Community Forums

jacksonjdnc · 01-02-2014, 07:51 AM

Can you stop the coach in an emergency by applying the parking brake?

mel s · 01-02-2014, 08:11 AM

Quote:

Originally Posted by jacksonjdnc

Can you stop the coach in an emergency by applying the parking brake?

Most "parking brakes" will not effectively stop a coach, (but in an emergency a parking brake is better than no brakes at all).
Mel
'96 Safari

319DSF · 01-02-2014, 08:19 AM

Hope I never have to find out.

homeless · 01-02-2014, 08:20 AM

I would suggest you try it when your on a lonely road or hill by yourself!

halfwright · 01-02-2014, 08:23 AM

I think that it will---if you have time and room.

nctox · 01-02-2014, 08:25 AM

Quote:

Originally Posted by jacksonjdnc

Can you stop the coach in an emergency by applying the parking brake?

Yes. At Camp Freightliner they show a video of a 40'er, IIRC, being stopped by applying the parking brake (air brakes). It was a demo performed by FL and not intended to be something for normal use. It did not lock the brakes. but it did stop the motorhome rather abruptly. About the reaction I would expect if one really stood on the brake pedal in a real emergency.
If your question refers to hydraulic brakes, then disregard the above. I don't know.

AFChap · 01-02-2014, 08:29 AM

Welcome to the forum! If it is working properly, the parking brake will stop the coach, but not nearly as fast (as effectively) as properly working foot brakes will. You would not want to rely on "emergency" application of the parking brake to avoid hitting something on the road in front of you.

jmckinley · 01-02-2014, 09:23 AM

If it's air brakes, it's only the rears and about 50 % of the service brake torque. With no front brakes and only half the rears, you can expect about three times the stopping distance of a full system. And -- the ABS doesn't work on the spring brakes so on slippery surfaces there is the risk of locking the wheels and spinning out.

If it's hydraulic brakes it's most likely a driveline mounted single drum brake designed for parking not stopping. Not a lot of torque anyway and not much lining area. It will fade dramatically during a stop from highway speed and may even destroy itself.

wa8yxm · 01-02-2014, 11:50 AM

Depends on the coach.. And the brakes.. There are Emergency and parking brakes on some coach.. Parking brakes on large vehicles are normally mechanical brakes (Meaning no hydraulics or air) and operate on the drive shaft.. These may stop the rear wheels, and doing that may cause an "End swap" (Or they may not have the power to do it).

Blowing the air tanks on a vehicle with air brakes will usually lock 'em all up, all 4 corners. This is also not the best option for stopping, but you are less likely to have an end swap.. May tire the rig out though and when it gets tired it rolls over to take a nap.

Yes, I know I'm making light of a very serious accident. But you may well remember what I type better that way.

Best advice: When I first learned to time the space between vehicles I was told 2 seconds, now they say 3.. With a MH on dry pavement, try five.. OR MORE epically if wet.

And if you do not have aux braking system on your towed... DOUBLE IT.

C&SL · 01-02-2014, 01:34 PM

Quote:

Originally Posted by wa8yxm

Blowing the air tanks on a vehicle with air brakes will usually lock 'em all up, all 4 corners.

What do you mean? "Blowing the air tanks"
There are no spring cans (brakes)on the front of air brake system that I know of.
So not sure how all 4 will lock up?

Dynasty_09 · 01-02-2014, 03:51 PM

Yes, I beleive there is a spring in each wheel. The air is pushing against it for braking. So all four Wheels would lockup of you loose both tank.

palehorse89 · 01-02-2014, 04:07 PM

Maxi brakes on drive axles only..........

terry735001 · 01-02-2014, 04:33 PM

if you have high miles on your brake shoes to where the adjuster is all most maxed out you can roll the cam in the system doing this

rolling a cam well unluck / or lock up the system and well have to be pulled apart on the side of the road to get moving again .. giving what type of air system you have /cam

on really used brakes full on try getting the brake drum off on the side of the road or in a shop not fun

this is a test i would not try or play around with as you know that it well work if you need them in an emergency

njs42 · 01-02-2014, 05:11 PM

Good thoughtful question for you to ask now as you have.

As stated before some emergency brakes are a smallish brake unit on the drive shaft. Mine looks to be about 12 inches in diameter, I can't imagine it would be of much help stopping 12 tons rolling downhill. It might forestall a bit but I would not be at all surprised if overheated in seconds and became ineffective.

A lot depends on the function and design of your particular parking brake. Something good to find out now if you have never thought about it; I found out about mine when it became an issue. Before that I had never seen mine.