Community Forums

Bilito · 04-23-2012, 12:11 PM

The link about my brakes failing got me to thinking.

My rig does not have a handbrake, It has a huge brake drum assembly behind the tranny.

How does that work? Must it be bled? How can it be used in the event of an EMERGENCY LIKE THE BRAKES FAILING?

I know the tranny must be in Park for it to engage, How does it release? Does it release when you put the tranny in gear?

Heck I don't even know if it works, I am on level ground

All I know about it is that it uses dextron transmission fluid and I have two pumps, one is the power steering and the other is for the brakes

winnymini · 04-23-2012, 12:23 PM

well more info is needed. Chassis year and make would help with a reply... My E450 ford has a big drum brake on the rear of the tranny that is operated by a foot pedal on the left side of drivers peddles and a hand release under edge of dash right above the peddle. It was made to immobilize the vehicle but i would use it in an emergency.

Bilito · 04-23-2012, 12:43 PM

Quote:

Originally Posted by winnymini

well more info is needed. Chassis year and make would help with a reply... My E450 ford has a big drum brake on the rear of the tranny that is operated by a foot pedal on the left side of drivers peddles and a hand release under edge of dash right above the peddle. It was made to immobilize the vehicle but i would use it in an emergency.

It's a 91 Oshkosh with a Ford 460, no foot pedals, no hand release, just a park position on the gearshift selector

Possum · 04-23-2012, 12:54 PM

Isn't there a double action brake handle beside your driver's seat? Grey or Black with a double fold so that you get a strong mechanical advantage when you pull up on the lever.

Bilito · 04-23-2012, 01:01 PM

Quote:

Originally Posted by Possum

Isn't there a double action brake handle beside your driver's seat? Grey or Black with a double fold so that you get a strong mechanical advantage when you pull up on the lever.

no handles of any kind nor is there any eveidence of there ever being one there

winnymini · 04-23-2012, 01:25 PM

Must be missing something (You or the MH ) Mine wont let me put out an extension or leveling jack without the Brake being set. Wish I could look for you.

Bilito · 04-23-2012, 01:36 PM

Quote:

Originally Posted by winnymini

Must be missing something (You or the MH ) Mine wont let me put out an extension or leveling jack without the Brake being set. Wish I could look for you.

All I understand is that putting it in park sets the parking brake, I was wondering what happens if one day I lost the brakes, how do I stop it.

Bilito · 04-23-2012, 05:16 PM

Quote:

Originally Posted by Bilito

All I understand is that putting it in park sets the parking brake, I was wondering what happens if one day I lost the brakes, how do I stop it.

I found in a manual that I have a shift lever parking brake release system. By placing the lever in park a spring system sets the brake shoes against the drum, To release I must have the motor running to have hydraulic pressure to release the brake and yes it does describe how to bleeed the system.
It does not say anything about an emergency braking system in the event of a failed brake system. I will have to print out the whole thing in an attempt to understand if I can throw it into park in an emergency or what. I hope someone here has the answer, I have never seen a system without a foot or hand lever to set the brakes.

ccook129 · 04-23-2012, 08:50 PM

http://www.irv2.com/forums/f22/p-30-...ake-94816.html

wa8yxm · 04-24-2012, 09:27 AM

That is called the auto park system.. Frankly I'm not all that pleased with it.. But if you watched the movie RV.. That's what Robin Williams Damaged when he hit the mail box which led to a bunch of gags later in the movie.

As you found it is activated by putting the tranny in PARK, in this kind of tranny there is no park pawl so you can put it in park in motion.

I DO NOT RECOMMEND DOING THIS howver as you have very little control over this system, it's either on or off, and if you lock it up in motion your motor home is very likely to roll over and take a nap.. They are not supposed to do that.

Bilito · 04-24-2012, 10:04 AM

Quote:

Originally Posted by wa8yxm

That is called the auto park system.. Frankly I'm not all that pleased with it.. But if you watched the movie RV.. That's what Robin Williams Damaged when he hit the mail box which led to a bunch of gags later in the movie.

As you found it is activated by putting the tranny in PARK, in this kind of tranny there is no park pawl so you can put it in park in motion.

I DO NOT RECOMMEND DOING THIS howver as you have very little control over this system, it's either on or off, and if you lock it up in motion your motor home is very likely to roll over and take a nap.. They are not supposed to do that.

I guess it might be OK to test it by going just a few miles and hour, say barely walking speed and put it in park to see what happens. It should stop quickly, I think???

wa8yxm · 04-24-2012, 04:45 PM

Let me put it this way: Some years ago I used to see ads on TV "Do you know what that sound is? It's the sound of a man who knows where he's going".

It was the sound of a big diesel engine.....at full idle,,,, he was going nowhere

The ads were for an outfit called "Chauffer's Driving School" (This was back before CDL)

Well, turns out there are a few real Chauffer's Driving schools.. These come in two types.. One teaches you to drive so you don't spill the coffee in the back seat (OK so it's "Cold Coffee" (booze) back there oten as not). The other tells you how to spill your chase car (Evasive and hyper defensive driving) That one is called "SKID SCHOOL"

How to they put the car into a skid for you... by locking up the emergency brakes.

I would not wish to try that on a motor home, even at walking speeds.

4brv · 05-16-2012, 08:44 PM

as no one yet has awnsered your question fully:

yes this is a hydraulic release brake, yes in an emergency it will slow the unit however it was designed to hold not stop therefore its not going to be a quick stop. to test, FIND A HILL!!!! DO NOT throw the unit into park at any speed except as last ditch emergency, you will damage the reverse solenoids in the transmission valve body. $$$. they are a bit of a pain to service but simply if you can park on a fairly steep road and not roll you are good to go.

simple form:(LOL)
yes it will stop you
park = parking brake
no you wont skid out of control, way too much rotating mass for such a small drum.
if you do have to use it as emergency, it needs to be pulled apart and inspected. the heat usually kills them.

if you would like anything more please feel free to e-mail me
4brv.wasaga@gmail.com

James

Bilito · 05-17-2012, 05:16 PM

Quote:

Originally Posted by 4brv

as no one yet has awnsered your question fully:

yes this is a hydraulic release brake, yes in an emergency it will slow the unit however it was designed to hold not stop therefore its not going to be a quick stop. to test, FIND A HILL!!!! DO NOT throw the unit into park at any speed except as last ditch emergency, you will damage the reverse solenoids in the transmission valve body. $$$. they are a bit of a pain to service but simply if you can park on a fairly steep road and not roll you are good to go.

simple form:(LOL)
yes it will stop you
park = parking brake
no you wont skid out of control, way too much rotating mass for such a small drum.
if you do have to use it as emergency, it needs to be pulled apart and inspected. the heat usually kills them.

if you would like anything more please feel free to e-mail me
4brv.wasaga@gmail.com

James

I have a small knoll in my side year the LF tire goes up on which tells me I drove too far into the yard. Last week I drove it in till it started to go up the knoll put in in neutral and just as the RV started to roll back I put it in park and it stopped dead. I still have to bleed that park brake,
I found a set of instructions in the manual how to do that. Will get to that after I finish the interior, I want to re-bleed the brakes anyway.