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Topic: Burning Brakes, and a dangerous ride down the mountain (Read 329 times) previous topic - next topic
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Burning Brakes, and a dangerous ride down the mountain
Greetings:

I’m asking from advice from those of you who have way more experience with me driving down mountain grades.

We are a 30 IB towing a CRV. 

To prepare for our drive down the hill from Big Bear, an 8400 to sea level drop in about 40 miles, I reviewed my downhill procedures: using tow/haul, 2nd gear for a 6% grade, starting out slow and keeping it slow, using the break no more than a count of 3 and letting it cool off as long as possible.  I did pull over, in hindsight, too often to let others pass us by.  That meant I was using the breaks more than necessary, as I later learned.

Additional information:  We do have a proportional braking system for the CRV and it was on and set to 5 out of 10. 

When we reached the bottom, the temperature was 95 degrees, and we stopped for a break.  At that time, there was a sever smell of burnt rubber so I waited about 30 minutes.  As soon as we took off, I could feel the brakes were VERY SOFT so pulled over again.  We waited another 30 minutes and the breakers were a little better but still not great.  Because of the heat and advice from Dr. Google, I elected to drive slowly keeping loads of distance between me and the next vehicle. We made it home but it was the worst drive of my life.

My questions are:

What could I have done differently?  I know now that I won’t be as kind pulling over to let one or two cars pass.

What advice do you have when I take it into my mechanic to check the brakes?

I sincerely appreciate any and all advice you can give me as this was honestly one of the most frightening experiences of my RVing life.

Thanks!
'O6 IB Anniversary Model
Sue, My Copilot
Carlie, our canine princess
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #1 –
"I know now that I won't be as kind pulling over to let one or two cars pass."

One or two... NO. The law says five (5) or more! Everyone has to 'share' the road.

I can commiserate with you, having experienced much the same situation while driving over Tioga Pass west bound through Yosemite. I smelled brakes long before I reached the Hwy 120 exit. I sat for nearly an hour to let them cool.

When I got it to my Service shop they said there was no apparent problem. Drove for some time after without issue. When the peddle goes soft it sometimes helps to pump the brake some.  ;)
Steve S.
Lazy Bones & Cedar
2004 30'IB (Island Bed)
Yesterday is History, Tomorrow is a Mystery
Live for the day!
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #2 –
Soft brakes can be the result of moisture in the brake fluid. When the brake fluid gets very hot, the water will boil.
When was the last time the brake fluid was flushed and replaced?  I recommend changing it every three years.
Do you have a toad brake and was it functioning normally?

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #3 –
The obvious issue, as you mentioned, was the additional braking it took to pull over and let cars pass.  Without that I think you would have been fine.   I'll remember your experience and just let the cars behind me wait if need be on steep hills.   Frank
plan B - 2023 Travato
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #4 –
Quote from: kool83704  - 
The obvious issue, as you mentioned, was the additional braking it took to pull over and let cars pass.  Without that I think you would have been fine.  I'll remember your experience and just let the cars behind me wait if need be on steep hills.  Frank

I'm not so sure that pulling over, to let faster vehicles pass, caused his soft brakes. We pull a heavy Jeep and have descended most of the major downgrades in the western US without suffering fading, soft or smelly brakes. This includes dropping down from Big Bear on all the major routes. I often pull over to let faster vehicles pass.
I suspect that either Jules's brakes have issues or the toad brake wasn't doing its share.

If you pull over and stop, do not keep your foot on the brake pedal, put it in Park. Holding your foot down transfers a lot of heat into the disc brake pad, from the smoking hot rotor. The pads then transfer heat into the caliper and brake fluid. The fluid can get hot enough to boil, causing air bubbles and a soft pedal. Water in the fluid lowers its boiling temperature, making it more likely to happen. Water in the fluid also causes rust that can damage rubber seals.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #5 –
Quote from: Jules  - 

Additional information:  We do have a proportional braking system for the CRV and it was on and set to 5 out of 10. 

Thanks!

What brand and model?

Steve
2004 FL
2013 Honda Fit
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #6 –
I've had a number of Ford mechanics tell me that the e450 chassis has brakes that are undersized for a full load.

I have had fewer problems since I started changing the brake fluid every 2 years. 

Stay off the brakes when you can, take it slow, and take breaks on long hills.

You might consider separating the toad from the RV and driving it down separately. 
 
Rich
'03 MB in NC
2003 MB
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #7 –
Descending in first gear is  an option. Works for me. My toad brake was inop this summer.
Harry 2006RB
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #8 –
We live on a mountain and have to make a 1,400 foot descent in 3.5 miles (actually less because about a third of that distance is running along a ridge) to get to our valley. Haven’t done it in a motorhome yet but did it in our Tahoe/ HiLo trailer combo before we sold them.

As others have said, using your gears as much as possible and your brakes as little as possible, and having properly functioning and adjusted toad/trailer brakes are imperative. As someone else mentioned, you can at least disconnect a toad from the motorhome; not so much with a trailer combo!
Greg & Victoria
2017 Mid-Bath  “Nocona” towing a manual 2015 Forester
Previously a 1985 TK
SKP #61264
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #9 –
First, thank you all for your excellent suggestions.  I will take them all under advice.

I will be taking my rig to our repair technician to have them evaluate for any damage I might have done to my rig, replacing the brake fluid and repairing any damage.

If and when I ever go back to Big Bear, I won’t be pulling over for one or two cars again, will use first gear more to slow down, and not stop at the bottom of the hill to allow airflow to cool off my brakes. 

To answer a question about my tow system.
What brand and model?
SMI Stay in Play Braking System.

I can’t thank you all enough for your advice and knowledge.  This group is a wealth of information and non-critical support.  I so appreciate each and everyone of you.  Thanks!

Jules
'O6 IB Anniversary Model
Sue, My Copilot
Carlie, our canine princess
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #10 –
Quote from: Jules  - 
If and when I ever go back to Big Bear, I won’t be pulling over for one or two cars again, will use first gear more to slow down, and not stop at the bottom of the hill to allow airflow to cool off my brakes. 

To answer a question about my tow system.
What brand and model?
SMI Stay in Play Braking System.

Make sure the Stay n Play is actually working. When it is activated, going downhill, you should feel it engage, with a firm tugging at the rear bumper.
The unit has vacuum lines that can leak, check the lines for tightness.
The under dash piston, that's mounted on the brake pedal, can loosen and reduce or eliminate the pedal travel when the toad brake is engaged. 
The piston's cable can pull loose from of its firewall clamp, the cable should have no slack but be just loose enough that the brake pedal can fully retract. The clamps that secure the piston to the brake pedal can loosen and throw the cable out of adjustment.

When descending long, steep downgrades, I immediately downshift, finding a gear that holds the engine speed near 4000-RPM,  at the desire downhill speed.
When the speed gets as high as I'm comfortable with, the brake pedal is firmly pressed until the speed is reduced 10-MPH and then completely let off the pedal, the speed will then slowly ramp up and the brakes will cool. Repeat when the speed has gone up 10-MPH.
The brakes are more effective if use heavily for a short time, it allows the rotor to get very hot. A hot rotor rejects heat much faster than a cooler rotor during the cooling period, due to the higher difference between the rotor temp and ambient air temp.
It is important to have as much cooling time as possible, where the brake pads are NOT in contact with the rotor, keep your foot off the brake pedal during the cooling period, while coasting.

The right braking method, using the gears and a properly operating toad brake should get you down any grade safely.
Make sure that the brake pads are replaced that the same HD OEM brake pads. Light duty pads may overheat and fade in severe situations . Change the brake fluid every three years.

Larry

Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
 
Re: Burning Brakes, and a dangerous ride down the mountain
Reply #11 –
Quote from: Jules  - 

To answer a question about my tow system.
What brand and model?
SMI Stay in Play Braking System.


Note that the SMI unit is NOT proportional - it applies the brakes fully when it engages. We tow a Honda Fit, and there is a definite tug we feel when it engages. If you do notice this, the unit is probably either not working properly or not adjusted correctly. However, when adjusted properly, it may still not engage if you are descending a hill cautiously - the brakes in your rig may need attention.

Steve
2004 FL
2013 Honda Fit