Author Topic: Sticky gas pedal  (Read 1354 times)

Offline birdarchitect26

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Sticky gas pedal
« on: April 12, 2018, 06:50:58 AM »
I've now learned the hard way that my pedal sticks at about half - 3/4 depression. Under no load that's basically WOT; so not very exciting. The cable seems to actuate fine when released from the grease bar under the tire comp. I think something internal to the grease sleeve is causing this, like just a worn spot from highway driving. Where can i find a new linkage setup or any suggestions on how to repair this?

J
1973 MC7 Challeger
8V92Ta MCI conversion

Offline buswarrior

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  • '75 MC8 8V71 HT740
Re: Sticky gas pedal
« Reply #1 on: April 12, 2018, 07:12:01 AM »
Stock linkage?

Like a religion, there are numerous cranks, pivots and sleeves...

You MUST find the lube fitting at each and every point of movement between your big toe and the engine governor, some 38 feet back there.

A partner to manipulate the throttle while you pump grease into each fitting to get it moving...

Pay wicked attention to where the rod enters and exits the tunnel, the hardest to see and reach, these were skipped by the paid help in the coach's previous working life, and by a lazy/ignorant previous owner.

Do not condemn the system, or make this more complicated until you get it greased and freed up.

Happy coaching!
Buswarrior
Frozen North, Greater Toronto Area

Offline lvmci

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Re: Sticky gas pedal
« Reply #2 on: April 12, 2018, 08:23:47 AM »
Hi J, I just went thru this 2 weeks ago, pedal was sticking on deacceleration, on my 102C3, the cable was starting to fray, lubing did help that, but the custom end piece from MCI, which has a special shape screw bolt as part of the end connector to engine, was cracking and bending, which would have completely disconnected accelerator pedal from engine, lvmci...
MCI 102C3 8V92, Allison HT740
Formally MCI5A 8V71 Allison MT643

Offline Bill Gerrie

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Re: Sticky gas pedal
« Reply #3 on: April 12, 2018, 10:06:29 AM »
You could change to an air throttle and no further problems. I know where there is one for a decent price.

Offline birdarchitect26

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Re: Sticky gas pedal
« Reply #4 on: April 16, 2018, 09:15:54 AM »
Thnaks guys,

I'm leaning toward and air throttle, but I'm sure its not in my budget ATM. But feel free to shoot me some details.

I'll crawl under there and try to find any additional grease fittings, I thought I got them all but maybe I'm missing one. I plan to figure this out this week, so I can safely make an upcoming trip.

Jay
1973 MC7 Challeger
8V92Ta MCI conversion

Offline DoubleEagle

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Re: Sticky gas pedal
« Reply #5 on: April 16, 2018, 11:34:11 AM »
A stiffer return spring might help if lubing does not, but then your foot will long for an air throttle.
Walter
Dayton, Ohio
1975 Silvereagle Model 05, 8V71, 4 speed Spicer
1982 Eagle Model 10, 6V92, 5 speed Spicer
1984 Eagle Model 10, 6V92 w/Jacobs, Allison HT740

Offline richard5933

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Re: Sticky gas pedal
« Reply #6 on: April 16, 2018, 01:38:55 PM »
Just be careful if you decide to pull the cable out. I had a sticking throttle and pulled out the cable to clean/lubricate it. When I went to put it back in i hit a dead-end about 1/3 of the way in. Ended up that there was a fracture in the tube, and the ends of the broken tube were rubbing against the cable making it stick. When I pulled it all the way out, the broken ends of the tube collapsed into the tube, which kept the cable from going back in. Had to replace a few inches of the tube, then all was good.

If you can gain access to the tube housing the cable it would be a good idea to evaluate to be sure that it's intact. Also take a look to be sure that no screws (from flooring or furniture above, etc.) have penetrated the cable tube.
Richard
1974 GMC P8M4108a-125 (Current Bus)
1964 GM PD4106-2412 (Former Bus)
Located in beautiful Wisconsin
KD9GRB

Offline birdarchitect26

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Re: Sticky gas pedal
« Reply #7 on: April 16, 2018, 02:50:14 PM »
I contorted under the spare tire comp after work, made sure it had grease spewing, same problem. Unhooked the cable from the actuation arm, the arm moves great, all greased up.

The cable is hard to travel and must be the problem, I'm scared to go through the process, is the cable inside another tube? Like cable with sheathing inside a conduit-like tube? I'm guessing the only access is either from front or back of the bus?

The front is grey in color, the back is red until the firewall.


1973 MC7 Challeger
8V92Ta MCI conversion

Offline lvmci

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Re: Sticky gas pedal
« Reply #8 on: April 16, 2018, 04:40:03 PM »
Hi, yes it's a hard plastic tube, similar to pex tubing, with aircraft style cable inside, runs over 38' front to back. They pulled the old one out, but attached the new one on the end and pulled it thru. MCI still had my accelerator cable, lvmci...
MCI 102C3 8V92, Allison HT740
Formally MCI5A 8V71 Allison MT643

Offline Bill Gerrie

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Re: Sticky gas pedal
« Reply #9 on: April 16, 2018, 06:58:21 PM »
If you want an air throttle I know of one for $250 complete plus shipping. You can email me at retiredbusnut@yahoo.com if you want.
« Last Edit: April 16, 2018, 06:59:54 PM by Bill Gerrie »

Offline birdarchitect26

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Re: Sticky gas pedal
« Reply #10 on: April 17, 2018, 04:31:43 AM »
I'm going to assume the ending portion, aka the red tube in the rear must be the tube that runs the length of the bus.

Bill, I sent you an email, hopefully I can transition to a new style, I'll be sure to update with my experience and pictures. I have to imagine my right quad will at least thank me.

J

1973 MC7 Challeger
8V92Ta MCI conversion

Offline lvmci

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Re: Sticky gas pedal
« Reply #11 on: April 17, 2018, 06:44:20 AM »
Hi, tried to put picture here of the specialty connector, that connects to the engine side, will put it on MCI busconversions on face book, lvmci...
MCI 102C3 8V92, Allison HT740
Formally MCI5A 8V71 Allison MT643

Offline birdarchitect26

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Re: Sticky gas pedal
« Reply #12 on: April 19, 2018, 08:59:37 AM »
Well I still sit with my problem of a malfunctioning cable. Is there a place I can source an air throttle to fix the bus? Does anyone else have an extra air throttle or know of one for sale? I suppose I will also take someone up on a new cable suggestion. I can't seem to find anything close to that length. Its now starting to get warm here and I sure would like to move our home around to sight see.

Thanks,
Jay
1973 MC7 Challeger
8V92Ta MCI conversion

Offline richard5933

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Re: Sticky gas pedal
« Reply #13 on: April 19, 2018, 10:48:40 AM »
What diagnostics have you done so far? Any clue where/what the problem is with the cable?
Richard
1974 GMC P8M4108a-125 (Current Bus)
1964 GM PD4106-2412 (Former Bus)
Located in beautiful Wisconsin
KD9GRB

Offline Bill Gerrie

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Re: Sticky gas pedal
« Reply #14 on: April 19, 2018, 07:39:48 PM »
Jay
I sent you an email about a new one. Call Luke at 1-888-262-2434. He has access a new one. Sorry about the other.