Toad braking system with MH that has transmission retarder.

[RAnder35]

I am new to motorhomes and towing. Have a 1999 Foretravel which has a transmission retarder and air brakes. I don't have to touch the brake pedal very much except right at a stop sign. Is there a toad braking system that is compatable with this arrangement, if so which one. Thanks.

[Gary RVRoamer]

It all depends on when you want to have the toad brakes applied, either along with the retarder or only if the coach service brakes are also applied.
If your coach brake lights come on when the retarder engages, it is fairly simple to connect up any of the toad brakes that is normally triggered by the brake pedal switch and have the toad brake activated at the same time. However, most people prefer the opposite - no toad brake unless the coach brake pedal is pushed. That's easy to do too - just put a diode in the brake switch line after the point where the toad brake ties to the brake pedal, so that current cannot backflow from the coach stop lights.

If you use a system that is NOT tied into the coach brake light system, there is nothing to be done. I use a Brakemaster system with my DP with a two speed Jake Brake. The Brakemaster is totally air driven via a tap off the motorhome air brake lines, so it only activates when I push the brake pedal. That's fine by me. Most of the time the engine brake slows the coach & toad just fine without any assist from the coach and toad service brakes. When and if I need extra stopping power, I touch the pedal and get both coach and toad brakes, otherwise the engine brake alone is ideal. Saves on toad brake and tire wear and still gets the job done.

[David K]

I also have the Brake Master system and agree with the above post. My toad is a Ford Focus and does not weigh that much and only need to touch the brakes when coming to a complete stop.

[adamruss]

Since you have air brakes the best system by far is the SMI Air Force One. It works proportionally to how much your air brakes activate and that is all you need. If your toad brakes every time your transmission downshifts you are going to put alot of unnecessary wear on your brakes. the guy at Discount Towing Supply was able to explain this to me and give me alot of advice on towing.

[racer0624]

I've never had a trans. retarder but have been told by Foretravel friends that using it on long downhill runs causes the trans temp starts climbing. Extra weight of a toad could(?) make the problem worse???

[Gary RVRoamer]

Any aux brake system is going to cause engine heat to rise on a long downhill. Engine brake, exhaust brake or transmission retarder all do it. I've seen my Jacobs engine brake push it up 15+ degrees on a long, steep grade. The engine is working to help reduce speed, but not getting the much cooling flow from the radiator, so the temp climbs. If it starts to get too high or stays high too long, use the service brake more and the retarder (or whatever) less.

[Korryp]

Quote:

Originally Posted by adamruss Since you have air brakes the best system by far is the SMI Air Force One. It works proportionally to how much your air brakes activate and that is all you need. If your toad brakes every time your transmission downshifts you are going to put alot of unnecessary wear on your brakes. the guy at Discount Towing Supply was able to explain this to me and give me alot of advice on towing.

Replace SMI Air Force One with BrakeMaster. I've had the Brakemaster system in two MH's and wouldn't be without it.

[wa8yxm]

First with any system be it a Diesel with engine retard or trans retard or a Gasser with an Allison and grade brake.... Monitoring the trans temp. not a bad idea.

Second... Braking systems fall into 3 groups for this discussion

"Brake in a box" like Brake Buddy, Even Brake, And the like

This is a box you have to install every time you tow.. I seriously do NOT recommend them cause frankly I think they are too much hassle. however they sense when the car starts to slow down and apply the brakes.

If you are going down hill.. they apply the brakes.. EVERY TIME

Note a special case of this is the surge brake system like Ready Brake.. It too applies the brakes when it senses you trying to slow down the car. but it's way easier to hook up once installed.

The other systems are either air-systems powered by the Motor Home's air brakes and controlled 100% by the motor home's air-brake controller (save in a break-a-way condition but we won't bother with that here)

And electronic systems

The air brake systems work with the motor home's air brakes.. I DO recommend these systems where possible.. They are very good. Use of engine braking however will not activate them

Electronic systems such as the US-Gear Unified Brake Decelerator (Only, in my not very humble opinion, the best braking system for toweds) sense the brake switch.. If the brake lights are ON, the system is ON.

NOTE: I drive a gasser.. This affects my statment in prens above.

But I have to say the system has seriously impressed me under very nasty conditions.

[powerboatr]

Quote:

Originally Posted by RV Roamer [Gary] Any aux brake system is going to cause engine heat to rise on a long downhill. Engine brake, exhaust brake or transmission retarder all do it. I've seen my Jacobs engine brake push it up 15+ degrees on a long, steep grade. The engine is working to help reduce speed, but not getting the much cooling flow from the radiator, so the temp climbs. If it starts to get too high or stays high too long, use the service brake more and the retarder (or whatever) less.

mine is jsut the opposite
if i use the engine exhaust retarder and let the tranny do its thing the temps go way down. i can hear my engine fan engaged during this as well....

i am still trying to see if the brake lights come on with the engine brake engaging

[adamruss]

Quote:

Originally Posted by Korryp Replace SMI Air Force One with BrakeMaster. I've had the Brakemaster system in two MH's and wouldn't be without it.

I'm sure that system works for you but I feel much safer with a system that I don't have to take in and out of the toad every time I want to go on down the road. Also, the AFO energizes the power brakes on the toad so the brake pedal doesn't have to be pushed on at tremendous forces, as I understand the Brakemaster does. I talked with many people before I purchased my system and the overwhelming majority of them told me that I should get the AFO, even the people that had other braking systems.

[Techie]

We have & love the US Gear system. It ties into your brake switch so will not come on unless you press on the brake pedal.

[Korryp]

Quote:

Originally Posted by adamruss I'm sure that system works for you but I feel much safer with a system that I don't have to take in and out of the toad every time I want to go on down the road. Also, the AFO energizes the power brakes on the toad so the brake pedal doesn't have to be pushed on at tremendous forces, as I understand the Brakemaster does. I talked with many people before I purchased my system and the overwhelming majority of them told me that I should get the AFO, even the people that had other braking systems.

Takes me roughly 4 minutes to set up my Hybrid Escape for towing and probably 3 minutes to remove. Not sure where you heard that the Brakemaster takes tremendous force to press on the pedal since the brakemaster also energizes the brakes. Seems out west here with all the hills and mountains that the brakemaster is the choice of most RV'ers I see while traveling.

[Route 66]

Folks, we're getting off topic here.

The OP is looking for info on the Allison trans retarder interaction with supplemental braking systems.

Thanks!

[Pusherman]

OK, trying to get back 'on topic', for us folks who have engine retarders, you want to use them to their fullest capability when going down long grades. I would rather have my engine temp raise a few degrees than smoke my service brakes...

Regarding, toad brakes, I believe the collective wisdom is that you do not want them to engage going down a grade with the engine brake. You only want them to engage when you use the coach service brakes.

The coach is almost always capable of stopping your toad under normal braking. You only want toad braking during quick or panic stop situations.

If you have a 'brake in a box' system, set it for the lowest sensitivity. If you have a system which ties into your air brakes, then the system will do what it's designed to do w/o overly taxing the toad brakes. They work well.