Rx400h parking brake adjustment

[welland]

I've been looking for a guide about how to adjust the parking brake on an rx400h, but can't find one.   Can anybody possibly point me in the right direction please?

Mine has just failed the mot with inefficient parking brake on both wheels, so it needs sorting out. There is a lot of travel on the pedal and the bite is too low.  

I figured that there is probably an adjuster on each wheel, but possibly a central adjuster as well.  Any advise about where to find them and how to do it would be gratefully received.  

[kenhall]

Basic method is to adjust first at each rear drum with “foot/ hand” brake fully released. The adjustment starred wheel inside the drum is accessed after removing the small rubber bung at the six o’clock position.  The starred wheel is then turned one way or another with a flat blade screwdriver poked through the hole to bring the shoes in full contact with the drum and then backed off slightly to prevent binding. It is a bit of a pain to do I have found. From memory moving the starred wheel upwards brings the shoes into contact with the drum and vice versa.

Replace the rubber bungs and then adjust the pedal travel to about 7 clicks (fully on) by adjusting the primary cable lock nuts behind the pedal (grovelling in the driver’s footwell required for access!!)

Edited November 25, 2021 by kenhall
Additional info

[welland]

Thanks a lot Ken.  How is the starred wheel accessed? I presume that the rubber bungs are at the back of the hub? Can they be accessed from under the car without removing the wheels?

[Mihanicos]

If the hubs are not true then the hand/foot brake will not be able to hold the car even on a small gradient. Adjust as outlined by another learned member and  if unsuccessful, take the hubs off and have them machined. 

Chris.

[kenhall]

Hi Peter,

The rear wheels have to be removed and you will find the small (10mm?) rubber bung between the wheel studs.

If you are prepared to remove the drums / discs temporarily (brake calipers have to be moved out of the way) you will get a better picture of the work required. Also you can check if the star wheel adjuster is free to turn and lubricate it’s threads if necessary. The remaining brake shoe lining thickness can also be checked although they wear very slowly.

I will try and post some explanatory pictures later.

Edited November 26, 2021 by kenhall
Proof read

[Delphius1]

Basically chock the front wheels wheels so the car can't roll, release the parking brake and then back off the adjuster on the pedal (not a lot of space, so expect to spend a bit of time doing it and a chiropractor after contorting to get under the dash. You may have to partially engage the pedal to get a decent angle on the adjuster nut. But once it's backed off, release the pedal.

You'll need to jack up the back of the car so the wheels move so you can check when the handbrake locks the wheels. Use axle stands for safety. You may need to put the car in neutral using the shift lock release so the wheels turn, which is why the front wheels need to be securely chocked so the car can't roll forwards or backwards because there will be nothing else to stop it.

Once that's done, you can move to the back of the rear brake and pull the bungs out for the star adjuster. Move the star adjuster until the parking brake locks the wheel. Then back off until the wheel moves. From experience it can be anywhere between 5-8 turns. 

Repeat for the other side. 

Try the parking brake in the car. If the pedal moves too much then repeat the adjustment at the back of the drum but with fewer turns to back it off until you're happy.

It may take a few goes to get the sweet sport where the pedal applies the parking brake when the pedal is depressed, but the wheel turns freely when the parking brake is released. Once done, replace the bungs in the back of the drum.

If the disc brakes are binding and interfering with setting the parking brake, undoing one slider pin and flipping the caliper up out of the way so it's off the pads should allow you to turn the wheel freely.

I forgot to mention if you flip the caliper out of the way you'll need to remove the wheels to accomplish that. If the wheels are removed, you'll need to use the wheel nuts to secure the disc rotor in place while you adjust the parking brake.

 

 

 

[kenhall]

The official method:

24001100.pdf