FW: [ihc] About those parking brakes .....

[Tom Harais <THarais@xxxxxxxxx>]

Thomas J. Harais, Director of Planning and Grants
ECCTA dba Tri Delta Transit
801 Wilbur Avenue
Antioch, CA  94509
Desk (925) 754-6622 X261
FAX (925) 757-2530
Cell (925) 550-7602
tharais@domain.elided


-----Original Message-----
From: Tom Harais 
Sent: Monday, September 27, 2004 12:43 PM
To: 'Steven Stegmann'
Subject: RE: [ihc] About those parking brakes .....

Steve:

If I understand things correctly, many large trucks and buses DO NOT have
the self-energizing feature on their drum brakes, especially those with air
brakes.  Both shoes move simultaneously and concentrically into the drum
surface.

Of course, all our buses, from the paratransit vans (Ford E350s) to the 45'
over the road coaches (Rockwell rear axles for 60,000 lb GVWR) have disc
brakes all around now.  Don't know if the e-brake is drum or disc.  I have
at least one 4W disc vehicle where there is a small "drum" inside the
wheel/rotor on the rear for the e-brake only. I have another, where the
e-brake levers the rear wheel cylinder so that disc pads engage the rotor.

Speaking of brakes, the Warn retrofit for Dana 44 rear axles that let you go
semi-floating w/disc brakes seemed like a good idea a few years back.  But,
I haven't seen much about them here or elsewhere, so they must not have been
too popular or they may have had shortcomings.  Or, maybe us pragmatic IH
folks just won't spend that kind of money.  What does anyone know about
these?  IIRC I do remember a thread where the wheel bearing was cutting
through the outside of the axle housing (was not designed for "floating")and
Warn was going to make a change in the design to stop that.

Tom H., '76 Traveler