Need help rear brakes!

[nitro71]

I'm still trouble shooting the intermittant pull to the left(drivers side). I had replaced the rear brake shoes recently after purchasing the X. I can't remember when the pulling problem started.

Is one of the shoes thicker than the other one? If so which way should this shoe be orientated? Front? Rear? I just checked my manual and all the springs and connections look correct.

I do have uneven wear comparing the driver to passengers side. I also have a small seal leak on the drivers side shaft bearing.

I understand there are 9" and 8" rear brakes. How do you differ between the two and what vehicles would they have come on?

I'm tempted to put new shoes and drums on the rear.

 

[Tony H]

one of the shoes will have more braking material on it. That one should face the rear of the vehicle. Emergency brake Shoe. I better check that..might be the front
I can't imagine the 'X' had 8" brakes. I thought they were all 10". The Drum will have the dimensions on it.
After install, tighten the rears until they rub the shoes.

 

[Carguy3J]

I'm still trouble shooting the intermittant pull to the left(drivers side). I had replaced the rear brake shoes recently after purchasing the X. I can't remember when the pulling problem started.

Is one of the shoes thicker than the other one? If so which way should this shoe be orientated? Front? Rear? I just checked my manual and all the springs and connections look correct.

I do have uneven wear comparing the driver to passengers side. I also have a small seal leak on the drivers side shaft bearing.

I understand there are 9" and 8" rear brakes. How do you differ between the two and what vehicles would they have come on?

I'm tempted to put new shoes and drums on the rear.

Uneven wear could indicate a failing wheel cylinder. If you're doing the brakes anyway, it might be a good iea to change them. They're cheap, and other than having to bleed the brakes, it's a very quick and simple thing to do.
Of course, uneven wear could also be improperly adjusted brakes and/or a non-functioning or malfunction self-adjust mechanism. That's why I like to also replace all the springs/adjuster/hardware whenever I do drum brakes.

Size (8" or 9") refers to the inside diameter of the drum. I don't know the breakdown of what determined what size you would have had. Generally, when a vehicle has multiple brake options like that, the bigger the engine, or heavier the payload capacity, the bigger the brakes. In any case, just measure your old ones to find out. As long as you change everything (shoes/hardware/drums/wheel cylinders), you can probably just put the 9" on anyway. (The backing plate might be different, not sure)

As far as your leak, that could definitely be a part of the problem. Gear oil and brake shoe friction material don't get along very well. If you have gear oil leak on one side, and contaminating the brakes, then that side would likely have reduced braking. Once they are contaminated like that, you can't clean them. You'll need to replace BOTH SIDES.

So, I would suggest that you do a complete rear brake job (including the wheel cylinders and hardware) and repair that leaking axle seal (or you might just ruin the new shoes), and be sure to adjust them properly, and evenly.

Also, back to your question on the orientation of the shoes. Each side will have a short friction material and a long one. The longer one goes to the back of the vehicle.

 

[Carguy3J]

that's backwards

one of the shoes will have more brakeing material on it. That one should face the front of the vehicle. Emergency brake Shoe.
I can't imagine the 'X' had 8" brakes. I thought they were all 10". The Drum will have the dimensions on it.
After install, tighten the raers until they rub the shoes.

The shoe with more material should go towards the REAR. This is due to what is called a servo effect. When the rear braked are applied, the front shoe contacts the rotating drum,the whole "brake assembly" "rolls" forward. This then "drives" the rear shoe harder into the drum. This makes the rear shoe work harder, thus the need for more friction material.

On the size point, I think you're right. RockAuto only list 10"X2.5" rear brakes for a '93 Explorer.

 

[nitro71]

Thanks for the info!

I do have the thicker pads to the rear on both sides. Both rear cylinders have been replaced.

The leak is on the drivers side which is the side it is pulling towards so it doesn't seem as if that could be a factor.

There is about 1/8" of play, in and out on the drivers side rear axle. I wonder if this could affect braking? The passenger side rear axle has no play in or out on it.

The front calipers and pads have been replaced. The whole system has been bled multiple times. I have also replaced the HCU, ABS unit, with a junkyard one. Replaced the passenger side brake hose. I've also had it aligned more than a few times. Replaced the RA bushings. The intermittant pull is exactly the same.

What type of adjusting is required? I had just let the rear adjusters adjust out.

 

[Tony H]

The shoe with more material should go towards the REAR. This is due to what is called a servo effect. When the rear braked are applied, the front shoe contacts the rotating drum,the whole "brake assembly" "rolls" forward. This then "drives" the rear shoe harder into the drum. This makes the rear shoe work harder, thus the need for more friction material.

On the size point, I think you're right. RockAuto only list 10"X2.5" rear brakes for a '93 Explorer.

A minute after I posted... I went back and checked and edited my post...

 

[nitro71]

Toss out any ideas. This brake thing is making me crazy.

It's about 20 degrees out or I would probably do the seal. But as I don't think it could be making it pull to that side I'm hesitant to fix it this time of year.

I looked at the shoes again. The wear is almost identical from passenger to driver side shoes. I can't see anything wrong.

I'm thinking the rears are not the problem.

 

[Tony H]

Did I miss something? I didn't read where you had an axle seal leak. If you do... you will mess up the new shoes in no time.

Yeah man it's windy and cold here in NY
"Intermittent pulling"
do you mean it pulls some days but not others or do you mean it pulls first thing in the morning but as you drive it the pulling stops??

 

[Carguy3J]

Toss out any ideas. This brake thing is making me crazy.

It's about 20 degrees out or I would probably do the seal. But as I don't think it could be making it pull to that side I'm hesitant to fix it this time of year.

Well, without being there, it's kinda tough to diagnose. You said you replaced the HCU/ABS with junkyard parts. Once ABS units get air in them, it can be very difficult to get it all out, some even require being connected to dealer service equioment to cycle all the valves while the system is being bled. Of course, since it is a junkyard part, it could just be bad. A stuck valve or something in the ABS unit could be reducing brake pressure to one or more wheels (front or rear).

If you're sure it's not the brakes, then I would start looking for loose/broken suspension parts. For example, a control arm that "wiggles" under braking loads, due to maybe a worn bushing, could make it pull to one side. Bad or worn sway bar bushings or end links can also do strange things. Under braking, the front attempts to dive. The sway bar should provide even side-to-side resistance to this weight transfer. If the bushings are bad, it can cause uneven/excessive weight transfer, which can also lead to undesired steering.

Bad wheel bearings (front or rear), as well as bad tie rods/ball joints could also lead to a intermittent "pull", especially under load/weight shift actions like braking.

 

[nitro71]

Drives side rear axle has a minor leak. I can see where it hasn't dripped to the shoe yet. Pull is to that side also. Doesn't seem like it could cause it to pull to that side.

 

[nitro71]

I'll take a look at those sway bar connections. I had them apart earlier this year. Could be I've created my own problem somewhere along the way.

The passenger side front wheel bearing is a hair loose. I ran it tightened in one notch on the nut and it was making me nervouse about it being to tight. Perhaps this is part of the problem? We are talking very minimal movement on the tire but still detectable.

 

[nitro71]

One of the rear drums had a bit of uneven wear so I swapped them. No difference. Going back to looking into the front end for the problem.