The good, the bad and the confusion with my recently attempted brake job

[t1704]

Okay, so I have an '01 Tundra with many of the brake problems others have had. I was really trying to avoid the full big brake job, so I bought some Brembo rotors and Hawk pads hoping that with those, some adjusting of the rears and good driving habits, I wouldn't have to do the wole thing.

So there I am, truck on jack stands, air compressor fired up, beers on ice etc... I unpack the hawk pads and can't believe how small they are, definitely one of the reasons the brakes are junk. As I crawl down to start loosing the calipers bolts...BAM, I notice they're the 13we ones, great news I thought, someone has already upgraded the calipers. Then I thought, why the hell am I still having problems. So I can't do much as I now need to exchange the pads, but decided I would adjust the rears. I probably adjusted them 7 or 8 clicks on each side, definitely paying attention not to overtighten. After putting the wheels back on and driving, adjusting the rears made a very big difference, but there's still that pulsating in the front wheels. So I now have the right pads and will replace rotors and pads this weekend, but does anyone know why there were still problems with the larger calipers?? I'm assuming regardless, the rotors are warped, right? How concerned shoule I be at this point?

[Salty_Dog]

Originally Posted by t1704

Okay, so I have an '01 Tundra with many of the brake problems others have had. I was really trying to avoid the full big brake job, so I bought some Brembo rotors and Hawk pads hoping that with those, some adjusting of the rears and good driving habits, I wouldn't have to do the wole thing.

So there I am, truck on jack stands, air compressor fired up, beers on ice etc... I unpack the hawk pads and can't believe how small they are, definitely one of the reasons the brakes are junk. As I crawl down to start loosing the calipers bolts...BAM, I notice they're the 13we ones, great news I thought, someone has already upgraded the calipers. Then I thought, why the hell am I still having problems. So I can't do much as I now need to exchange the pads, but decided I would adjust the rears. I probably adjusted them 7 or 8 clicks on each side, definitely paying attention not to overtighten. After putting the wheels back on and driving, adjusting the rears made a very big difference, but there's still that pulsating in the front wheels. So I now have the right pads and will replace rotors and pads this weekend, but does anyone know why there were still problems with the larger calipers?? I'm assuming regardless, the rotors are warped, right? How concerned shoule I be at this point?

Does the pulsating only happen when you are braking? If yes, then the rotors are probably bad. If no, then it could be tire balance, alignment, steering rack bushings or tie rods.

[t1704]

Yes, just when braking.

[Salty_Dog]

Originally Posted by t1704

Yes, just when braking.

Sounds like warped rotors.

[MEvang]

You say you have the pulsation problem, but you've given no history. You didn't know the upgrade had been done so I will have to assume you bought the truck and then the pulsation developed?
What I'm getting at is you don't need to be real concerned if you don't know all the history. What is the rotor thickness now? These rotors could have been turned a few times. Is there any rust build up on the hub surface? Of course you don't know yet, but rust jacking can cause runout. When was the last time the rears where adjusted? The rears out can put extra strain on the fronts. What brand of pads are on these now? Some pad formulas can cause problems with the rotors that can lead to runout problems. What are your driving habits? Do you tow? Drive hard and brake hard? Then this can lead to pulsation problems depending on the pad formula. Last but not lest are the wheels always torque when installed? This is one of the leading causes of rotor problem.
So if you change the rotors clean the hubs good and torque the wheel you should be good to go. My only concern is your choice of pads.
Mike

[longwoodklon]

Originally Posted by MEvang

You say you have the pulsation problem, but you've given no history. You didn't know the upgrade had been done so I will have to assume you bought the truck and then the pulsation developed?
What I'm getting at is you don't need to be real concerned if you don't know all the history. What is the rotor thickness now? These rotors could have been turned a few times. Is there any rust build up on the hub surface? Of course you don't know yet, but rust jacking can cause runout. When was the last time the rears where adjusted? The rears out can put extra strain on the fronts. What brand of pads are on these now? Some pad formulas can cause problems with the rotors that can lead to runout problems. What are your driving habits? Do you tow? Drive hard and brake hard? Then this can lead to pulsation problems depending on the pad formula. Last but not lest are the wheels always torque when installed? This is one of the leading causes of rotor problem.
So if you change the rotors clean the hubs good and torque the wheel you should be good to go. My only concern is your choice of pads.
Mike

I've got Hawks on my pre-TSB Tundra. Been 2 years and no problems, just checked recently and plenty of pad left. I haven't figured exact mileage, but it's somewhere near 70k. I've been very happy with the Hawks.

That said, and I know we all think the brakes are the culprits, I think it's worth checking your steering rack. It's almost guaranteed that any older Tundra has bad bushings, replacing them does make a noticeable difference.
/Mike

[lelandstanford]

Don't forget to adjust LSV to max rear pressure.

[MEvang]

Yes, the load sensing valve should also be check if rapid front pad wear is a problem.
I know some people here have had good luck with Hawk pads but many have not. I think their pad break in proceeder is too aggressive and maybe they have changed this. But they are a racing pad manufacture and their formulas will be geared in this direction. Racing formulas are not always go for street use unless you tend to be a very aggressive braker, tow a lot or carry heavy loads most of the time.
I would not recommended these pads to anyone under normal circumstances, most people are much better off staying with the factory pads or a good name brand. This is my opinion based on 30 years experance in the brake and performanace car bussness.
Mike

[t1704]

Thanks everyone for the comments. To provide some background, I bought the truck used about 9 months ago. After driving it, I realized there were potential brake issues, although having done brakes on other cars in the past, I figured I'd negotiate a good deal, then replace pads and "potentially" rotors when I got the truck back home. That's when I began doing some research (Found this site) and became better acquainted with the magnitude of the brake issues on this particular truck. (I owned two tacomas prior to this) The guy I bought it from also said he paid about $700 a couple of months back to have the brakes done, but he didn't know what they (The local brake shop) did as he wasn't very mechanically inclined. According to CarFax, I'm the third owner, it still only has 53,000 miles and otherwise runs great.

So, after researching all of the problems, then considering how bad the pulsations were, I ASSumed that the TSB hadn't been done, shame on me. So, I bought the Brembo rotors and Hawk light duty, SUV pads and planned to adjust the rears while I was at it. Of course I had the wrong pads once I realized it had the larger rotors. My biggest question was, with the larger calipers, why still the problems. Without the history of prior owners, I guess it could be many things. When I first attempted this a couple of weeks ago, I did go ahead and adjust the rears and they were way out of adjustment. I think I adjusted them 8 clicks each side, and they could have used more, it did make a noticeable difference. I'm sure nobody will claim to have poor driving habits, but honestly, I don't brake heavily, I don't tow anything, there's no hitch on the truck, nor any signs of previous towing. I did torque the lugs to 83ft lbs when I put the wheels back on this last time.

The other thing to mention is the current pads, which look like OEM's have plenty of pad left and I can't feel any grooves in the rotor.

So, I plan to replace the rotors and pads this weekend, I'll adjust the rears again and hopefully that takes care of it. I'll be sure to clean any rust from the hub surface as well.

Regarding the LSPV, I'm hesitant adjusting this as I have no prior experience, any thoughts?

Thanks for the help and sorry for the long post.

Travis

[lelandstanford]

http://www.tundrasolutions.com/forum...inspection.pdf

[MEvang]

As you can see from the pdf Lelandstanford posted adjusting this valve requires a few special tools that most people don't have. I have a set of gauges, the main tool to do this but I will tell you I have never checked mine and here is why. After a good 10 mile drive to my job which is mostly down hill to the Maim River Valley the rear brake drum generate a good deal of heat as compared to the fronts. I checked this a while ago so I can't tell you the exact difference as I used a pyrometer. The thing is that the backs should be running cooler then the fronts but should be generating some heat. This is with an unloaded truck.
If the back seem to not produce much heat at all then they are likely not working. The other thing to consider is this, I need to adjust the rears about twice a year to keep a good pedal. Now this can vary a great deal depending on driving habit but the thing is, this stays consistent to the driving I do. If this were to change I would suspect a problem. Something to keep in mine.
The other thing to consider is too much pressure getting to the rears. If the rear drums get hotter then the fronts this would be a concern. You would likely notice along with this the back brakes locking up easily or if you have ABS, it activating very easily in wet conditions. I don't have ABS and run Bridgestone tires, the back do not lock up easily. The reason I throw tires in to the equation is that tire adhesion is a big factory to consider when your trying to determine brake lock up points. The first change I made to my brakes were better tires. The BFG that came on it were terrible in the rain, take off or stopping.
As far as you brake history goes this is basically what I figured, you just got the truck. I'm sure you read about all the possible causes, plus we can't yet rule out the rear brake drums. They are well known for causing brake shutter. I have found you can get a good indictor of drum problem while adjusting the rears. If the brakes get tight and then loosen as you spin the wheel you likely have warped drums.
As far as the fronts go, just make sure the hubs are clean. You might want to look at this:How To: Early Tundra Brake Upgrade
Even through this is about doing the upgrade I threw in some very good advice on installing pads and rotors.
Did Hawk send you a bed in procedure? Is so skip it, just drive normally and avoid any hard stops. Bed in procedures are for race cars.
Mike

[lelandstanford]

Sorry, the PDF file was for reference. I personally (then '02 Tundra) didn't not use the gauges at all.

Mine had slotted/cross drilled rotors and EBC Green pads. Rear were Porterfield carbon kevlar shoes with TRW drums.

The improved brake hardware basically means better braking power and less heat generated. Even decent braking (non-porous material) treading deep water.

The LSV were adjusted to the max. With Revo tires (245/75-16) and ABS, there's no problem with lock-up on dry pavement.

[MEvang]

I have to correct you on one thing. If you have better braking power you will generate more heat. This is what stopping is all about. Very basically you are taking the kinetic energy of the moving vehicle and using the brakes, turning it into heat. So brakes are basically heat generator the, bigger and better the brakes, the more heat it can generate.
After you turn that kinetic energy into heat the next thing is to get rid of it. Heat will be dispense through the rotor/drum, into the surrounding steel parts, hub bearing caliper/wheel cylinder, upright, and even the wheels and brake fluid. And then into the air. Physically smaller brake components don't dispense heat as well as larger heavier parts. This is one likely reason Toyota moved to larger calipers.
Now the problem with too big or too aggressive brakes, and yes you can make brakes too big. Brake can only perform up to a certain point and then the tires loose adhesion to the pavement.(Lock Up) The weight of the vehicle and the brand and size of the tires contact patch has everything to do with this.
For instance if the Revo you have, have a good grip to the pavement under most driving conditions you can get away with more rear brake pressure.
Problem is as a manufacture Toyota has to play it safe. GM took a big hit for trucks in the '80s that would easily lock up the rear brakes. Of course nobody talked about what tires where on these trucks when the began to have problems. (Likely old and bald) So you can see they must keep rear braking pressures on a pickup under stricked control, wet or dry pavement and loaded or unloaded. The LSV does a good job of this when correctly adjusted.
Mike

[lelandstanford]

Incorrect wording.

I meant better heat dissipation/resistance.

[MEvang]

Good discussion anyway.
Mike