PD4106 Throttle Cable - Can't get it back in

[richard5933]

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?

[Geoff]

Using an angle grinder, zap the end of the cable to a fine point and try again.

[Melbo]

wrap it in tape before the angle grinder -- I usually use a dremel cut off wheel rather than an angle grinder.

Melbo

[eagle19952]

where'd you find a new PD-4106 ? 

[Utahclaimjumper]

Slowly spin it as you insert it.>>>Dan

[lostagain]

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

[Utahclaimjumper]

 Are you hitting the copper "bump" between the firewall and governor,??>>>Dan It can be removed and threaded independantly.>>>Dan

[richard5933]

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

[dtcerrato]

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

[chessie4905]

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.

[dtcerrato]

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.

[Geoff]

Isn't this the time to install an air throttle? It works great with an Allison auto transmission.

--Geoff

[uncle ned]

AM Geoff

And he will never regret it

uncle ned

[richard5933]

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.

[buswarrior]

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