Mico Brake Lock - Diesel Forum - TheDieselStop.com
Wheels, Tires, Brakes, and Suspension Discuss your wheels, tires, brakes & suspension topics here.
Sponsored by Discount Tire

LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 06-19-2011, 10:08 PM Thread Starter
Senior Member
Join Date: Mar 2011
Posts: 190
My Photos: (0)
Feedback Score: 0 reviews
Mico Brake Lock

I am thinking of installing a Mico electric brake lock (02-620-009) to supplement the factory parking brake. I have a 2000 F350 Super cab dually 4x4 six speed. I personally do not trust the oem parking brake. It will hold the truck....barely and with a trailer you may as well forget it. The Mico lock will hold residual pressure on the rear service brakes after the brake pedal is applied and the supplied switch is flipped. There is no effect on the service brakes when the switch is off. It is also supplied with a low pressure warning switch. I have used these on bigger trucks,wreckers and heavy machinery and they seem to work great. Looks like a simple install and should work. My only concern is will it have any effect on the ABS on the truck? I cant really see how it could but i am open to any opinions. BTW the parking brake shoes, backing plates, oil seals and hardware have been replaced. Thanks in advance.

2000 F350 DRW 7.3
tomlin is offline  
Sponsored Links
post #2 of 3 (permalink) Old 06-20-2011, 07:11 AM
Senior Member
FMTRVT's Avatar
Join Date: May 2001
Location: Jersey Shore (Not Seaside!)
Posts: 5,687
My Photos: (16)
Feedback Score: 0 reviews
We had used dozens of these on test vehicles over the years and as your own experience, they work very well. You will not have any ABS issues.

Now the warning. The reason for using DIH brakes rather then through the service caliper parking has to do with the type of friction material used in the service brake. Semi-metallic pads like all of the ones available for these trucks had a pretty good thermal expansion rate. The danger here is you park the vehicle, engage the hydraulic service brake, and as friction material and rotor cool they shrink back down and you loose hydraulic pressure and parking hold.

The question for the driver becomes how much pressure and how hot are my brakes. That is a problem even for those with brake thermocouples unless you know the friction material thermal swell characteristics.

Micro has taken steps to address this (after lawsuits from what I understand) that include a low pressure warning switch during the last decade or so. For me, it is essential that you hook this up to the horn or other warning circuit so if a problem occurs, you and anyone downstream will know there is an issue.

Now the probability of this happening is most likely rare, but running with a trailer has the highest potential for hot brakes, and the highest load placed on the parking brake activity.

You personally are probably aware of everything after the first sentence with your experience, but I thought I should put the rest in for anyone finding this in the future by using the search function.

On edit - for the parking brake to work well there are a couple of critical issues since the diameter of the DIH brake is so small compared to the vehicle the vehicles GVW. First the DIH lining has to be ground to a perfect radius,which is not necessarily the same as the drum. Next the rotor's DIH surface has to be grit blasted. You don't get this with aftermarket rotors, but if you know someone with a sand blaster you can improve your situation a little, but not up to OE standards. The last is running clearance, which for the DIH brake is tighter then a normal service brake. It should not be tightened to the point of dragging where the shoe lining wears out it ground radius advantage or wears off the grit blasted roughness.

The reason for the tightness gets you two advantages, both at the apply mechanism. The obvious is that it gains you more travel to apply higher pressure, and second all the application you can get at the center swing of pedal travel the higher the leverage. The farther off center-line the less mechanical advantage.

Former Vehicle Test Manager - Friction Products
03 F350SC 4x4 6.0 Auto 5/30/03

Truck Pictorials on Facebook. Google - Facebook TooManyToys

Step Lights;Painted Flanges; Bypass Oil Filter; Heated Mirror Switch; Reverse Lights; 7.3L Fuel Reg Shim; 6 Disc Radio Speed Volume Mod; Coolant Filter, etc.

Last edited by FMTRVT; 06-20-2011 at 07:33 AM.
FMTRVT is offline  
post #3 of 3 (permalink) Old 06-20-2011, 08:40 AM Thread Starter
Senior Member
Join Date: Mar 2011
Posts: 190
My Photos: (0)
Feedback Score: 0 reviews
Thanks Jack. I will definitely use the warning circuit. Cheap insurance.

2000 F350 DRW 7.3
tomlin is offline  
Sponsored Links

  Diesel Forum - TheDieselStop.com > Other Topics > Wheels, Tires, Brakes, and Suspension

Quick Reply

Register Now

In order to be able to post messages on the Diesel Forum - TheDieselStop.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome