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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: richard5933 on June 18, 2017, 01:41:19 PM

Title: PD4106 Throttle Cable - Can't get it back in
Post by: richard5933 on June 18, 2017, 01:41:19 PM
Had a very sticky throttle cable on our new PD 4106. Took out the cable to clean and lube. It came out pretty well, just a few more stuck areas than others but overall pulled through okay.

Cleaned. Lubed.

Now it only goes 16 feet from the back insertion point before it hits what appears to be a dead end. This would be at the bulkhead between two bays. The front of these two bays has the cover plate removed and the tube feels okay down the length. The back of these two bays contains the genset on one side and the water tanks on the other. The cover plate was left in place. No way possible to visually inspect or to get my hands on it from underneath.

Right now it seems to me that I've got a very big problem on my hands.

Any suggestions?
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: Geoff on June 18, 2017, 02:04:42 PM
Using an angle grinder, zap the end of the cable to a fine point and try again.
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: Melbo on June 18, 2017, 04:09:16 PM
wrap it in tape before the angle grinder -- I usually use a dremel cut off wheel rather than an angle grinder.

Melbo
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: eagle19952 on June 18, 2017, 04:24:22 PM
where'd you find a new PD-4106 ?  ;D
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: Utahclaimjumper on June 18, 2017, 04:32:00 PM
Slowly spin it as you insert it.>>>Dan
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: lostagain on June 18, 2017, 04:57:13 PM
You could try pushing a smaller cable through, and if successful, pull the throttle cable with it.

And or: inject some lube into the sheath first.

JC
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: Utahclaimjumper on June 18, 2017, 07:25:19 PM
 Are you hitting the copper "bump" between the firewall and governor,??>>>Dan It can be removed and threaded independantly.>>>Dan
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: richard5933 on June 18, 2017, 07:26:06 PM
First... New is such a relative term, eh? Guess I should have days 'new to me'

I followed the advice given and sharpened one end. Was able to get it through, but it's not right and sticks even worse. I have to operate barefoot at the moment to look pull the pedal up. Dangerous and not my style.

Here's the way this played out...

1. Test drove the bus a few weeks ago. Pedal was stiff and didn't really engage throttle until about a third of the way down.

2. On the drive home pedal got progressively stiffer, and about 30 minutes from home (after 4 hours on the road) I had to quickly 'blip' the pedal to get it to come up.

3. Got it home and thought it would help to remove, clean, lube, and reinstall the cable.

All went well until about 16 feet from the front when it felt like I hit a wall. I'm guessing that a split was forming in the tube which got progressively worse, until I removed the cable and the ends of the tube shifted causing the blockage.

Can't get anywhere near the problem area - hidden between a generator and my tanks. Can't get to it from above.

So, now I'm looking for other options. If there is a way to repair it blind that's great. If not, what options exist for air throttle or electronic? The tranny is auto Allison, so I'm assuming these are possible. Just two I don't know where to begin.

Any help would be great.

Sent from my SM-G935V using Tapatalk
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: dtcerrato on June 18, 2017, 07:49:39 PM
I would be inclined to spend more time on the conduit than on the cable. Get something smaller into the conduit (end to end) so you can start snaking back & forth.
Snaking as in small cylindrical wire brush with solvents to start with. It may not be a mechanical crush or failure of the conduit as much as a "build-up" that has accumulated and hardened - like plaque build up! Just saying. We remedied our 4104 cable at least a couple times in three decades starting with tight cable action & lack of response as you explain and ending with "holy crap that feels great" using the above method. IMO we recommend against oily lubricants. Dry lube is best - graphite just a pinch not a lot. Just before you think you've freed any obstruction in the conduit & before inserting the cable, flush with an evaporating solvent (like Brakekleen) & purge with compressed air until what exits is clear. My 2 cents
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: chessie4905 on June 18, 2017, 07:50:34 PM
If the throttle tubing curves in the engine compartment, look for wear through on side of curve; common problem on the 4104's. Your 4106 may be similar.The tubing is made of brass. If that is your problem, you can replace bad section with brake line tubing of appropriate size and compression fittings.
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: dtcerrato on June 18, 2017, 07:56:26 PM
We're familiar with the turns you're talking about. The original tubing is steel. Copper is used sometimes as a replacement but wears really fast.
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: Geoff on June 19, 2017, 06:30:42 PM
Isn't this the time to install an air throttle? It works great with an Allison auto transmission.

--Geoff
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: uncle ned on June 19, 2017, 06:32:33 PM


AM Geoff

And he will never regret it

uncle ned
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: richard5933 on June 19, 2017, 06:36:05 PM
That was my thought. Is there just the one source for the air throttle kit from Coach Conversion Central?

I took the coach to Interstate here in Milwaukee. There were a few other items to address, and I thought that they'd be best able to get the current setup in working order. If not, then air throttle is my next option (I think).

Fun drive to Interstate - had to drive barefoot so that I could fully pull up the pedal at a stop. I'll be glad to have this fixed, as it gives me shivers just thinking about it.
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: buswarrior on June 19, 2017, 10:36:45 PM
put some diesel through the cable sheathing.

pour it in and send it through with a LITTLE air pressure.

Prepare properly to minimize the mess.

Follow with the good lube and the cable

happy coaching!
buswarrior
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: dtcerrato on June 22, 2017, 06:35:26 PM
Richard, how did you make out with your 4106 throttle cable?

Does anyone know where I can get a 4104 throttle cable?
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: richard5933 on June 23, 2017, 04:04:09 AM
I got it to work well enough that I could drive to the local Interstate repair shop. Had to keep my shoe off so that I could pull the pedal back up with my toes though.

I have a few other issues that I wanted them to look at (like my Jake brake not engaging) so it seemed best to me to just let them have a go at the throttle cable. I'll let you know how it turns out.
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: richard5933 on June 28, 2017, 04:56:45 PM
Brief update...

Seems the problem with the cable was bigger than I would ever have solved. The tech at Interstate put in quite a few hours to get it going. Last I spoke to them, one of the major problems was likely a screw which had worked itself through the cable tube. My guess is that someone used screws for the sub-floor which were too long and which poked down through the floor and near the cable tube. Over the years, the screw tip broke through the tube and caused interference.

The tech was able to separate a union joint in the tube near the screw. He ground the end of a long (12") screw to make a cutting edge, and then was able to 'roto-rooter' the blockage out. There were a few other problems he found with the cable, but I've not had a chance to get all the details.

Hopefully having a freely moving throttle cable will also help my Bendix cruise work better. Previously it took two tons of effort to depress the pedal, so the cruise should have a much easier time keeping up now.

So, lesson of the day is to be sure screws holding down the sub-floor are not too long.
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: chessie4905 on June 28, 2017, 07:30:12 PM
Nice to hear you have a tech working on it that can solve difficult issues with injunity instead of just throwing up their hands.
Title: Re: PD4106 Throttle Cable - Can't get it back in
Post by: dtcerrato on June 28, 2017, 08:19:58 PM
Nice find, glad it worked out, thanks for the update...
Title: Re: PD4106 Throttle Cable - Back on The Mend
Post by: richard5933 on June 29, 2017, 02:25:59 AM
Yeah - Overall I'm quite impressed with the guys at Interstate. I originally chose them after reading the Technomadia blog post they wrote about an engine rebuild. Their work was done at another Interstate location, but I hoped that the dedication to quality carried system wide. It does in Butler (Milwaukee) Wisconsin.

They are also working to piece together my gauges and a few other items. I'll report again when things are complete.
Title: Re: PD4106 Throttle Cable - Back on The Mend
Post by: B_K on June 29, 2017, 06:25:04 AM
Quote from: richard5933 on June 29, 2017, 02:25:59 AM
Yeah - Overall I'm quite impressed with the guys at Interstate. I originally chose them after reading the Technomadia blog post they wrote about an engine rebuild. Their work was done at another Interstate location, but I hoped that the dedication to quality carried system wide. It does in Butler (Milwaukee) Wisconsin.

They are also working to piece together my gauges and a few other items. I'll report again when things are complete.

I only hope that you'll still be able to AFFORD to report after they get done w/you!
:D  BK  :D