake cable is under tension, it causes the parking brake shoes to grab the inside of the rotor hub. There is an adjustment bolt that can be turned to increase the spread of the two parking brake shoes and it has a gear on it to allow it to be turned with a screwdriver. This is the "star" adjustment referred to by others previously in this post.

Keep in mind that increasing tension on the adjustment bolt works OPPOSITE for the left and right hand sides. On Driver's side, push gear wheel "UP" to spread the shoes (i.e. tighten the brake) and on the Passenger side, push the gear wheel "DOWN".

This adjustment gear can be accessed from behind the rotor assembly and is easy to get to with the wheel removed.

Here are a few pictures:


Driver's side rear axle into wheel hub




Close Up of the Adjustment Bolt Access Hole Cover

The adjustment bolt can be seen after removing the rubber grommet cover (sorry...didn't get a picture of it).

This is the adjustment process I performed:

1. Block front wheels;
2. Raise rear of vehicle and support with jacks;
3. Remove Rear Tires;
4. Release parking brake;
5. Turn each rear wheel hub to get sense of "freewheel" resistance;
6. Apply Parking Brake;
7. Turn each rear wheel hub and see if wheels can still move freely with brake applied. If Yes, go to step 8 otherwise STOP - no adjustment needed.
8. Release Parking Brake;
9. Use screwdriver to turn brake adjusting bolt gear on driver's side "UP" 5 times to increase tension on brake pads. Each turn will cause adjustment gear to click.
10. Apply parking brake;
11. Turn driver's side wheel hub and determine change in resistance from initial condition in Step 7. If wheel can still spin, go to Step 12. If wheel is firmly held by parking brake, go to Step 13.
12. Repeat steps 8-11 until wheel hub cannot turn when parking brake is applied. Note that fewer than 5 turns of the adjustment gear may be required for each repetition to achieve the desired result;
13. Release parking brake;
14. Insure free travel of wheel hub. If wheel hub is not as free as in Step 5, adjustment bolt may need to be loosened to prevent unintended parking brake engagement when brake is released.
15. Repeat steps 9-14 for Passenger side except move parking brake adjusting bolt gear "DOWN" to increase brake tension.

Hope this helped.

 

Perhaps on a 2012 but this forum only covers through 2006 model years and that access to the adjuster is not available.

 

MY BAD! I posted this in the wrong forum....

 

Too bad, it was such a nice post.