Are rear brakes critical?

[steven korson]

How about thoughts on this one....

How much stopping power comes from the rear?

When I used to call on the GM testing facilities in Lansing Michigan
I had an engineer tell me how they had a number of vehicles with
ornamental rear breaks. Apparently 95%+ stopping power came from
the fronts. They proposed removing them an a model but the government
wouldn't allow it. (He sounded serious.)

Also I lost a front brake line on my Astro Van on the highway last year.
I found out when I went to slow down I hear a weird noise from the back
and I didn't stop. The puff of smoke and the smell told me I was making flat
spots on my rear tires. It took me forever to coax it to a stop.

Has anyone ever ran without either front or rear brakes?

Steven
Rockford MI

 

[david l greenberg]

>Has anyone ever ran without either front or rear brakes?
>
>Steven
>Rockford MI

Yes, once when my mster cylinder failed! (g)

David Lee Greenberg
GMC Motorhome Registry
FMCA Voice Mail: 800.445.1732
F22009

 

[patrick flowers]

>
> How about thoughts on this one....

I sure hope they're important 'cause I recently spent a pile o' money to
improve mine. Seriously, even tho' the majority of braking is done
by the front, the GMC's rear brakes are designed to "lead" by the delay
built into the combination valve. With a vehicle as big as our coaches
and the front axle so far in front of the center of mass, there's a very
real possibility of the vehicle swapping ends if the front brakes are
fully functional and are applied without the rears operating first.
Disc brakes operate quicker than drum brakes and the delay function
allows the wheel cylinders to extend and make contact with the drums
before pressure is applied to the caliper.

Some people remove the combi valve when upgrading to rear disc brakes
theorizing that all six calipers apply equal force at the same time.
Could be, but I left it in place on mine(actually replaced it with a new
one that I already had on hand); figured it couldn't hurt.

> Has anyone ever ran without either front or rear brakes?

Yes - when my rear brake line rusted out, I sealed off the broken
section and drove about 1.5 miles to a garage. I don't recommend it for
the faint of heart and I never got above 15mph. I could stop it, but it
took a lot of advance planning and no small amount of prayer.

Patrick
- --
Patrick Flowers
Mailtoatrick

The GMC Motorhome Page
http://www.gmcmotorhome.com