From: Jim & Pat Winne (jwinne@nettally.com)
Date: Wed Nov 13 2002 - 19:00:38 PST
Hi David and Listers;
I had a wheel cylinder on the M-715 give out while I was out running
around. Being a single master cylinder system, the pedal just went to the
floor with an alarming thud. After the initial shock (seemed like a couple
of minutes of terror) I got to thinking again. The truck is geared so low
that just taking your foot off the accelerator has the same affect as
braking moderately. I down shifted to the next lower gear when needed and
very carefully eased the clutch out. Once in second gear, I was faced with
coming to a full stop and very carefully pulled on the hand brake, easing
the truck to a stop. The hand brake was not very happy about this but
stopped me OK. I drove home through traffic this way, being very careful
to leave plenty of space between me and the car ahead. The truck handled
this way pretty well and got me home without any disasters. What had
caused the failure turned out to be one of the wheel cylinder push rods
that extends the brake shoe. It split an ear off one side which allowed
the cup seal to float instead of push against the shoe. Once I fixed the
wheel cylinder, I had to adjust the hand brake ring as it had a surprising
amount of wear for the short time I had used it. It did the job but like I
say, it wasn't happy about it.
Remember, be careful out there (especially with a Deuce or bigger) # 8^O
Jim(KB4IVH)
MVPA#17216
At 09:19 11/13/2002 -0500, ddoyle9570@aol.com wrote:
>In a message dated 11/13/2002 9:01:13 AM Eastern Standard Time,
>super_deuce@hotmail.com writes:
>
> > Question: Has anyone tested the hand brake at any speed other than for
> > parking?
>
>I suspect that somewhere around here I have an APG test report that
>addresses this. I'll see what I can dig up.
>I do have in front of me at this moment the specifications for the 5 ton
>trucks. The parking brake is refered to as just that, a parking brake
>(not an emergency brake)...it says: "Application of the hand brake shall
>hold vehicle motionless on a dry concrete 40 percent grade, when deaded up
>or down grade with rated payload less towed load." The parking brake
>shoes are the same on both the G-742 and G-744 series trucks, so I suspect
>performance to be the same. It been a long time since I studied any of
>this type thing, but I suspect the forces required to hold 30000
>stationary on a 40% slope are minor compared to those required to bring
>20000 lbs at 50 MPH to rest.
>
>How good is it at slowing the vehicle in case of service brake
> > failure?
>
> > Also, has anyone ever experienced total brake loss with the
> > deuce?
>
>Not with a deuce....I have lost power assist on a M62 five ton wrecker
>(makes a believer in power assist out of you), and I have had a total
>brake failure in an M123A1C ten ton tractor. I can tell you for a fact
>that at 30 miles per hour with no brakes in one of those, the parking
>brake lever is just something else to hold onto.
>
>Regards,
>David Doyle
>
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