drum issue, 2002 toyota tundra

[mikeinaustin]

today i decided to inspect and clean the drums. the drums have never been serviced before, truck has 60K miles.

the driver side drum looked brand new with almost no brake dust anywhere. the inside of the drum was very smooth and clean. the shoe pads were approx 6mm, uniform. i put cleaner on anyway, but all throughout i thought i had just wasted my time attempting to clean such "brand new" drums/pads. then i went to work on the passenger side drum.......

passenger side drum was totally black and caked with brake dust (about 1/2 inch high). the pad closest to the rear of the truck was uniform and about 5mm. the pad closest to the front of the truck was not uniform. at the top it was about 5mm but about 3mm by the time you got to the bottom. the inside of the drum itself had some deep and wide groves.

so either the driver side brake isn't doing anything putting all the load on the passenger side or something bad has happened to the passenger side. i have used the parking brake on a regular basis in an attempt to adjust the rear brakes.

please give feedback on what caused the above and what i should do to figure out why the passenger side is doing all the work.

 

[01rangerxl]

Maybe one of the self adjusters is sticking? Removing the adjusters and applying some grease to the threads may help.

 

[alanu]

Drums have brake shoes.

Make sure your wheel cylinder is not weeping fluid on the passengers side.

Make sure your parking brake cable isn't sticking on the passengers side.

 

[mikeinaustin]

no brake fluid anywhere. i pulled on the passenger side cable, and it seemed to move normally. i have not removed the adjusters and re-greased however. i did go and got myself some crc brake and caliper grease just in case i needed it though.

 

[alanu]

look behind the rubber boot on the wheel cylinder. Black and caked dust gets moisture from somewhere. Do you smell any gear oil from the diff?? suspected axle seal issues???

 

[mikeinaustin]

i don't smell or see any sign of gear oil on either wheel. the side that looks perfectly clean with no wear did have a axle seal leak about 55K miles ago that was fixed by the dealer.

 

[INDYMAC]

This service is normally provided at 15K or 30K scheduled maintenance. I would consult your mechanic to ask why it was never done.

 

[mikeinaustin]

took it apart again tonight...had wife push on brakes so i could see the action of both drum(really shoes). side with lots of wear acted normally (both shoes got pushed outward when she pressed brake and retracted when brake released).

on the side with no wear, only one shoe was moved when she pressed the brake, the other shoe did nothing. i know its not physically seized as i can move it with my hand just fine. do i got a bad wheel cylinder?

she also used the emergency brake so i could verify what each brake did (they acted the same). however, i believe that over adjust the brakes cause now i can't get the drums back on. i will have to back off the adjustment i suppose.

 

[Market525]

Mike,
Get your dealer to check to see if there are any TSB's out for this issue. I have a 2000 Tundra - which was the first year - and there WERE issues w/ the adjusters. I thought, but could be wrong, this was corrected after the 2000 model year. If by some chance you are a paid member of Tundra Solutions www.tundrasolutions.com -- then you could check for the TSB yourself. Seems to me the issue was number of teeth on the star wheel - can't remember specifics, though. Good luck, Steve

 

[Junior]

The RH sounds to be normal wear. The LH isn't doing much braking. Due to the wedging nature of drum brakes, the shoe to the front usually does more of the braking than the rear. Also it is normal for the shoe to wear a little uneven for the same reason.

 

[mikeinaustin]

but i am correct in believing that when you push on the brake(even though the back is up on jackstands) that the wheel cylinder should push in both directions evenly, isn't this true???

 

[Junior]

The wheel cylinders I am familiar with are open in the center. (open cylinder with a piston on each end that pushes on the shoe actuation pins) Push one in and the other will extend. Depending on the return spring bias and drag on the shoe, in the free state one could move without the other. Try holding the one that moves in while someone presses the brake pedal. The other shoe should move.

But like I said, this is how the ones I have repaired worked.

 

[mikeinaustin]

without brake applied, i can push on one end and the other end will come out (and vice-versa). my concern is when the brake is applied under hydraulic pressure, only one end comes out, the other end apparently does nothing under that type of pressure and so that shoe will never touch the drum.

 

[Junior]

One shoe can't apply pressure to the drum without the opposite shoe applying equal and opposite pressure to the other side of the drum. What will happen when you apply the brake is the following:

1) shoe with the least resistance will move first until it touches the drum
2)after the first shoe makes initial contact the second shoe will move out and make contact with the drum.
3)both brake shoes will exert equal pressure on the drum.

Your functions sounds completely normal. One return spring is usually a little stronger in order to overcome the wedge effect of the shoe.

IMO, the adjuster on that side is not self-adjusting correctly and probably never did on that side. I have a vehicle where the adjuster arm is worn and it no longer turns the star gear on the adjuster. I, from time to time, open the dust cap and turn the adjuster manually with a screwdriver.

Another thing you can do is make a few moderate stops and then see if the LH is cooler than the RH. If it is cooler then it isn't doing equal braking.

Automotive drum brakes are cheap but can be a little moody at times.

 

[mikeinaustin]

yes the passenger side drum is hotter than the driver side drum (tested several time today). both are hot, just one is very hot.

i tested the adjuster with the drum off by manually pulling on the e-brake cable, everything functioned normally, parts look brand new and well greased. just in case, i did hand adjust with a screw driver till i could just get the drum on and then backed off a little.

 

[Junior]

I guess I am stumped.

If the little star wheel rachets then I don't know. Good luck.

 

[Matt_S]

I'm really surprised no one has suggested that you bleed the brakes. Everything sounds like it's working normally, but nothing written here has eliminated air in the lines as a potential problem. This could cause exactly what you're seeing.

 

[mikeinaustin]

yes i have replaced all the brake fluid in the entire system. i have no idea what could have caused this.

i do know this, the passenger side is still hotter than the driver side. so whatever has been going on for the last 60K miles is still going on.

since the driver side is hot, it is doing something, just not as much as the passenger side. i cannot explain why the passenger side was absolutely caked in brake dust while the driver side had pretty much none.

 

[Tosh]

Somewhere there will be a written procedure on exactly how to adjust the drums for this vehicle (factory service manual?). But I would first check on Toyota Tundra-specific websites for the same symptoms, and see what the consensus is there.

 

[George7941]

Perhaps you ended up with different shoes on both sides stemming from the dealer repair of the oil leak. The new shoes do not grab as much as the OE shoes.