Disc Brake Conversion

[Stircrazy]

Originally Posted by aehjr

Yes, level of effort is set to high and trailer gain is set to 6. On our next trip, I'll try a higher setting on the road. In town, anything higher than 6 is too grabby on the trailer brakes.

Thanks,
Alden

wow, for my 5th I run them on 9, and I am the same weight and lenght as you. weird, but I like them so I feel the trailer brakes coming on , that way I know the truck isnt doing everything.

Steve

[ewbldavis]

Interestingly - my TT was 6.5.

The Cougar is 3.5! feels about same as TT.

[mossdavidh]

Performance charged us about 2100 for the complete job including all parts and labor. We are a heavy Montana at almost 17000 pounds. Lighter trailers are less expensive. Moryde will do 8000 pound dependent suspension and disc brakes for around 4500 at their factory. You can stay in the trailer with electric supplies.

[dooby]

Consider redline as the maximum engine rev while making power. Under braking conditions the engine is not making power and therefor not producing the heat that it would be under heavy load. Exhaust brake is there for you to use. It's a way to control the speed without producing parasitic friction in the braking system. Think of it as giving your truck a rest from climbing that 8% grade. That's where the wear and tear happens.

[cenders]

During the install of the disc brake system, could a line lock be installed which "locks" the brakes on (ie: prevents the brake fluid from releasing) thus eliminating the need for wheel chocks? That would be a super bonus in my mind.

[Mikelff]

I’m wondering why you think 3500 rpm is a high rpm? It’s not even 50% to the red line and as others have said, your engine break system will not let you over rev your engine. I don’t do much mountain or hilly travel so my drum breaks work well for my 40’ 5er. If you travel often in the mountains I can see where disc brakes would be worth the $$. Just depends on the geography you travel. I have traveled through the mountains and over Monarch pass and engine break and an occasional tap on the breaks was all that was needed. Too many people don’t know how to break in the mountains (pump them) and I’m alway smelling hot breaks, and they are not towing anything. I took my 5er down a 10% grade at just under the speed limit with no issues. Just have to know “how” to do it. Pump the brakes, don't stand on them. I turned up my electric brakes in the mountains by one or two settings and back to original setting once down. Your 5er/trailer is supposed to stop at the same rate as your truck, not pull on your truck. Safe travels!

[avalanchehd]

My 2012 duramax will push into the 4500 rpm range while on the exhaust brake. The computer want allow it to over-rev

[Rbpinney]

You don't have to go to an RV dealer for that service. Any place that sells and services trailers can do that for you and will probably charge much less. They are just trailer brakes.
I've had my 5th wheel bearings replace at Fox Ridge in Castle Rock, CO. Great guys to work with.

[lunge motorsport]

Greetings…


So… I always read with interest the threads about disc to drum conversions. The opinions vary like they do on everything. Prior to my conversion I did months of research. I looked at every piece of information I could find, from the forums to the blogs to the pro websites.


I am a building trades journeyman in the plumbing industry for the last 40 years and during those years I have spent time building race cars to compete as a successful amateur road racer. I mention this because I have spent my adult life turning wrenches and designing high performance braking systems for many different applications. This may or may not have any value to anyone but me but it does lend to a certain perspective other than the RV realm.


I have been towing trailers since the mid 80’s, race car and camping. My old Aljo was a 26’ travel trailer with a #7400 GVWR and my race car trailer is rated at #7500, my current rig is a Cougar rated at #10,300. All of these rigs came with electric drum brakes and all are towed with a ¾ ton truck and all within the rated limits. Current TV is a 2013 GMC 2500 HD with real brakes unlike my old ¾ ton Suburban with front disc brakes that were marginally sized at best. I have never hit anything while towing but I never put myself in a compromising situation, also I have been lucky that nothing has ever come up that required superior braking.


I purchased the Cougar new in 2015, it had #4400 axles and 12’’ electrically operated drums. In my opinion this is woefully undersized although the standard of the industry. After a trip through the Siskiyou Mtns in CA, I had had enough of this marginal electric braking system and decided on making the change. You can see the project in my posted albums and I also have a blog called “checkmybuild.com” that has very detailed info on the conversion so I won’t go into it here.


My results have been fantastic, there is no comparison between well designed hydraulic disc brakes and electric drum brakes. For those that say that drum brakes are adequate if maintained properly…adequate is just not good enough for me and I wish only the best for you. Done well the conversion is spendy. I purchased components that I believe would be the best option for me. Dexter #7000 Torflex axles with 13’’ ventilated rotors and 8) 9/16’’ studs, the rotors are Dexter 4 piston using a Dexter elec/hyd actuator. Yes, the parts are more expensive than kits offering passenger car single piston sliding calipers that are rated for the front wheel application on a #3000 automobile, but this system is rated for the load and not for replacement costs of pads.


There are performance considerations between the two systems though. Electricity travels at about 90% of the speed of light. This means that the brake magnets are energized nearly instantaneously and then the shoes begin to spread into the drums creating drag or braking force. It also means that the hydraulic pump which carries no residual pressure begins to pressurized the hydraulic lines and that pressure then begins to move the pistons in the calipers towards contact with the rotors creating drag or again, brake force. There is a delay with any elec/hydraulic disc brake set up. Note that there is slight pedal travel in your properly maintained automobile brakes.


Additionally, the more rubber brake hose that is incorporated in a hydraulic system the more performance lag there is due to hose growth under pressure. I have seen systems that use over 20’ of hose…ugh.


Finally, drum brakes do not shed temperature very well and heat build up can led to brake pad failure and loss of brake effectiveness. Disc brakes shed temperature much better than drums and that is the greatest advantage. Drum brakes (given equal brake swept area and a properly designed and maintained system) have greater initial stopping power due to the leverage effect of the shoe wedging itself into the drum. The disc is just squeezed by the pads offering no leverage effect at all. This is why drum hydraulic actuators are rated at about 1000 psi and disc actuators are rated around 1600 psi. Drums just don’t require more pressure for initial lock up, but then I just can’t imagine going to all the work to install a hydraulic system just to provide drum brakes with hydraulic actuating.
The bottom line is the brake force performance gains and the relative lack of maintenance on a disc system far outweigh the lag time it takes for the initial grab to begin. While electric drum brakes will actuate slightly quicker, some systems will not provide enough brake force to lock the wheels on a heavy trailer. This is usually due to undersized wire and poor connections (wire nuts)! Disc brakes with light gauge wire will underperform as well.
A pretty wordy opinion but it is my experience, you get to do what you want and I’m just offering this for your consideration.


The above text was posted quite a while ago on this forum and I would now like to add a few more comments…


Prior to making these added comments I walked out to my trailer to get a look at the abandoned coil of SAE listed 14/2 brake wire that was used in my coach prior to my disc brake conversion. I mention this as wire sizing has a strong influence on electric brake performance. Additional considerations would be the wire connections provided by the tow vehicle and coach manufacturer. My coach under sized umbilical cable from the 7 pin connection was terminated in a residential concealed 4 square box that is not designed for outdoor use but is exposed to the elements as it’s mounted under the pin box. Then the coach’s 14/2 brake cable was attached to the umbilical cable using wire nuts! Now if all things are well designed and executed (which they typically aren’t in a mass produced coach), then you may achieve satisfactory performance from an electric drum brake system, until superior braking is required.


Now to address the comments I have read from other posters here…


The idea or justification for not doing a disc brake conversion based on the amount of time/miles that you spend in your coach seems ludicrous to me. Brakes aren’t just cheap insurance they are pre insurance. Having great brakes “may” save you from an event that will require the phone call to your insurance or health provider. I also don’t believe that using parts spec’d for a 3,000 lb automobile are sufficient for a 10,000 lb coach. I do however believe that they are probably better than electric drums under most towing situations if the installation is well executed. The problem is that many of the installations I have seen posted use small caliper/pad combinations, don’t address the small wire gauge from the tow vehicle to the hydraulic actuator, and use far too much flexible brake hose.


I understand that after spending $30k plus for a coach and hitch, there may not be enough skrill left over to make this conversion, but it take just once for the electric drum brakes to fail or under perform for the owner/driver to realize the value of great brakes. Many will never require extraordinary performance from their trailer brakes, I consider those folks to be blessed. For me, I have based my conversion on the safety factor that real brakes provide and not the amount of time I spend on the road in my rig.


Good luck

[EMTPRescue]

I just logged in to look specifically at this blog. We have a new 2019 Montana 3790RD. Tow with a 2009 GMC 3500HD with a tricked out Dmax and an aftermarket electronic diesel exhaust brake. I ALWAYS tow in Tow Haul. In Tow Haul mode, the Allison shift points are changed. The down shift RPMs for engine braking are changed and most importantly but a little know fact is that the trans torque converter while in Tow Haul locks up in every gear except 1st. That keeps the slip down because torque converter slip equals increased tranny temps. On the subject of Tow Haul, I recommend ALWAYS using it while towing. I regards to RPM while down shifting, the Dmax has two red line RPM specs. One is while pulling or working the other (which is higher) is for engine braking. Two totally different loads on the power train. We live just on the eastern side of the Canadian Rockies. The braking capacity of this trailer has always concerned me. We went across the scales the past summer at just under 27K total weight. During normal non-panic type stopping the trailer is at best OK thanks in larger part to my engine brake and manually shifting the trans down while in Tow Haul. When we headed west this summer and transited through and on the numerous mountain passes that are the Trans-Canada Highway, it became evident that the braking ability of the trailer itself is woefully inadequate. I had two situations with one being an individual merging onto the highway pulling in front of me at far too low of a speed and the second where an individual who was passing a larger number of vehicles behind us went past only to realize that he had run out of room and had pull in front of me with little to no room to do so. In both cases I was required to get on the brakes hard in order not to collide with the offending vehicles. In both situations it was evident that I did not have enough braking capacity. No collision ensued but they were close enough calls that my wife thought that we were going to hit them in both situations. I should put this in context as well by stating that I am a front line Paramedic so driving evasively and having to brake hard to avoid hitting someone who, lets say for instance, just hammers the brakes in front my responding Ambulance is quite a common occurrence. In those situations they have the Stop part of the requirement down they just have to work on the Pull To The Right part. I do not drive our truck while towing over 100KPH (62MPH). I have always said that getting this stuff moving is the easy part but getting tit stopped is a must. I remain acutely aware of my driving environment so the clown who was passing me and the 5 other cars behind me did not take me by surprise. I knew he was not going to have the room he needed and I began to brake long before he was fully past us. In summation I would respectfully submit that these large and heavy units are very much "under braked". Those who say weigh the cost of upgrading against how often you tow in my mind is akin to saying that you don't really need insurance because you have never had a claim. If your RV is ever on the road and it is a large heavy unit like ours you need to consider spending the money. In reading this blog not one person has said that they felt they wasted their money. I will be upgrading ours based on those two very undesirable experiences this past summer. I would rather know for certain that if I have to conduct an emergency stop that I can get everything slowed or stopped before I hit something. I will continue to read this blog to get ideas from guys that have done the upgrade, which manufacturer they used and most importantly, what the tangible differences were that they experienced. I can do that work myself. Dexter makes a package but they also make the stock axles with the stock drum brakes so I am a little hesitant to use the same manufacture that has got me to point of needing the upgrade to begin with.

[notanlines]

Lunge and EMTP, allow me to take you both to task (no, you won’t be grounded or sent to bed without supper) in regards to the length of your posts. I realize we have a number of members (and a moderator or two) who get a little wordy at times, but both of you far exceeded the maximum that the average reader is willing to spend. I’m quite sure what you wrote was very informative, but most simply don’t have the interest in every little nuance of the situation. Maybe work at getting to the point, or putting past posts in italics so readers don’t have to wade through that again.
We are interested, but don’t have that much time.

[HDroadglide]

I have had two sets installed one on my 2013 Raptor and the other on 2020 Raptor toyhaulers. On a double axel trailer the total cost was $3100.00 that was parts and labor.

Like you I go out west every year mainly to Colo. and feel safer with the disk brakes.

Performance Braking Co.
Norman, Ok

[lunge motorsport]

Notan

I read posts on many forums and as an avid information absorber I appreciate a well written and informative post. I also have the ability to determine whether I will read an entire post or not without another member making that decision for me. So while you may tire of the read, another may not. Case in point... I did notice that the post following mine was wordy but, I found it interesting and read it in its entirety. More importantly, without feeling like I needed to take him to task...If you feel that a post is too much, by all means, pass it by, it’s called your discretion. I would like to keep mine.

[77cruiser]

I'm envious of someone that is willing to type that much & be able to put together a post that long & keep it informative.

[McRod]

Originally Posted by aehjr

I've been thinking about making the switch to disc brakes since we purchased the trailer. Every camping trip we make involves driving over a mountain pass in Colorado or other western states. Even driving down to town for trailer service includes a 2,000' drop in 10 miles and an 8% grade. On our last ride over Monarch Pass, I got stuck behind a car driving way under the speed limit; I was on the brakes the whole time because using Tow/ Haul mode had my engine screaming. Figured it was better to wear out the brakes than to blow the engine.

I've searched the forum to look at previous posts on the topic; my question is what should the parts cost and how many hours of labor should I expect the shop to charge me? I have an estimate from Windish for $5,000 with $3000 of that being the parts. They also quoted me four months for scheduling due to how many trailers they've sold this year and the number of rigs being serviced. I'm reasonably handy but have no interest in sitting in the cold and snow doing a brake installation so am happy to pay a shop to do the work.

Any recent experience with parts and labor costs would be appreciated.

Thanks,
Alden

The complete parts retail are about $1800. That includes EOH actuator and brake lines. Install included total is about $3k total.

[gearhead]

Looks like parts for double 8K axles is $2285.
Does anyone know what the labor charge is for having Performance Trailer Braking install the kit at their shop in Norman Oklahoma versus an authorized shop or mobile tech?

[moodman]

Since the guy was going so slow, couldn't you just pull over for 5 minutes and let him go on, then rejoin traffic later?

[travelin texans]

Their installers came to my site & charged $1000, I'd suspect it would be the same price in their shop. Much easier for me to of had them come to me.
The park we were in they did 4 others after mine in 3 days with an excellent job done on all of them. One of those had new axles with the disc & another had to have spring hangers welded with shackles & wet bolts, all done on their sites. Those installers know what they're doing.

[gearhead]

[QUOTE=moodman;418372]Since the guy was going so slow, couldn't you just pull over for 5 minutes and let him go on, then rejoin traffic later?[/QUOTe
Yeah probably the best.
But, I'd say I would just bump draft them.

[gearhead]

Originally Posted by travelin texans

Their installers came to my site & charged $1000, I'd suspect it would be the same price in their shop. Much easier for me to of had them come to me.
The park we were in they did 4 others after mine in 3 days with an excellent job done on all of them. One of those had new axles with the disc & another had to have spring hangers welded with shackles & wet bolts, all done on their sites. Those installers know what they're doing.

Yes it would be easier to do it in my driveway. If it was significantly cheaper I wouldn't mind going to Norman. Got kinfolks there that are overdue a visit.
I've got the question in to Performance Trailer Braking through their website.