Downhill with disk brakes

RobMcClain

RobMcClain

Member
I am new to disk brakes on a boat trailer and our Venture 23' sits on a dual axle Magic Tilt trailer equipped with 4 disk brakes. I have read about being careful when on a long steep downhill grade so not to overheat the brakes, and I would be interested in hearing from others how you handle this. For example, when going over the Siskyiou Mountains on Highway 5 - a very steep downhill in both directions - how do you keep from not frequently stepping on the brake pedal? We haven't had any experience in this regard yet, but we do plan on doing that grade, among many others. In fact, we live on the top of a long steep hill so when we finally get the boat home we'll experience this issue very quickly. Any guidance would be most appreciated.

Rob
 
Most of us who do long distance towing that includes lots of long grades have converted to Electric over Hydraulic brake actuators. The brakes are only applied if you are depressing the pedal rather than the surge brake actuator keeping the brakes applied for miles at a time. Most new tow vehicles are equipped with built in actuators if ordered correctly. It's not a hard modification.

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My 2 cents:

The hot setup with a heavy trailer is electric-over-hydraulic trailer brakes - maybe unnecessary with a CD22.

From 20 years of towing in mostly mountainous country with surge brakes, first with a CD22 and a manual transmission SUV, and then with our current 12,000 lb boat trailer and a 5-speed manual diesel pickup:

We slow down and gear down before we start down a major hill. Gearing down makes the engine provide some resistance, to help the rig not get going too fast. Of course this is more effective with a manual transmission. I understand some automatics are better than others for this - I have very little automatic towing experience.

On most long steep downhills we're down in 3rd, which maxes out at about 40 mph. On the steepest ones we're in 2nd, which maxes out at 25 or so.

Be conservative (meaning slow), and take a long time to get down the hill if it's a tough one, or if you don't know how tough it's going to get.

If you never let too much speed build up, gently resisting with the engine, the surge brakes may not get activated. If you do have to use the brakes, don't ride them - they'll just keep getting hotter. Use them briefly, and really step on them if necessary to get the speed back down and allow you to downshift one more gear, then let them cool off.
 
Towing your cc-23 should weigh in about 5000-5500 lbs . When towing long distance we usually make sure 60 gallons of fuel is way down less then a few gallons and dump the water 20 gallons This will make up over 500lb of weight that you don't need for towing . Then make sure you use the proper gears for towing down hill . Going up to Tenn. from Florida we would use 3rd gear (5speed auto). in the mountains. If you plan to trailer in the mountains a lot. Go and get the elec over hydraulic and you will have a lot less drama towing

Years ago I worked as a mfg rep for Continental trailers in Miami we were just getting the elec over hydraulics I can attest they do work very well . I dont have them because I only tow once or twice a year in florida good Luck with boat tow .YOu are going to love the cc-23 Jim
 
If I am facing a long downhill grade I will often slow down at the top, just before the grade begins and downshift so I can use engine braking more than the surge brakes. It seems to work OK but I would really rather have electric over hydraulic as Roger suggests.
 
I do not have E/H brakes and have towed both the 22 and 25 over most Western Grades, including to Prince Rupert. No problem with the Siskyiou. However I have seen a number of truckers smoke their brakes on this grade. The secret is as above. Slow down at the top of the pass. I often go down to 30 mph (by letting off the accelerator at the top--and then never letting the speed build up over 50). If you have to apply service brakes then only light taps, no prolonged heavy use after the speed has built up. Generally North Bound, on the Siskyiou, I apply the brakes once or twice. However, my current truck with 6 speed tranny and locking torque converter handles most of the breaking with the engine compression. I would check the temp of the discs and hubs at the end of the down grade--first rest stop. The only time I got into trouble is when I didn't do this on the down grade outside of Ogden UT S. Bound with the 25 (I 15). I had one of the axels disc's dragging and heated the bearings....Not entirely sure why that all happened. However this year, we did the same grade, with a single axle 22 and no heat up. So I conclude that there was a problem with the calipers not releasing on the other trailer (had those brakes rebuilt before the boat was sold).

As for the weight of the 22--we try and keep our below 4500 lbs scale weight including trailer (have weighed it) since we have a single axle trailer rated at 5000 lbs. We towed over 5000 miles so far this year, with no problems. We do check the bearings and wheels regularly, as well as regrease the bearings after every 2500 miles.

One of the members had a trailer reworked, and apparently the castle nuts were set up too tight. It not only caused heating of the bearings, but also decreased his fuel economy. This is one reason I use an IR thermometer, rather than just the finger test. The absolute temp is not as important as the comparison of other wheels, tires, hubs and brakes. (I check the truck as well as the trailer). To check the nuts, it is advisable to jack the tire off the ground, land be sure that the wheel spins freely. This only takes a few minutes, and can save a lot of heart ache, and sore back down the road!
 
To reinforce dreamer, the 1st reply, I wore out a set of disk brakes in two years - less than 10,000 miles. They were surge brakes and there is no way to get them off when going down hill. Between here and Puget Sound I do two long down grades and our local lake has a steep grade coming home. Consequently I seem to always be going down hill. I've since converted to electric over. Much better.
Chuck
 
Guess I need to do some meaningful research on electric brakes to understand them much better, and on hydraulic ones too... If it looks like we're going to hit a lot of grades it might be worth the change. I think our Toyota Sequoia is already equipped with the wiring for an actuator. The posted comments on hydraulics mirror what I've read so far and it is nice to know there is consistency.

I am so looking forward to getting to know the boat and trailer. It is now 1/2 way home - at our daughter's house in Texas, just professionally hauled there from Florida using Cory and Jeff Millard. They were both great to work with. In 3 weeks my wife and I will drive to Texas to pick up the boat and tow it home to the Las Vegas area. We can't wait!!!!!!!!!

Rob
 
I thought I would post back to this thread since I recently crossed the US with surge/disc brakes on a tandem-axle trailer with a 22' C-Dory. Having read a number of informative posts here, I was aware there could be an issue of brake overheating because the brake actuator would "think" it should continue braking due to the pressure caused by heading downhill (it would press into the receiver/ball due to gravity). Knowing that in advance was helpful, so thank you Brats.

I towed with a 3/4-ton van, so it was a decently heavy vehicle - but the transmission is only a 3-speed with overdrive, so nothing special. I had four "serious" passes to contend with: Bozeman Pass, Homestake Pass, Lookout Pass, and Snoqualmie Pass, and I was more than a bit nervous! I did have one 5%, 4-mile "practice" grade in the Appalachians, and quite a few decent hills and dales in the foothills of the Rockies.

What I found was that if I crested the pass slowly (<45mph), I was able to hold the downhill speed on a 6% grade (which these were) at around 40-42 mph with engine compression only (i.e. virtually no braking - once or twice I got up near 45mph and put on the brakes briefly). For my vehicle this meant 2nd gear (I experimented with 1st, just to see, and that kept me at a much slower speed - maybe 15mph). I don't know that I would have wanted to go any faster in any case, although I'm certainly a mountain-pass-towing amateur, so don't take my word as gospel.

Based on this one experience, I no longer feel the immediate need to change over to electric-over-hydraulic brakes for my towing combination. Initially I did want them - it's just that the trailer shop I was at had never installed them before, so I decided to hold off.

I can imagine where those with different tow/boat combinations and/or who are making frequent trips through the mountains might feel differently - and perhaps I will too after more towing. But I figured I would add my data point since I was really glad to read the info from others as I was getting ready for the trip.

Sunbeam
 
This is very helpful feedback Sunbeam, thanks for the follow-up. We will have our first opportunity in this regard in a few weeks and our confidence is improving based on the knowledge provided by you and the other Brats. This is a great website!

Rob
 
Just one other little bit. Earlier I said that I slow down at the crest to be able to downshift. I do one other thing, if I find I must brake I try to slow down enough that I can goose the gas enough to feel the trailer pull back, I think that releases the brakes again so I'm not riding them.
 
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