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The brakes are a little underwhelming in my opinion on my 98 LS400. By that, I mean that the pedal feel is sort of squishy. There isn't much "bite" to the brakes, and to really stop, I notice that I have to really push down on the brakes. To give you some perspective, I have experience driving a 06 Camry, a 99 Sienna, and a 18 RAV4.
I first tried bleeding the brakes. I used probably 2 liters of brake fluid, so I feel that I did a pretty good flush of the system. Nothing changed after bleeding the brakes. Everything felt exactly the same. I might as well have saved myself the effort.
The Camry's brakes are relatively responsive. There's definitely more bite here than on the LS. Perhaps it's just because it's a lightweight car. The RAV4's brakes are also okay. The Sienna is a little underwhelming, but I think that's just because it hasn't had new pads or rotors since the last millennium.
Would new pads help with the "bite"? Or are all LS400s just like this?
Mine the pedal is rather firm and the hardest part is modulating stopping smoothly because so little pressure is required.And they really pull the car to a stop quickly.They should stop with authority and no nonsense.The weakest oldster on the planet should be able to stop this car without issues.
Lots of good threads on brakes here.There is something about bleeding the brakes that is different on these cars Ive read here.Ive never done LS400 brakes myself.
I would turn the rotors and get new shoes,or if not that then replacing rotors with new,and new shoes.OEM rotors are better than aftermarket its claimed here.
No matter what,doing that is going to be good even if it isnt the issue in the end,but that should be the fix.Never hurts to do brakes.
Try a different pad compound. The Toyota ceramics work really well but they are not an aggressive type like some others are. They are quite effective though I have no comparison in relative stopping distances to others setups.
The brakes are a little underwhelming in my opinion on my 98 LS400. By that, I mean that the pedal feel is sort of squishy. There isn't much "bite" to the brakes, and to really stop, I notice that I have to really push down on the brakes. To give you some perspective, I have experience driving a 06 Camry, a 99 Sienna, and a 18 RAV4.
I first tried bleeding the brakes. I used probably 2 liters of brake fluid, so I feel that I did a pretty good flush of the system. Nothing changed after bleeding the brakes. Everything felt exactly the same. I might as well have saved myself the effort.
The Camry's brakes are relatively responsive. There's definitely more bite here than on the LS. Perhaps it's just because it's a lightweight car. The RAV4's brakes are also okay. The Sienna is a little underwhelming, but I think that's just because it hasn't had new pads or rotors since the last millennium.
Would new pads help with the "bite"? Or are all LS400s just like this?
Sounds like you have some trapped air in the brake actuator.
The instruction below might help you to remove it.
I had my brake fluid flushed when I bought my car (and every other fluid), so I presume my pedal feel is "how it should be". I have about 40% life left on my pads. I've driven about 30 or 40 different cars in my life and I would say the brakes are "normal" and don't have air\water or whatever in the lines.
There is a tiny little bit a deadzone at the top 1\4 inch of pedal travel. It does apply braking force, but very lightly. Then as you push more, the bite happens, and it progresses linearly.
Many other cars chose to go for the super tight brake pedal where that top 1\4 inch bites really hard.
A lot of this is calibration by the OEM, and choice of brake pads, brake booster, etc, etc. But I would say the 400 "bites" softer than most and require you to press deeper into the pedal to stop normally than most cars I've driven.
New pads would definitely help with pedal feel and brake pedal travel. Think about it this way, if you have 50k miles on your pads, the factory pads are probably at least half gone, meaning you'll have about 5-6mm of material less on EACH pad. So if your front pads (4 total) are worn down that much, then you'll have to push the pedal enough to cover the 20mm of pad material that's now missing from compared to when they were new. Also have to factor in rotor wear as well which could be another few mm of wear. Now also think about your rear brakes, and you can see where I'm going.
I work for Federal Mogul Motorparts, making all the pads for OEMs and pedal feel makes a huge difference in driver perception of how good a braking system feels.
Rockauto has some Wagner Thermoquiets ($15 or 21 per front set), which is our aftermarket material that is a really good compound. Its very low dusting and a "ceramic" material. I have that on the front and rear of my 99' LS and the fronts have over 60k miles on them and are about half worn, very gentle on rotors.
Another big difference is to check for corrosion on your rotors. Even though I have about half my pad life left, my rotors were pretty corroded with rust and the inner braking surface of the rotor was only being utilized about 80% due to this. I went to Oreilly Auto and had them turn both of them for $12 each this past weekend and it made a big difference. I'm still going to order a new set of pads, because my pedal travel is a bit too much as my pads have worn.
Since I have access to a Bridgeport mill at work, I took off about .5mm of friction from the pads to have a fresh layer to burnish onto the freshly turned rotors.
New pads would definitely help with pedal feel and brake pedal travel. Think about it this way, if you have 50k miles on your pads, the factory pads are probably at least half gone, meaning you'll have about 5-6mm of material less on EACH pad. So if your front pads (4 total) are worn down that much, then you'll have to push the pedal enough to cover the 20mm of pad material that's now missing from compared to when they were new. Also have to factor in rotor wear as well which could be another few mm of wear. Now also think about your rear brakes, and you can see where I'm going.
Disc breaks automatically adjust the clearances as the brake pads wear down.
You say you work for a OEM brake company though... is this information wrong? I would have thought automatic adjustment had been solved because if it weren't there, worn down pads would have a HUGE deadspot at the top of the pedal.
But generally yes, doing a brake job should improve the feel and stopping power with new parts and fluids.
You say you work for a OEM brake company though... is this information wrong? I would have thought automatic adjustment had been solved because if it weren't there, worn down pads would have a HUGE deadspot at the top of the pedal.
But generally yes, doing a brake job should improve the feel and stopping power with new parts and fluids.
I work at a supplier for the OEMs, we make the pads not the calipers or the system components. The piston seals only roll back to reduce drag when you let off the brake, they don't take up the missing pad material. As your pads wear, the pistons do extend outward, but instead of pad material being displaced, the fluid is displaced in the master cylinder and rubber brake hoses.
Compressing a pad against a rotor with more material will still feel better than compressing a worn out brake pad against the rotor, as the rubber lines will flex a bit more when more fluid is being displaced in the system.
Great pics Losiracer....you are on a roll of helpful posts,appreciate the time you spend and share with us.
Also some cars do have a mechanical adjuster in rear discs,My 2001 jetta had that.After pads removed you use a special tool set,I got the cheepy from harbor freight,and you screw the piston back down into the caliper.
So if your front pads (4 total) are worn down that much, then you'll have to push the pedal enough to cover the 20mm of pad material that's now missing from compared to when they were new
I'm not buying it. Even on cars with spring clips to reduce pad drag, the gap at the pad/rotor interface is about the width of a gnat's eyeball regardless of the pad thickness. I've never seen self-retracting caliper pistons which is what you'd need in order for the front brakes to operate in the manner you describe. If the pistons were to retract to their original position after a braking event, the master cylinder simply couldn't deliver enough fluid volume in a single stroke to re-engage those pads. For worn pads it would probably take 4-5 full pedal strokes to get those pads back out to the rotor surface. Ask the mechanic at my dealership who backed a Ford 3/4 ton into a wall when someone did a brake job without "pumping" the brakes back up after manually retracting the caliper pistons.
If anything, worn pads could feel better if the pad compound is compressible as there's less material to squish down (some formulations can compress enough to affect pedal feel).
As for maintaining a solid pedal feel, assuming there's no air trapped in the master cylinder, the lines, or the actuator, the only thing left is to loosen the reservoir cap and open one caliper bleeder screw at a time to let out the tiny air bubble that slowly forms due to imperfect piston seals. For me, gravity has done the trick every time.
You don't need to flush the system. Unless, of course, the fluid is old and it's time for fresh.
You don't need a special service tool to activate the ABS servo. Unless you're flushing the fluid and want to get every drop of the old stuff out.
You don't need a vacuum bleeder.
You don't need a pressure bleeder.
You don't need to machine the rotors. Unless their runout or TV is so severe that it's causing piston knockback. In which case I'd toss them and start new.
People overcomplicate and overspend on what is a remarkably simple and resilient system.
06-28-18, 01:04 AM
how are the brakes supposed to feel?
