Author Topic: I.C.C confusion  (Read 3202 times)

Offline Darkspeed

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I.C.C confusion
« on: December 27, 2012, 05:36:53 PM »
In my x-6114 gm coach maintenance manual there are two valves described.

1. Page 17 - "Two way control valve (Also I.C.C. Valve)" that limits pressure to the front brakes on slippery roads.

2. Page 19 - "Auxiliary brake control valve (I.C.C.)" that isolates the pedal and aux tank and fully loads the rear brakes

In reading a lot of posts people seem to call both of these valves the I.C.C. valve.

Am I correct in these being two different valves, maybe that look the same?

If so was one or both an option on some buses?

I have one unlabeled flip valve on the drivers side wall - i have not traced it out yet.
4106 6V92TA MUI + V730 8" Lowered Floor & Polished > http://www.busconversions.com/bbs/index.php?topic=24673.0 QuietBox > http://www.busconversions.com/bbs/index.php?topic=29946.0
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Offline Sam 4106

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Re: I.C.C confusion
« Reply #1 on: December 27, 2012, 05:52:11 PM »
On the 4106 that we had, the rear brakes were applied whenever the fast idle was engaged. I wonder if that is the function of the valve on page 19.

Good luck, Sam
1976 MCI-8TA with 8V92 DDEC II and Allison HT740

Offline RJ

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Re: I.C.C confusion
« Reply #2 on: December 27, 2012, 05:55:11 PM »
Todd -

The rarely ordered optional front brake limiting valve was sometimes mounted on the floor, right in front of the driver's seat.  Driver could flip it on/off with his heel.

The other ICC valve was originally mounted in the console to the driver's right, along with the PA mic and amplifier.  This valve was standard on all coaches.  Some drivers found out the hard way that it was NOT a parking brake, because if you shut down the coach and left it with this valve "on," as soon as the air pressure dropped, the bus would roll. . . (unless parked in gear or with the Johnson bar on.)

Both valves were a flip-style design.

It would be my guess that the one on the driver's wall has been relocated from the driver's console, if that has been removed.

Sam -

Wasn't your coach set up such that the fast idle wouldn't come on unless the parking brake was set?  Your MCI is probably set up that way also?

FWIW & HTH. . .

 ;)
« Last Edit: December 27, 2012, 05:57:43 PM by RJ »
RJ Long
PD4106-2784: Donated to the Pacific Bus Museum
S14947: 1980 MC-5C Shell 6V92/HT-740
S13406: 1978 MC-5C Angola Coach - Swapped for vvv
M1001907: 1992 Prevost XL Vantarè Conversion 8V92T/HT-755 (DDEC/ATEC)
Cheney WA

Offline Darkspeed

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Re: I.C.C confusion
« Reply #3 on: December 27, 2012, 07:02:48 PM »
Thanks RJ! Thats what i needed to know.

Im guessing it got relocated.
4106 6V92TA MUI + V730 8" Lowered Floor & Polished > http://www.busconversions.com/bbs/index.php?topic=24673.0 QuietBox > http://www.busconversions.com/bbs/index.php?topic=29946.0
It's all math and metal...

Offline Sam 4106

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Re: I.C.C confusion
« Reply #4 on: December 28, 2012, 08:13:53 AM »
RJ, you are probably right in both cases. It has been over 3 1/2 years since we sold our 4106 and the memory fades with time. I have never tried engaging the fast idle on our MC 8 without the parking brake set. But, with the DDEC II, I am not sure the PO wired the interlock into the fast idle. Some day I will check that if I remember that long.

Thanks for the info, Sam
1976 MCI-8TA with 8V92 DDEC II and Allison HT740

Offline Lin

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Re: I.C.C confusion
« Reply #5 on: December 29, 2012, 04:32:52 PM »
The Jakes ate our fast idle, but when we had it, it would only work with the parking brake engaged.  I believe that was standard setup.
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