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Re: [GMCnet] Drum brakes [message #329043 is a reply to message #329038] Sat, 10 February 2018 16:18 Go to previous messageGo to previous message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma:
Senior Member
Tom,

"Ask Rob Mueller about his run away coach experience."

I don't remember a run away coach experience. I did have a P-10 master cylinder fail on our first tour but it was at low speed and I
was able to stop the coach and fix the problem by replacing the master cylinder.

Double Trouble came with 6 wheel disks; OEM on the front, Caddy disks on the middle / rear; and no parking / emergency brake. In
order to pass NJ inspection I had Ken Frey swap the rear disks for drums, hook up the cables, and install rebuilt 80mm calipers on
the front and middle calipers. I have been quite happy with the way it stops. So much so that's the braking system the Kingsley will
run.

The day before I took Double Trouble for inspection I adjusted the shoes and the brake cables and adjusted the knob on the end of
the brake lever to put the max tension on the cables. I watched the inspector strain to pull the parking brake on before he ran the
test and was very happy when it passed.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808



-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Thomas Pryor
Sent: Sunday, February 11, 2018 7:51 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Drum brakes

Yeah, its me again the guy that brings reaction arms to your rear wheels
without disturbing the hydraulics or the parking brake.

For my coach, a modified 23B that has only been driven about 5000 miles
mostly to Rapid City, SD and is now up on blocks in my garage here in Lake
Wales Fl. I am doing more mods and will share in future. Upon my return
from Rapid City to Florida, I had the fortune ( misfortune) to tailgate
Uncle Ken Henderson in his 23B with a Cadillac engine and all wheel disc
brakes and effective but legally questionable "line lock" parking brake.
Why questionable?.....sustained pressure on brake cylinder seals that were
designed to see only momentary duty. As Rob Mueller about his run away
coach experience.

That said, I was mostly able to keep up with him over hill and dale with
effective braking and acceleration. (note: 120k on my 455 with Caspro
power drive) My rear brakes were standard drum brakes with no reaction
arms at the time.

A couple years back when I visited Jim K in Calif I modified one of his
coaches with the following:


- INTERMEDIATE WHEELS were modified to use the GM3 caliper and yellow
pads. A GM3 caliper is the same 80MM caliper body used on the Front wheels
of our coaches. The intermediate wheel was fitted with a reaction arm.
- The rear wheels were also fitted with a reaction arm but remained as
stock configuration drum brake.
- PARKING BRAKE CABLES were modified to include pulleys at all
junction points. The dual cable that actuates the both rear and
intermediate brake shoes was abandoned. A new cable extension was
introduced that ONLY ACTUATES the rear wheel brake shoes.


I then tuned the parking brake to eliminate all "LASH" in the cable
system. I followed a very specific sequence and ended up using a 12"
extension on the PB lever to get it "OVER THE TOP"............ that
stretched the cable even more. I then released some tension at the top of
the parking brake handle to achieve a no drag condition on the rear brake
shoe. Jim & I then took the coach for a drive and skidded the
intermediate tire in some aggressive stops. we were both happy with the
service brake enhancement. note: With the reaction arm the rears skidded
also.

We then turned our attention to the Parking brake. I instructed Jim to
engage the parking brake, rock the coach front to rear. He took direction
well and then proceeded to drive off as many owners do with the parking
brake engaged. IT TOOK 3000 ENGINE RPM TO MOVE THE COACH. I told Jim at
the time with the transmission groaning, I could not see how even the
most inattentive owner could drive without releasing the parking brake.

Alas, I had to catch a plane back to Fl and no further assessment was done.

So with my coach being prepared for test launch this summer my Brake system
will consist of:


- new SS brake lines
- new Proportioning valve
- swap front to rear brake lines out of Master cylinder
- Front discs as original with yellow pads
- Intermediate with front disc calipers and discs.......yellow pads and
reaction arm.
- The rears will be stock drums and probably no reaction arm. I will
not plumb the rear wheel cylinder. The rear drums will function ONLY as a
parking brake. I have located some very aggressive brake shoe material
intended for aggressive holding power, not for service brakes use.


JWID.

BTW, Can anyone "report out" using the Chuck Algaur (sp?) intermediate
12" disc system and eliminating the rear drum to be used a parking brake
only?





Regards,

Tom Pryor
4188 Limerick Dr
Lake Wales, Fl 33859
Cell 248 470 9186

Living on a waterfront is not a matter of life or death. Its more
important than that.
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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
 
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