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-   -   Retarder switch? (https://www.irv2.com/forums/f258/retarder-switch-195863.html)

Tom222 03-10-2014 08:27 PM

Retarder switch?
 
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 (Post 1962703)
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 (Post 1962748)
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

Manuals
 
1 Attachment(s)
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 ---
https://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

Retarder
 
Quote:

Originally Posted by coolhand108 (Post 1962973)
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


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