500% improvement in Braking
10-26-2004, 09:46 PM
#21
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Originally Posted by Bumpin' Yota
dont forget that if you have lifted the truck and not adjusted the brake booster valve your rear brakes wont engage as well as if it was adjusted.
The brake booster valve on the rear axle actually senses how much load you are carrying based on its tilt and boosts more power to the brakes accordingly.
In my case I lifted the rear end about 2.5" or so, then tossed ~600lbs of car audio gear in it. So not only was it sensing a light load from my net 2" lift but I also had extra load that wasn't sensed.
I adjusted the booster valved and BOOM I can almost stop on a dime now.
BE WARNED: you do NOT want the rear axle braking more than the front....so do this at your own risk and test it out on an open wet parking lot. Again perform at your own risk.
The brake booster valve on the rear axle actually senses how much load you are carrying based on its tilt and boosts more power to the brakes accordingly.
In my case I lifted the rear end about 2.5" or so, then tossed ~600lbs of car audio gear in it. So not only was it sensing a light load from my net 2" lift but I also had extra load that wasn't sensed.
I adjusted the booster valved and BOOM I can almost stop on a dime now.
BE WARNED: you do NOT want the rear axle braking more than the front....so do this at your own risk and test it out on an open wet parking lot. Again perform at your own risk.
3rd Gen's with ABS don't have the LSPV, but non ABS trucks have this
10-27-2004, 05:42 AM
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You adjust the rears by putting the truck in REVERSE, then going about 3-4 MPH in REVERSE, you pull up and release the E-Brake rapidly...
Having overhauled and repaired Toy rear drums many times, it doesn't look to me like "reverse" (or moving at all) has anything to do with it either. All you should need to do is pull the e-brake lever. Simply using your e-brake on a regular basis should keep the brakes properly adjusted. If not, then there is something wrong that needs to be fixed. Sometimes the bell crank pivots get gummed up or rusty and hang up, etc.
10-27-2004, 05:59 AM
#23
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i had sim prob with my 90 i went to 5 mechanics same old thing seemed my fronts were working harder till i met the mechanic he told me take it in to his shop , well dont know what the part is called on my 90 on the rear axle theres like a bleeder tube , he told me he did a test and it was at 500 lbs inthe rear where my front is at 1200 big difference so he adjusted the pressure to 800lbs now i can stop on a dime with no prob no spongy feeling i was having for over a year funny thing one of the five was at a dealership and they didnt know the prob, guess its good to know a good honest mechanic
10-27-2004, 06:16 AM
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I've always just jacked the rear axle up, put my truck in neutral, and adjusted the rears by hand. I probably do this every other oil change, or 10K miles. I've never heard of backing up and pumping the e-brake, but I"ll give it a shot next time. I don't necessarily agree that just using the e-brake without any backwards movement will work at all. I use my e-brake all the time and the thing only gets weaker as the miles rack up in between adjustments. I think the plus to jacking the rear axle up and adjusting the rear brakes is that you can dial in the rears a little more. When properly adjusted, you should have to work to spin the rear tires. My buddy is a ASE master mechanic for toyota and showed me that I was always adjusting the rears to little, as he could spin the rear tires easily. With the proper adjustment, the rear tires should be hard to spin be hand, and I usually only can get 3-4 clicks on my e-brake with a moderate pull.
10-27-2004, 06:38 AM
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Originally Posted by ErikB
I don't agree with needing to be going in reverse (or moving at all). I've heard that mentioned by some over and over, but have never read it in any Toyota documentation.
I wouldn't say my braking is much better, but the pedal is firm up top.
10-27-2004, 07:00 AM
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Originally Posted by zebra1550
I've always just jacked the rear axle up, put my truck in neutral, and adjusted the rears by hand. I probably do this every other oil change, or 10K miles. I've never heard of backing up and pumping the e-brake, but I"ll give it a shot next time. I don't necessarily agree that just using the e-brake without any backwards movement will work at all. I use my e-brake all the time and the thing only gets weaker as the miles rack up in between adjustments. I think the plus to jacking the rear axle up and adjusting the rear brakes is that you can dial in the rears a little more. When properly adjusted, you should have to work to spin the rear tires. My buddy is a ASE master mechanic for toyota and showed me that I was always adjusting the rears to little, as he could spin the rear tires easily. With the proper adjustment, the rear tires should be hard to spin be hand, and I usually only can get 3-4 clicks on my e-brake with a moderate pull.
Are your wheels/drums hot after driving like this? Especially just after re-doing your adjustment?
10-27-2004, 08:14 AM
#27
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I found this interesting:
http://auto.howstuffworks.com/drum-brake2.htm
http://auto.howstuffworks.com/drum-brake2.htm
In Figure 7, you can see that as the pad wears down, more space will form between the shoe and the drum. Each time the car stops while in reverse, the shoe is pulled tight against the drum. When the gap gets big enough, the adjusting lever rocks enough to advance the adjuster gear by one tooth. The adjuster has threads on it, like a bolt, so that it unscrews a little bit when it turns, lengthening to fill in the gap. When the brake shoes wear a little more, the adjuster can advance again, so it always keeps the shoes close to the drum.
I didn't know why, but I knew it worked, that's why I shared it. I thought it was more common knowledge, but obviously it wasn't.
10-27-2004, 08:41 AM
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The only reason it may help is that it will rotate the shoes in the opposite direction from normal and introduce a bit more play allowing the adjuster to do more. That can't be bad at all. I'll try it too. GM brakes work in a different method. With those, driving in reverse and applying the brakes adjusts them and the handbrake does nothing. I think that's where the misnomer comes from.
Toyota drums (esp in the 3rd Gen) are really troublesome. I'm glad they went to disc in the 4th. I still have to say, make sure the adjuster lever in the drum can return fully.
Toyota drums (esp in the 3rd Gen) are really troublesome. I'm glad they went to disc in the 4th. I still have to say, make sure the adjuster lever in the drum can return fully.
Last edited by LarsDennert; 10-27-2004 at 08:42 AM.
10-27-2004, 09:55 AM
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It helps if you read the whole article... 
Our brakes are of the latter mentioned design.
In Figure 7, you can see that as the pad wears down, more space will form between the shoe and the drum. Each time the car stops while in reverse, the shoe is pulled tight against the drum. When the gap gets big enough, the adjusting lever rocks enough to advance the adjuster gear by one tooth. The adjuster has threads on it, like a bolt, so that it unscrews a little bit when it turns, lengthening to fill in the gap. When the brake shoes wear a little more, the adjuster can advance again, so it always keeps the shoes close to the drum.
Some cars have an adjuster that is actuated when the emergency brake is applied. This type of adjuster can come out of adjustment if the emergency brake is not used for long periods of time. So if you have this type of adjuster, you should apply your emergency brake at least once a week.
Some cars have an adjuster that is actuated when the emergency brake is applied. This type of adjuster can come out of adjustment if the emergency brake is not used for long periods of time. So if you have this type of adjuster, you should apply your emergency brake at least once a week.
10-27-2004, 11:00 AM
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Andy
Do you think it will work on the 4th Gen as well? It has a disc drum combo in the back. Disc for normal braking and a little drum just or the e brake. My e brake is pretty lame at the moment. Obviously normal braking is just fine.
Do you think it will work on the 4th Gen as well? It has a disc drum combo in the back. Disc for normal braking and a little drum just or the e brake. My e brake is pretty lame at the moment. Obviously normal braking is just fine.
10-27-2004, 01:13 PM
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I'm not much of a mechanic, but is it possible to convert the rear brakes on a 3rd gen to discs? If it is possible, how involved is it, like a 3 or 4 day ordeal?
10-27-2004, 01:24 PM
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What would be nice is too adapt the 4th Gen discs but that is really tough. The housing flanges are different. Some people use modifed GM front rotors and Eldorado calipers (but they are junk). I've schemed on using Ford calipers which have a handbrake bracket. There are many calipers out there with the ebrake setup. Even my wife's Altima has them but they are way to small. For the time I'll suffer with the drums. They vibrate on and off. Usually when they are a bit cold but some times when they are hot. Could be out of round delaminating tires too.
10-27-2004, 04:19 PM
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Originally Posted by Haniblectre
I'm not much of a mechanic, but is it possible to convert the rear brakes on a 3rd gen to discs? If it is possible, how involved is it, like a 3 or 4 day ordeal?
They make a rear disc kit for the Tundra, not sure if they use the same axel flange or not though.
10-27-2004, 04:53 PM
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Originally Posted by George4door
What about a swap from a sequoia.
They make a rear disc kit for the Tundra, not sure if they use the same axel flange or not though.
They make a rear disc kit for the Tundra, not sure if they use the same axel flange or not though.
The sequoia uses a different axle flange, so it would be very difficult, and you would have to do a lot of fabrication to make it work.
10-27-2004, 06:13 PM
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I don't even drive mine in reverse to adjust them. I can just sit in the garage with the engine off and pump the handle. I can feel and slightly hear the clicks as the adjuster snaps over the adjuster wheel in the brake drum. then I use the slight grade on my driveway to test that it holds it at 5-7 clicks.
10-27-2004, 06:17 PM
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Originally Posted by ErikB
So you'd rather have dragging brakes than a little extra pedal/lever travel?
Are your wheels/drums hot after driving like this? Especially just after re-doing your adjustment?
Are your wheels/drums hot after driving like this? Especially just after re-doing your adjustment?
10-27-2004, 11:18 PM
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Originally Posted by NorCalVP
The sequoia uses a different axle flange, so it would be very difficult, and you would have to do a lot of fabrication to make it work.
