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Topic: throttle swap to air throttle (Read 1037 times) previous topic - next topic

throttle swap to air throttle

Hi All,
Had a breakdown last weekend and result may be that I have to swap out the old Cruise King throttle set up to an air type throttle set up because Cruise King is no longer in business. Can anyone relay what is involved and how you did the swap over?
At mechanic's now and would like to fill him in on possible solutions id the old unit can not be fixed.
Thanks, Windwalker
2002 Custom No Slide U320
98 U295 36'
92 Grand Villa 29' front engine gas-Sold
Motorcade 18100

Re: throttle swap to air throttle

Reply #1 –
Quote from: windwalker –
Hi All,
Had a breakdown last weekend and result may be that I have to swap out the old Cruise King throttle set up to an air type throttle set up because Cruise King is no longer in business. Can anyone relay what is involved and how you did the swap over?
At mechanic's now and would like to fill him in on possible solutions id the old unit can not be fixed.
Thanks, Windwalker

Let's all hope that your Cruise King can be repaired.  However, I have given some thought to what will I do when my Bendix system has a failure.  There is a company with an off the shelf - universal solution for the classic Wanderlodge and Bus conversion people.
In my case I pretended nothing will ever go wrong with the foot feed air valve and convinced myself that I can source a standard air cylinder and have a custom cable made to fit the air cylinder to control the injector rack.

So if you still have your original air valve, you're halfway home.  But other than ordering the parts for the aftermarket air throttle I wouldn't trust my mechanic to source the solution.  Unless I felt like funding his education.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: throttle swap to air throttle

Reply #2 –
A not uncommon conversion.

Suspect someone who has done it/had it done will have specifics.

If not, I am sure Foretravel or MOT is familiar with the conversion.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: throttle swap to air throttle

Reply #3 –
Is the throttle control on the 1998 model not electronic?  I assumed all '98 models would use electronic throttles.

King Control Throttle and Cruise Control Issues

We have had Forum members go from air throttle (Bendix system) to Cruise King, but I don't recall anyone going the other way (electric throttle to air operated throttle).

The air throttle on my '93 model consists of two basic components:  a master control valve (accelerator pedal) and a slave cylinder, connected by a air hose.  See diagram below.

I am guessing, on your newer '98 model, that your accelerator pedal is just a potentiometer, connected by wires to the Cruise King module?

If I am wrong, someone will slap me up the back of my head (Gibbs Slap).

If I am correct, I think converting your electronic system to air throttle would probably be expensive (parts + shop time).

Better to try to find a different electrical engine throttle system that would interface with your present pedal setup.

Sorry, I have no info on where you would find such a product.  GOOGLE is your friend!
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: throttle swap to air throttle

Reply #4 –
If the cable travel is long enough this would replace the Bendix cylinder and cable.  But you would still need the foot feed valve.
CONRADER Cable Throttle Control - 12U311|TCLP-36 - Grainger


The front door to air throttle parts:
Williams Controls | Curtiss-Wright

And after the click through:
Pneumatic Controls | Curtiss-Wright

There are commercially available solutions.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: throttle swap to air throttle

Reply #5 –
Windwalker,

In the middle of a long thread about "low engine power" problem, I found this post identifying 2 electric switches that are critical to operation of King system.  If your problem is "low power" as opposed to "no power", you might have mechanic check them out.

Low Power From Engine
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: throttle swap to air throttle

Reply #6 –
Indeed several different systems were used over the years.

Since the OP has King Control throttle and cruise, discussions of the also widely used Bendix system are probably not relevant.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: throttle swap to air throttle

Reply #7 –
Hi All,
Thanks for the responses, just to clarify
I have an electrical type Cruise King controller, I do not have an air controller.
From what I have heard the Cruise King controller is outdated tech and is no longer in business. If it can not be repaired it looks like I will have to either try to find another electrical type system or convert to an air controller.
I guess firstly is there a direct swap out available for the Cruise King, if not what is needed to swap to the air system?
Condition now is the engine runs fine and when I twist the throttle connection on the side of the engine it revs fine. The foot pedal in the drivers area does not rev at all, so there is some issue between the foot pedal, wiring, or Cruise King controller.
2002 Custom No Slide U320
98 U295 36'
92 Grand Villa 29' front engine gas-Sold
Motorcade 18100

Re: throttle swap to air throttle

Reply #8 –
Quote from: windwalker –
The foot pedal in the drivers area does not rev at all, so there is some issue between the foot pedal, wiring, or Cruise King controller.
Could be something very simple and cheap to fix.  Loose wire?  Bad ground.  Bad/dirty switches or contacts?

Have your mechanic follow the trouble shooting chart, and see what he finds:

NO THROTTLE, NO CRUISE, NO FAST IDLE
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"
 

Re: throttle swap to air throttle

Reply #9 –
Thanks for the troubleshooting chart...sent along to the mechanic
2002 Custom No Slide U320
98 U295 36'
92 Grand Villa 29' front engine gas-Sold
Motorcade 18100