draco

My foot brake is not as tight as it used to be. Is this an indicator of brakes needing the replaced? Also is there a procedure on how to adjust the foot brake? Is this procedure okay as a DIY or will it need specialist intervention?

RX330inFL

Are you talking about the travel in the brake pedal before the brakes begin to engage? Takes more travel, you have to push further, to get the brakes to grab? Just trying to decipher your question.

Front disc pads are not adjustable.

When you have a moment jump in your RX and set the parking brake. Release and set again and then release. How does the parking brake feel? Loose? Take a quick drive. How do the brakes feel? Probably will not make much of a difference though this information may be important.

Usually you will hear the wear indicators start to squeal when you are overdue for pads though the best way is for a visual inspection.

rcy

The pictures related to the two following sets of instructions are at the bottom of the post.

If you are talking about the parking brake, they are at the rear and they are the 'drum in disc' type, meaning inside the 'hat' of the rotor (which is a drum) there are brake shoes and assorted springs etc. that grip the inside of the hat when you apply the parking brake. These are easily adjustable in two places. I would start at the rear.

Remove the wheels - at the bottom of the caliper hat (6 o'clock position), you'll see a rubber plug. Remove this plug and shine a light inside so you get an idea of what you'll be doing....

Actually this will take too long to type out...I'm going to see if I can post a diagram with instructions..

The first picture is adjusting at the rear wheel. The second is inside where the brake pedal is. Usually, adjusting at the rear is enough. The inside adjustment is needed (I think) if the cable stretches over time.

Rear wheel instructions:

Remove the rear wheel.

Temporarily install the hub nuts. (you have to do this or the rotor will be loose)

Remove the shoe adjusting hole plug.

Turn the shoe adjuster and expand the shoe until the disc locks.

(For this, you just need a flat head screwdriver and you lever it against the star shaped adjuster.)


Turn and contract the shoe adjuster until the disc can rotate smoothly.


Standard:
Return 8 notches


Check that there is no brake drag against the shoe.

Install the shoe adjusting hole plug.

Remove the hub nuts.

Reinstall wheel - MAKE SURE YOU TORQUE YOUR LUG NUTS

Torque: (103 N*m{ 1,050 kgf*cm , 76 ft.*lbf }

__________________________________________



Cabin brake pedal adjustment:


Fully depress the parking brake pedal and release it to engage the parking brake.

Depress the pedal to the floor again, and release it to disengage the parking brake.


Slowly depress the parking brake pedal to the floor, and count the number of clicks.

Standard:
5 to 7 notches at 300 N (31 kgf, 68.3 lbf)

If you are outside of this range, AFTER adjusting at the rear wheels, then follow the rest of these instructions:



5. ADJUST PARKING BRAKE PEDAL TRAVEL


Depress the parking brake pedal. Hold the wire adjusting No.1 nut using a wrench and loosen the lock nut.


Release the parking brake pedal.


Turn the wire adjusting No.1 nut until the parking brake pedal travel meets the standard.


Hold the wire adjusting No.1 nut using a wrench or equivalent tool and tighten the lock nut.



Torque:
6.0 N*m{ 61 kgf*cm , 53 in.*lbf }


Count the number of clicks after depressing and releasing the parking brake pedal 3 or 4 times.


Check whether the parking brake drags.


When operating the parking brake pedal, check that the parking brake indicator light comes on.

rcy

Here's a better diagram of where the inside adjuster is..where it shows 'lock nut' and 'wire adjusting nut' is what you're looking for. Like I said, though, usually, adjusting at the rear wheel is enough.

salimshah

Hydraulic brakes (front and back) ... regular brake ... is self adjusting ... as the brake pads wear down the reservoir level drops .. you need to keep the reservoir at full mark. Checking procedure is when you apply the brake the pedal should stop at a point and you should be able to slide the other toe in and out of the gap between the pedal and the floor. If the pedal sinks or feels mushy then have them examined for leaks or malfunction in the master-cylinder.

Auxiliary/Parking brake: [Thank you rcy for your post] Drum mechanism and it is once again self adjusting, Under normal conditions the parking brake would compensate for the pad wear. You can help the self adjustment by operating and releasing the brake couple of times. Once the pad wear goes to max or when new shoes are installed then you need to adjust the start net [or even when you want to remove the rotor]. Before that time, one needs to examine the cable, which is in three sections. Pedal to "Y" split and then to each of the rear wheel. Look for frays or abnormalities. The set-up is pretty basic .. similar to brakes on a bicycle ,, steel cable in sheath. I would advice against touching the star nut [unless you know what you are doing]. You can over adjust and cause a drag -> heating -> more drag -> wheel seizure. If you know what you are doing go ahead. I touch the star to get the drum off and then adjust it low so that I can slide the drum on .. center the pads ... slide the drum off and move the star nut ... repeat and on the final assembly the drum still goes on easy [star adjustment is still low] and then let the auto-adjust take over to do the rest of the adjustment on it own. [The auto adjustment mechanism moves the star nut one click at a time on its own]. IN my view all adjustments are for initial set up, once that is done then no more adjustments are needed. If suddenly some thing happened, you need to investigate and and find/fix. Tweaking the adjustments will only mask the problem.

Salim

rcy

I agree you shouldn't be messing with your brakes unless you know what you're doing.

Yes, you do have to be somewhat mechanically inclined, however, ff you just follow these two steps (which are direct from the service manual, by the way)......

Turn the shoe adjuster and expand the shoe until the disc locks.


Turn and contract the shoe adjuster until the disc can rotate smoothly.

....then there's not much chance of overadjusting and causing drag. Once you back off the star nut so that you can rotate the rotor freely (i.e. no drag), then I don't see how drag can be reintroduced into the system.

draco

I think it would be fair to say that I can replace the brake pads on the car, but given that the foot brake is quite involved (and I do not know what I am doing there), it might be best for me to take the car into a shop and have them do the brakes and relative adjustment. Thanks for the info all.

salimshah

draco ... are we talking about parking brake?

Salim

draco

Probably should clarify that a bit, but yes the foot-operated parking brake (not the normal brake pedal).

jfelbab

If your brake fluid is low be sure to use the correct fluid as Lexus just needed to perform a recall on some vehicles that may have caused wrapping of the master cylinder seals by using the wrong fluids.

You didn't mention how many miles were on your set of brake pads and whether you measured the pad thickness. No sense messing with adjustments if the pads need replacement. When the pads get down to 2 mm its time to replace them.

If you are not mechanically inclined have Lexus measure your pads at your next oil change. They will do that for free at my dealership.

salimshah

Good, rcy is on the right track.

Few words of caution:
One needs to investigate, why the auto-adjustment is not working? The way the auto-adjust works is that you repeatedly apply [max travel] the brake and release it. The pawl recognizes the travel is long and it kicks the start nut one cog at a time.

One more thing, if you have not worked on drum-shoe brake, the apparatus is bit complicated and held in place by springs and retainers.

Salim.