Community Forums

Tom222 · 03-10-2014, 08:27 PM

What does the "retarder" with do, on the Providence 40X DP?

Thanks

Tom

I really don't understand why the manual does not explain things more.

Peterd503 · 03-10-2014, 08:48 PM

The retarder(common on allison trannies) absorbs energy to be dissipated as heat to provide braking action. It is a fairly efficient method of braking.

Tom222 · 03-10-2014, 09:36 PM

Quote:

Originally Posted by Peterd503

The retarder(common on allison trannies) absorbs energy to be dissipated as heat to provide braking action. It is a fairly efficient method of braking.

How do I use it?

CampDaven · 03-10-2014, 09:50 PM

Quote:

Originally Posted by Tom222

How do I use it?

Used a lot on downgrades to prevent excess wear on regular brakes. It downshifts the tranny and decreases speed.

Go down a steep grade. Press it.

flaggship1 · 03-10-2014, 09:54 PM

Someone on real computer - isn't there a sticky on Air Brakes - Retarders - Jakes etc. Can't get to it easily on my iPhone - but pretty sure there is one.... Can anybody link to it?

Muddypaws · 03-10-2014, 10:06 PM

There's more to it than just transmission downshifting. The attached picture is a PAC-Brake commonly used on Cummins & Cat diesels.

Google 'diesel engine brake' and you'll find about 10,000 explanations.

I leave mine on almost all the time and let the computer decide when to engage it. Especially in hills or traffic!

flaggship1 · 03-10-2014, 10:24 PM

I can't find the sticky - but if your like me - you have an Allison 3000 with Retarder. It works like this ---

http://m.youtube.com/watch?v=v4AJ2BvUMG4

But you may have more - as Muddypaws says.

There are lots of threads that explain the down shifting of the retarding to 4th gear and customizing the operation of the system. Put as Campdaven says - when your starting down a hill, giver flip er on. Or even driving on flatland - giver he a flip - and you'll feel the difference.

corprimo · 03-11-2014, 12:43 AM

We use retarders on the 45 foot tour buses I drive in AK - they work well but do generate heat, so watch your transmission temperature on long descents.

coolhand108 · 03-11-2014, 06:09 AM

I leave mine on constantly except when in ice or snow. lift the accelerator and it kicks in by itself. depress accelerator and it shuts off. drove truck for forty years with a three stage jake and never had a problem even in the winter, take it for what it is worth

John S. · 03-11-2014, 06:19 AM

I use mine all the time except in snow and ice. It is wired into my brake pedal and I have a joystick as well. Learn where the trans temp is taken. In the sump no more than 250 in the retarder it can go to 300.

Tom222 · 03-11-2014, 08:28 AM

Quote:

Originally Posted by coolhand108

I leave mine on constantly except when in ice or snow. lift the accelerator and it kicks in by itself. depress accelerator and it shuts off. drove truck for forty years with a three stage jake and never had a problem even in the winter, take it for what it is worth

Doesnt leaving it on decrease your mpg of the Diesel Engine?

John S. · 03-11-2014, 09:23 AM

We are talking a retarder. It only activates when I push the brake or pull the joystick.

This might explain it.

Transmission Retarder Operation - How Does It Work

corprimo · 03-11-2014, 10:46 PM

My understanding is that the three types of auxiliary braking are completely different from each other - exhaust brake (PacBrake is an example) creates engine compression braking by blocking the exhaust, Jake brake (Jacobson) creates engine compression braking within the engine itself (I'm not familiar with these), Retarder creates drag inside the transmission.

Smitty77 · 03-11-2014, 10:57 PM

I sure could be wrong, but suspect that your coach does not have a transmission retarded. Labeled that way, and it is a retarded of speed, but probably a exhaust brake.

What engine, as that would probably help confirm Exhaust vs Compression brake assist.

Best,
Smitty