Legality of a hydraulic parking brake

Matt Colie

Matt Colie

Well-known member
Aug 15, 2008
11,101
807
113
South East Michigan near DTW
During a most recent discussion with Dave Lenzi (aka the Wizard), he showed us his prototype of a hydraulic parking brake. During said discussion he
mentioned that there are now, in production, several light truck models that use a hydraulic parking brake. As nearly as he could tell, the
regulation only requires that the parking brake be an isolated system and cannot require the integrity of the service brake to function. This being
the case, he was looking at an independent caliper and master cylinder system.

As I recall, he had these parts at Elkhart, but of that I am not certain.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
Not exactly sure of the legal requirements either but if one wanted to add a second system one just has to look to the "drifting and rally community"
as they already run a separate manually applied rear brake system....it would just be a matter of figuring out a way to couple the current park brake
lever to the pushrod of the secondary master cylinder [the current versions use a handle affixed]. Dang i wish i still had my shop as this would be a
fun one to build up..... :(
--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
Or put in one of these:

epman-high-quality-hydraulic-racing-drift.jpg https://www.dhresource.com/0x0s/f2-albu-g3-M00-9D-68-rBVaHVSjhoaABCcuAAGmoqQvA6A037.jpg/epman-high-quality-hydraulic-racing-drift.jpg

It already has a lock. I added a die spring to keep the pressure up.

Works great.

Dolph

DE AD0LF

Wheeling, West Virginia

1977 26’ ex-PalmBeach
Howell EFI & EBL, Reaction Arms, Manny Transmission

“The Aluminum and Fiberglass Mistress"

>
> Not exactly sure of the legal requirements either but if one wanted to add a second system one just has to look to the "drifting and rally community"
> as they already run a separate manually applied rear brake system....it would just be a matter of figuring out a way to couple the current park brake
> lever to the pushrod of the secondary master cylinder [the current versions use a handle affixed]. Dang i wish i still had my shop as this would be a
> fun one to build up..... :(
> --
> Rich Mondor,
>
> Brockville, ON
>
> 77 Hughes 2600
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Both my Dodge Magnum and my Wife’s Subaru have what we referred to as “Drisc” brakes. There is a disc on the outside for stopping, and a drum on the inside for a parking brake. If someone was so inclined, I imagine a suitable combination of parts could be plucked from the parts bins for our coaches.

-Dave
1978 Transmode near Pittsburgh

>
> Off road/racing use and highway use are two different animals.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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Those of us who live in the Rust Belt know how poor the cable applied parking brakes are. They just rust up and chances are if you get them ON, they
won't come OFF!.

The parking brake on my 2017 GMC pickup is already seized and I expect it won't take too long before the new 2019 is seized too. Yes I was using them
periodically, but you need to be vigilant about keeping the cables lubed... but still its only a matter of time...

There are electrically operated parking brake calipers as well. I'm hoping that will solve our problem.
--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
 
> Those of us who live in the Rust Belt know how poor the cable applied parking brakes are. They just rust up and chances are if you get them ON,
> they won't come OFF!.
>
> The parking brake on my 2017 GMC pickup is already seized and I expect it won't take too long before the new 2019 is seized too. Yes I was using
> them periodically, but you need to be vigilant about keeping the cables lubed... but still its only a matter of time...
>
> There are electrically operated parking brake calipers as well. I'm hoping that will solve our problem.

Yup if i get a bit of time to play with this coach or someone beats me to it, i will have electro park brake calipers on my unit in the near
future....i hate messing with the cables....

--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
Not sure if thats a step forward or backwards.....yes we have disc and Pbrake but we still need cables..... :?

> Both my Dodge Magnum and my Wife's Subaru have what we referred to as "Drisc" brakes. There is a disc on the outside for stopping, and a drum on
> the inside for a parking brake. If someone was so inclined, I imagine a suitable combination of parts could be plucked from the parts bins for our
> coaches.
>
> -Dave
> 1978 Transmode near Pittsburgh
>

> >
> > Off road/racing use and highway use are two different animals.
> > --
> > John Lebetski
> > Woodstock, IL
> > 77 Eleganza II
> >
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
John:

I completely appreciate that.

Nothing in my braking system is as it came from the factory. Not even the front calipers.

Regardless of the certifications obtained by the manufacturer, I chose good quality, made in USA parts, including the “drift handle” that I modified.

It’s single cylinder is from Kelsey Hayes, and I have no reason to believe it’s not the same components as their commercial or certified “highway” product.

It’s completely passive when I’m not using it, so as long as it does not breach, I have rear brakes.

If I pull on it and it fails, I’m no worse off than I was before.

But, when I pull on it and it works, there’s magic!

Dolph

DE AD0LF

Wheeling, West Virginia

1977 26’ ex-PalmBeach
Howell EFI & EBL, Reaction Arms, Manny Transmission

“The Aluminum and Fiberglass Mistress"

>
> Off road/racing use and highway use are two different animals.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
I watch this Thread with a great deal of interest and have been
embarrassed by Matt Colley (Colie) in making some comments.

- All hydraulic alterations (line locks or "kiss" style service brake
assists) are disasters in the making. Why? The seals in our 70's
designed service brake systems were designed for "momentary" duty cycle.
NOT FOR EXTENDED TIME UNDER PRESSURE. A prime example that has been
published in this Forum was utilizing a stick between the steering wheel
and the brake pedal to maintain Service brake application for a Parking
brake. The first service brake application after using this parking brake
methodology resulted in seal "blow by" and a catastrophic rearward rolling
and out of control Coach. (R. Mueller)
- I have modified the Parking brake system on Jim K's coach with an
intermediate 80mm disc brake, and abandoned the intermediate parking brake
cable. This results in a rear wheel parking brake cable to actuate the
rear wheel parking brake only. "Infinitely easier to tune in." Part of
that modification was to remove all OEM Equalizers and replace with
pulleys. With that approach you can tune in the "Lash" in the cable system
to achieve a locked wheel that does not "drag" the service shoes when not
in use.
- The "Pearl Princess" (my coach) is fitted with this arrangement. When
I actuate the parking brake it locks the rear wheels. When I created this
arrangement on Jim K's coach we concluded that driving off with the parking
brake engaged could only be accomplished with total disregard of the
coaches moaning and groaning to proceed. A very good thing!

JUST WHAT I DID........PROCEED AT YOUR OWN RISK.
--
Regards,

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

1977 23'B named "Pearl Princess", HARDLY ORIGINAL, (455 EFI) (Pwr. Drive)
(tailgate) (rear bunk beds)
(Webasto petrol boiler) (MB Elect fan clutch) (Brake reaction arms) BUT
STILL A WORK IN PROGRESS!

ReplyForward
 
Bruce wrote: "Those of us who live in the Rust Belt know how poor the cable applied parking brakes are. They just rust up and chances are if you get
them ON, they won't come OFF!"

I used to live in the rust belt (Massachusetts), and most of my automotive experience was there. In the little town (Pelham) where I lived, the state
used so much salt on US 202 that it polluted wells hundreds of yards away, and the state was forced to buy out and relocate some property owners as no
clean water could be found on their lots. I've had more nice cars rust out under me than I care to remember.

That said, I also recall that Mass. was very strict about parking brakes. Inspection was twice yearly (later annually with emissions), and that
parking brake had to be capable of stalling the engine in first gear at idle (a real problem when diesels came along). I always advised my customers
to set the brake EVERY time they parked, unless parking for a period of days. I said "If you don't use it, you won't have it when you need it,
whether in emergency or to pass inspection." Those that followed this advice, myself included, ALWAYS passed the brake inspection.

The only caveat in regard to GMCs is that they tend to sit for extended periods, so the parking brake shouldn't be left on in that case. (I've seen
brake shoes rust solidly to the drum after sitting for months. Even seen clutch discs rust to the flywheel.) Still, the best advice is to exercise
that brake frequently, and lube the cables if you can.

My .02
Rick Staples

--
Rick Staples, '75 Eleganza, Johnstown, CO

"Advice is a dangerous gift, even from the Wise to the Wise, and all paths may run ill." -Tolkien
 
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