Welcome Visitor! Please take a few seconds and li7in6
Well-Known Member
- Joined
- Jul 21, 2009
- Messages
- 80
- Transmission
- Automatic
I was recently given a '96 B2300 with just shy of 200,000 miles on it. Mechanically sounds outside of seriously blown U-joints, pinion seal, O2 sensor, coil packs, and a few other odds and ends. After fixing it up its made a pretty reliable beat around truck for hauling stuff around spare one problem.
First time it happened I was helping someone move a few loads of stuff to their storage unit, just loaded up and was driving the 2 miles to the storage unit when I went to stop at a stop sign and the pedal went to the floor. Luckily it was a residential area so i wasn't going very fast, and I'm not a late braker so I had tome to react before rolling right into traffic. Downshifted, parking brake, and pulled over. Coasted it back to the house and took a look. Rear drivers side wheel had a puddle of brake fluid under it.
Took it apart and the adjuster dropped out as i pulled the drum off. I found the wheel cylinder's seal was blown and the lower spring (that pulls the shoe's together and puts tension on the adjuster was broken. I also found that the gold colored ramp that holds the cable that puts tension on the arm which engages the star adjuster had broken. The round indented part that centers the ramp in the hole in she brake shoe had partially sheered off and was no longer held in place, this removed all tension from the cable and allowed the star adjuster to spin freely. What I thought was a freak accident of both the adjuster tension spring braking and the ramp centering hole sheering which allowed the adjuster to loosen and drop out. This unconstrained the shoe's enough to allow the wheel cylinders piston past its travel, pushing its seal out.
Bought a new wheel cylinder, spring kit(replaced all springs including broken one), and adjuster kit(replaced entire adjuster assembly including broken cable ramp). reassembled, bled the brakes and I was on my way, or so I thought.
Fast forward a month or two later. I'm driving down the freeway at about 65mph, moderate San Diego traffic, Kayak in the back. Traffic starts to slow so i get on the brakes and start slowing down, suddenly the pedal goes to the ground again. I downshift and shoot across 2 lanes of traffic to avoid hitting someone. stomp on the parking brake and skid to a halt with, I'm guessing, one wheel on an off ramp. I get out, go look at the drivers side rear wheel and sure enough, a puddle of brake fluid was forming under it.
After a $85 tow home (Chula Vista to La Jolla), I pull it apart and find a similar scenario. Adjuster fell out when I pulled the drum apart, wheel cylinder seal was blown out, and this time the lower spring simply came out of its hole, but wasn't broken. The golden colored cable ramp for the adjuster was still intact, but it had fallen out of its hole (for those not familiar, it is held in the hole in the shoe by the bends of the upper rear spring which hooks in the same hole) instead it had slid down the spring and taken all tension off the adjuster arm again.
I rebuilt the cylinder(was new and still in good condition) and put it all back together again.
Both times it has happened the adjuster was screwed all the way in, When i rebuilt the drum I know i tightened the adjuster after i put the drum back on so it is backing itself out after the adjuster arm disengages. I checked to make sure the adjuster's star gear was profiled in the right direction and it is (both on the original and the one i replaced it with). What I think is happening is primarily due to the adjuster cable's ramp coming out of its hole allowing the adjuster to spin freely. It then works itself backwards and drops free, giving enough play in the shoe's 'see saw' to allow the wheel cylinder to pull itself apart.
It is fixed and functioning again, and has been about a month since the last incident happened. I've been very ginger when driving the truck and routinely check adjuster tension and make sure the adjuster arm is making contact with the star wheel. But I'd rather not have to worry about it.
Has anyone come across this kind of failure on a drum assembly before? Any ideas on how to prevent it? I realize that the catastrophic failure is partly to blame on the 200,000 mile master cylinder which is allowing front brake pressure to escape through the rear circuit, giving me no brakes at all with a failure anywhere in the system (unless the ranger master cylinder does not treat front and rear circuits independently by design, in which case i blame ford). The MS is next on the list of things to be replaced.
Sorry for the long winded post, any help would be appreciated. My GF would like to drive the truck but I simply do not trust it given such a critical safety issue. I have actively started looking for a disk brake explorer 8.8 as I hate drum brakes anyway but don't want to drop too much money on a high mileage beater.... yet...
First time it happened I was helping someone move a few loads of stuff to their storage unit, just loaded up and was driving the 2 miles to the storage unit when I went to stop at a stop sign and the pedal went to the floor. Luckily it was a residential area so i wasn't going very fast, and I'm not a late braker so I had tome to react before rolling right into traffic. Downshifted, parking brake, and pulled over. Coasted it back to the house and took a look. Rear drivers side wheel had a puddle of brake fluid under it.
Took it apart and the adjuster dropped out as i pulled the drum off. I found the wheel cylinder's seal was blown and the lower spring (that pulls the shoe's together and puts tension on the adjuster was broken. I also found that the gold colored ramp that holds the cable that puts tension on the arm which engages the star adjuster had broken. The round indented part that centers the ramp in the hole in she brake shoe had partially sheered off and was no longer held in place, this removed all tension from the cable and allowed the star adjuster to spin freely. What I thought was a freak accident of both the adjuster tension spring braking and the ramp centering hole sheering which allowed the adjuster to loosen and drop out. This unconstrained the shoe's enough to allow the wheel cylinders piston past its travel, pushing its seal out.
Bought a new wheel cylinder, spring kit(replaced all springs including broken one), and adjuster kit(replaced entire adjuster assembly including broken cable ramp). reassembled, bled the brakes and I was on my way, or so I thought.
Fast forward a month or two later. I'm driving down the freeway at about 65mph, moderate San Diego traffic, Kayak in the back. Traffic starts to slow so i get on the brakes and start slowing down, suddenly the pedal goes to the ground again. I downshift and shoot across 2 lanes of traffic to avoid hitting someone. stomp on the parking brake and skid to a halt with, I'm guessing, one wheel on an off ramp. I get out, go look at the drivers side rear wheel and sure enough, a puddle of brake fluid was forming under it.
After a $85 tow home (Chula Vista to La Jolla), I pull it apart and find a similar scenario. Adjuster fell out when I pulled the drum apart, wheel cylinder seal was blown out, and this time the lower spring simply came out of its hole, but wasn't broken. The golden colored cable ramp for the adjuster was still intact, but it had fallen out of its hole (for those not familiar, it is held in the hole in the shoe by the bends of the upper rear spring which hooks in the same hole) instead it had slid down the spring and taken all tension off the adjuster arm again.
I rebuilt the cylinder(was new and still in good condition) and put it all back together again.
Both times it has happened the adjuster was screwed all the way in, When i rebuilt the drum I know i tightened the adjuster after i put the drum back on so it is backing itself out after the adjuster arm disengages. I checked to make sure the adjuster's star gear was profiled in the right direction and it is (both on the original and the one i replaced it with). What I think is happening is primarily due to the adjuster cable's ramp coming out of its hole allowing the adjuster to spin freely. It then works itself backwards and drops free, giving enough play in the shoe's 'see saw' to allow the wheel cylinder to pull itself apart.
It is fixed and functioning again, and has been about a month since the last incident happened. I've been very ginger when driving the truck and routinely check adjuster tension and make sure the adjuster arm is making contact with the star wheel. But I'd rather not have to worry about it.
Has anyone come across this kind of failure on a drum assembly before? Any ideas on how to prevent it? I realize that the catastrophic failure is partly to blame on the 200,000 mile master cylinder which is allowing front brake pressure to escape through the rear circuit, giving me no brakes at all with a failure anywhere in the system (unless the ranger master cylinder does not treat front and rear circuits independently by design, in which case i blame ford). The MS is next on the list of things to be replaced.
Sorry for the long winded post, any help would be appreciated. My GF would like to drive the truck but I simply do not trust it given such a critical safety issue. I have actively started looking for a disk brake explorer 8.8 as I hate drum brakes anyway but don't want to drop too much money on a high mileage beater.... yet...
