GMoney

My wife has been complaininig about the brake pedal feel in here '05 RX330 lately. She tells me that the RX's brakes are not responsive. At a red light I can actually press the brake pedal all the way down.

I take a look an notice the pads are worn. I ordered Toyota parts and get the rotors and pads replaced. Go for a quick test drive and the brakes feels the same.

My question is, can you press your brake pedal all the way down as if you were "flooring it"? It takes a little effort to do so. While applying the brake do you find yourself pressing the brake pedal lower than you would in another car?

xfirechief

Sounds like there may be air in the lines. Has the fluid ever been flushed out? If u DIY try to Get as much of that old fluid out as u can then bleed the system. Just may take care of the issue.

968racer

If not this then maybe the master cylinder. Try bleeding the brakes first.

GMoney

OK I will blead the lines. Any recommendations for fluid? Does Lexus offer different colored fluid so that I can bleed the old yellow and replace it with say...blue fluid to ensure it was flushed properly?

01LEXPL

iTrader: (10)

mushy pedal is oftentimes than not an issue with air in the lines.

salimshah

Even if you have old fluid in the reservoir + tubes, the brake pedal should not go to the floor. Even before touching the pads, I would look for leaks. If there is no leak, the Master cylinder is bad. The only exception would be if there some how air was introduced in the system [which by itself is not possible, assuming no one as monkeyed with the brakes]. If the air can get in by itself, you will see a leak too.

One you get into replacing the master cylinder, you will be purging the old fluid out.

Rule of thumb, your left toe should be able to slide underneath fully depressed brake pedal.

Salim

RXSF

...i can floor my pedal

xfirechief

Bleed It !

1st Step. Get all the old fluid out of the resevoir you can before starting. Then fill it with the new fluid & go to it. You should be able to tell when the new fluid is coming through as it will look lighter & clearer too.

Use any NEW synthetic fluid & basically flush all the old stuff out durning the bleeding process. Make sure u have enough new fluid on site.

GMoney

yes I agree, I will take your advice and bleed it first..cheapest troubleshooting method.

There are no leaks as the fluid level is still level.

DOT3 synthetic..I do have some ATE DOT4 in the house can I use that?

xfirechief

DOT 3 & 4 is compatable per the website I just looked at. Amsoil.com
Dot 4 has a higher temp rating then the DOT 3.

salimshah

If you want to go that that way buy a larger bottle of brake-fluid.
My way would be trouble-shoot logically first instead of cheapest first .. but that is just me.

DOT4 is more stringent and it should be fine. If the brake fluid bottle has been sitting on shelf with lot of air volume between the fluid level and cap, you may think about getting a fresh bottle.

Salim

Boognish

You do know that you should use fluid which has never been opened before, right? Brake fluid absorbs water, so using fluid from a container that's previously been opened is a no-no.

xfirechief

If the top is on tight I don't think there would be a big problem at all.