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Topic: Parking brake update (Read 619 times) previous topic - next topic

Parking brake update

My son just sent me pics of said brake.  It IS on drive line and DOES provide for adjustment. Now maybe we can accomplish something!

Jim
'92 Grand Villa 36' w/8.3Cummins mechanical
ORED
Build#4062

Re: Parking brake update

Reply #1 –
Sent pics to MIchelle - hope she will post them for me. next for me to learn is how those shoes are activated. Operators manual tells me to shift to neutral, hold service pedal down and  flip switch to set brake.

Jim
'92 Grand Villa 36' w/8.3Cummins mechanical
ORED
Build#4062

Re: Parking brake update

Reply #2 –
Son just was under chassis again. We thought hydrolics pushed levers down to set but he watched as grandson flipped switch and he said lever went UP during set.(Brake must have been set during pics We talked a bit and recalled coach had been driven a few miles with switch in set position and that the PO had reminded us to not do that - wonder how he knew? Maybe all we need is a new set of shoes!? Sorta like the episode I had recently in learning my fuel tank was empty!! Grandson says shoes look to be about 1/4 in. thick.

Jim

With movement when switch is operated, things must be working up front of brake pedal?
'92 Grand Villa 36' w/8.3Cummins mechanical
ORED
Build#4062

Re: Parking brake update

Reply #3 –
CCC_Email <fcccservice@daimler.com>
To:Jim Sizemore
Oct 11 at 9:58 PM

There are no manuals that we can give you for the Oshkosh units. They closed there publications in 1995. The park brake is simple. It allows hyd fluid from the tw11 valve, when applied, to go to the park brake canister near the drive shaft. This canister then will fill and activate a piston that will apply the brakes to the driveshaft.


Sincerely,
Glenn Hoops
Representative

Case =  87089

Jim
I could not understand having to depress service brake to set park brake. Now we know...
'92 Grand Villa 36' w/8.3Cummins mechanical
ORED
Build#4062

Re: Parking brake update

Reply #4 –
If you drove "a few miles" with the brake set, the pads (shoes) might be glazed.  If you can figure out how to remove them, they would probably clean up with a bit of work.  Degrease with brake cleaner, then use emery cloth to scuff them up.  (at least that's the way I've seen it done).
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Parking brake update

Reply #5 –
Drive shaft parking brake I thought was spring applied?  You have to have hydraulic pressure from the motor or aux pump to release it.  Fails on.  Not off
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Parking brake update

Reply #6 –
Quote from: Caflashbob –
Drive shaft parking brake I thought was spring applied?  You have to have hydraulic pressure from the motor or aux pump to release it.  Fails on.  Not off


That is how I recall.  I had a 1988 Winnebago on a 1987 John Deere (later became Oshkosh) chassis, front engine Ford 460 gas. It had the Bendix parking brake and service brake system.  It used hydraulic pressure from a second power steering pump to power both the service brakes and release the parking brake. Placing the shift lever in Park applied the parking brake via spring action.  Pulling the release knob with the engine running and shifted you of Park would start the hydraulic pump, releasing the brake.  I do recall the service brake needed to be applied for something, as an interlock.

For what it's worth, I have a failure within the warranty period.  The hydraulic fitting to the parking brake was cross threaded, and let loose, draining all the hydraulic fluid used for the parking brake and power brakes.  I was able to stop with the electric motor backup system on the service brakes, but the parking brake was toast.  It tried to engage while I was driving, and needed to be replaced.
Tom Lang K6PG (originally  KC6UEC)
and Diane Lang
2003 38 U295 build 6209
2016 Jeep Grand Cherokee Summit Ecodiesel
still have tow-ready 2006 Acura MDX 
Temple City, California
Motorcade 16681 California Chapter President
SKP 16663 member of SKP Park of the Sierra, Coarsegold California
FMCA F071251
Retired electrical and electronic engineer

Re: Parking brake update

Reply #7 –
Grandson just moved the coach. Noticed that park brake tension changed with pressure on svs pedal, Not much, but perceptable. Looks like brake fluid will go from master cyl. to the valve mentioned by freightliner on its to the back of the coach. Will post more about this when  I learn more.

Jim
'92 Grand Villa 36' w/8.3Cummins mechanical
ORED
Build#4062

Re: Parking brake update

Reply #8 –
Quote from: Caflashbob –
Drive shaft parking brake I thought was spring applied?  You have to have hydraulic pressure from the motor or aux pump to release it.  Fails on.  Not off

Does the spring application only apply with air brake systems??

Jim
'92 Grand Villa 36' w/8.3Cummins mechanical
ORED
Build#4062

Re: Parking brake update

Reply #9 –
Quote from: Jim Sizemore –
Does the spring application only apply with air brake systems??

Jim

Jim,

No, that method of application (spring applied) and either air or hydraulic pressure released is common.  It addresses the basic requirement-- fail-safe is, the brake is ON.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Parking brake update

Reply #10 –
So is freightliner correct that mine is set byservice brake pressure thru the TW11 valve. If so, how does it remain set when pedal pressure is stopped(and it does!)I thought freightliner straightened me out - but now I am confused again...

Jim
'92 Grand Villa 36' w/8.3Cummins mechanical
ORED
Build#4062

Re: Parking brake update

Reply #11 –
Look up "line Lock" or "tow truck brake" .  Small electric solenoid that keeps the line pressure on  until  button is pushed.
 Sounds like you could use one in place of the system you have now.

Re: Parking brake update

Reply #12 –
I'm still confused. Mine sets when I apply svs brake and releases when I apply pedal and turn switch(valve?) off. Just doesn't seem to hold like my '68 Travco. I'm probably chasing a ghost as I've heard this complaint from others?

Jim
'92 Grand Villa 36' w/8.3Cummins mechanical
ORED
Build#4062

Re: Parking brake update

Reply #14 –
Thanks, Michelle,

Good pictures of the drive line brake itself.

But, follow the cable "up" to see what activates it. 

Said another way, that cable could be "powered" by a straight mechanical linkage, hydraulic pressure or air pressure.  I know of coaches with each of those choices. Not necessarily better/worse, just different.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Parking brake update

Reply #15 –
It looks like the adjustment rod has been run down quite a ways. Probably need to have the shoes religned.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins
 

Re: Parking brake update

Reply #16 –
I have not been under there but both my son and grandson say that that rod comes thru a rubber boot from a tank/ container with what looks to be a hydraulic line feeding it. This follows the info from freightliner. I'm still having trouble understanding what keeps pressure there after svs. pedal is released. That valve on the dash has what I was using for a switch toggle but it is a lever. Must hold the valve so pressure can not go back thru it? I'll try to look myself tomorrow. We have backed the coach up onto a concrete slab to make getting under easier. That could explain having to depress svs. pedal before switching to set?? Still just guessing...Thanks again , Michelle

Jim
'92 Grand Villa 36' w/8.3Cummins mechanical
ORED
Build#4062