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Re: [oletrucks] 6 lug disk brakes

To: "Hanlon, Bill" <Bill.Hanlon@COMPAQ.com>
Subject: Re: [oletrucks] 6 lug disk brakes
From: jelerath@us.ibm.com
Date: Tue, 15 Feb 2000 11:15:26 -0700

Bill,
I converted my '53 3100 to disc brakes.  They work great.  I went to
pick-n-pull (junk yard that lets you go find what you want and remove it
yourself) and got the front rotor (includes the hub), calipers,
proportioning valve and flexible brake line from a 77' Camaro.  I bought
the adapter kit from Chevy Duty.  I do NOT have any type of vacuum assist.
I even used the old, but rebuilt, master cylinder.  I have had people on
this list state that you "need" a vacuum booster and dual master cylinder
but have not seen a GOOD explanation as to why.  Most of the statements are
speculation.

Prices: Chevy Duty Kit.................$99m (includes mounting plate, some
bolts, bearings and spacers)
              Hub, caliper and rotor...$49 each
              proportioning valve.........$5
              new brake pads..............$15 per pair

Tools:  basic wrenches
              a good torch or a hammer a drift (Craftsman, 1/4" round
tip...flat, not pointed)
              patience
              patience
              more patience

The proportioning valve is also a metering valve.  It is required.   I have
seen new ones priced in the $95-$100 range.  At PNP it is $5.  I think my
rear brakes are from a '55 Chevy (whole axle) and are the narrow shoes.

Camaro's are the best source because they are so plentiful.  Several other
mid-sized GM cars from the mid 70's will also work.  I think any Camaro
from 1974-1979 will work.

There were 3 difficulties in installing the brakes
1. The spacer bushing is a press fit onto the axle.  Alternatively, you can
heat it with a torch to expand it and then slide it on.  I didn't have
access to acetylene, only propane, so my heat wasn't very hot.  On one side
I patiently waited until the spacer was hot enough and it went right on.
On the second, I was too impatient, so I tried to fit it on before it had
expanded enough.  It got part way on and when it touched the axle cooled so
rapidly that it shrank to the axle in the wrong place.  Don't bother with a
torch at that point.  As you apply heat to the spacer, it also heats the
axle so its diameter increases too.  Let it cool and use the old fashioned
"manual press", which is a hammer and a drift to tap all around the
perimeter of the spacer to worry it onto the axle.  This took about a half
hour....I should have waited the extra 10 minutes to get it hot enough to
begin with.  If you have some metal calipers you might try using them to
see when the spacer diameter has increased enough to slip it on the axle
easily.

2. The caliper interfered with the bolts in the steering.  I had to file
(carefully) the backside of the caliper, which is the structural wall for
the wheel cyllinder and faces the tie rods, to get clearance.  This is easy
as the metal is pretty soft.  Be careful you don't put notches in the
caliper (it will create high stress areas) and that you don't grind too
deeply.  You don't want to weaken the metal so much that the hydraulic
pressure from a panic stop cracks the caliper (wheel cylinder wall).

3. The axle tapered too quickly.  When I put the outer wheel bearings on
(they come in the Chevy Duty kit) the ID jamed onto the axle OD slightly
before the bearing was properly seated int the race.  I don't know how to
resolve this.  I am nervous about grinding the axle taper.  I suppose I
could remove the bearing, take it to a machine shop and taper an 1/8" of
the surface along the tie rod side of the ID, or I could try to play around
with spacers on the inner part of the axle.  I was cold, wet, tired and
hungry and it was getting dark so I just left it alone.  I believe it
creates a bit of wander in the steering.  The net effect is the same as if
the axle nut isn't snugged up to the bearing tightly enough.

I love the brakes!  I used to have to, litterally, stand on the pedal to
get the truck to stop.  Although these aren't vacuum assist, they are easy
to use and SAFE.

Jon Elerath
jelerath@us.ibm.com


"Hanlon, Bill" <Bill.Hanlon@COMPAQ.com>@autox.team.net on 02/15/2000
07:38:10 AM

Please respond to "Hanlon, Bill" <Bill.Hanlon@COMPAQ.com>

Sent by:  owner-oletrucks@autox.team.net


To:   Oletrucks <oletrucks@autox.team.net>
cc:
Subject:  [oletrucks] 6 lug disk brakes



Anyone out there had good or bad luck converting their TF
front brakes to disks?  I want to keep my 6 lug wheels,
convert from ball to roller bearings and put on a dual
master cylinder while I am at it.

Is a power booster really necessary?

Who's kit did you use and are you happy with it?

What components (make and model of the rotors and calipers)
     did your kit use?

What parts were required that did not come with the kit?

Was your installation more than a "wrench" job?  Any
     special tools required?

Were external-to-the-master-cylinder "residual" valves required?

Any and all comments appreciated.

oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959



oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959

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