What can I do about soft brakes on my car?

April 22, 2014 5:29 PM

I have a newly acquired 2007 Lexus ES350 sedan. It was my dad's, it is in excellent shape, has been well maintained, and has 50,000 miles on it. I drove a 2003 Lexus before this and had a similar issue to the one I'm having on the 2007, which is that the brakes are just too soft for my tastes. It seems it is part of Lexus' "feel" to keep the ride smooth but I really dislike that I have to press so far and so early to get a good stop.

So, what are my options to improve the responsiveness and "tension?" A quick google mentioned braided stainless steel brakes. Is that what I want here? Any ideas on how much changing the brakes more to my liking will cost?

Thanks!

posted by rbf1138 to Travel & Transportation (5 answers total)

I don't know specifically about the brakes on a Lexus, but it is also a matter of the size and configuration of the master cylinder, the brake booster and the calipers. In general braded steel brake lines will firm up a brake system a little but it generally has the property of making the brake 'feel' more linear and from a little a pressure=a little braking to a lot of pressure=a lot of braking. They also handle high heat a lot better then rubber lines.

This is why they are preferred for racing-they make the car more predictable, not that the help with the actual braking effort at all.

Before I embarked on replacing the soft part of the lines, I would get the brake fluid replaced with new high quality fluid (whatever propriety fluid Toyota recommends) and put on high quality NON lifetime brake pads all the way around. The factory Toyota set would be best (and probably not cheap) with all the shims installed. Lifetime warranty pads are usually really, really hard and don't generate enough friction and seem to be really rough on rotors. With only 50k on the car it is entirely possible that it is still on its original pads and they are just worn down enough to give a mushy pedal feel or aftermarket cheap pads were put on that aren't very good. And over time the fluid gets water and sometimes air in the lines and this can also lead to the feeling you are describing. Don't neglect to change whatever this car uses for parking brakes either (a lot of cars with 4 wheel disc brakes have a little miniature drum brake in the rear hub that also wears out).
posted by bartonlong at 6:04 PM on April 22, 2014

First stop is to flush the brake fluid and bleed the brakes properly (by a shop that can bleed the ABS unit effectively). Then new pads of good quality (not the cheapest ones) and then see what the issue really is.

Old brakes and old brake fluid can really affect pedal feel. This needs to be eliminated before any other work is undertaken.

A quick google mentioned braided stainless steel brakes.

If you have a 'long' brake pedal rather than a slightly spongy feel, this will do nothing to help you. If you press the brake pedal until it is firm (engine running, while stationary) and there is still a little bit of 'bounce' in the pedal at that point, then braided lines can help. The rubber between the hard lines on the car and the caliper have a little flex in them (especially when they are older) so they can make a difference to pedal feel, although they don't make much difference in the range from start of pedal travel to initial bite/50% braking force.
posted by Brockles at 6:32 PM on April 22, 2014 [5 favorites]

Nthing that your first move is to flush, refill with quality fluid, and have them properly bled. Don't worry about fancier solutions until you do that.
posted by werkzeuger at 10:31 PM on April 22, 2014

Agreeing with Brockles - a flush and and bleed should be your first step. Old dirty fluid can really affect pedal feel. Then look at new pads too.
posted by Big_B at 8:49 AM on April 23, 2014

You said the car has been well maintained. Therefore the brake fluid has been replaced at 30k, and is due again to be replaced at 60k. Doing it a little early, at 50k, couldn't hurt. Any air bubble in the ABS pump unit will soften brake feel, so that is what an effective bleed is about.
posted by artdrectr at 9:59 PM on April 23, 2014