Red knob next to the parking brake lever

[bbeenn88]

HI,

Since Ive got my bus I didnt know what this red knob is next to the parking brake lever. Just the other day I was looking at it with more detail because I was trying to fix the brake line but the warning lights are still on. (all three of them being: Brake system warning light, Brake electric motor warning light, and parking brake warning light)
So I decided push and pull on this knob and it pulls out and makes the engine idle higher. When you push back in the engine idles normally.
Unfortunately the website wont allow me to upload a photo at this time, I will try again later.

Can anybody tell me what this red knob does and is it a part of the braking system?

[Scooternj]

Sounds like its the high idle for the engine.

As for pictures- if you can't upload, host them on a third party site, like Facebook, Photobucket, etc., and paste the url of the picture with the img tag.

[bbeenn88]

The link for the photo of the knob and lever


http://i936.photobucket.com/albums/ad20 ... hoto47.jpg

[bbeenn88]

Heres a photo of the warning lights. All three are usually on but the Brake E motor and Parking brake lights randomly flicker.



http://i936.photobucket.com/albums/ad20 ... hoto48.jpg

[Scooternj]

Originally Posted by bbeenn88

The link for the photo of the knob and lever

That looks like a high idle with friction lock.

Originally Posted by bbeenn88

Heres a photo of the warning lights. All three are usually on but the Brake E motor and Parking brake lights randomly flicker.

As for the flickering lights? Could be a short somewhere. Maybe one of the Ford guys on here might have a better answer.

[bbeenn88]

Originally Posted by Scooternj

That looks like a high idle with friction lock.

As for the flickering lights? Could be a short somewhere. Maybe one of the Ford guys on here might have a better answer.

What would a high idle be used for? and when should you use it?

[Scooternj]

Originally Posted by bbeenn88

What would a high idle be used for? and when should you use it?

High idle is used to get the RPMs up for warm up in cold weather as well as getting air back into the airbrakes when its been bled out.

[nat_ster]

You have lucas girling hydroboost juice brakes. Parking brake is the lever to the right of the high idle thing you asked about.

Some engines will never warm up at a low idle. Also low oil pressure from low idle speeds can cause engine damage from lack of lubrication.

Modern computer controlled engines do this automatically.

Nat

[bbeenn88]

Thank you scooter and nat.


I think I only have one more question. The brakes I have are hydrolic not air, to make that hydro boost work correctly do I need to pull the knob out to get the correct pressure before applying the park brake?

Previously to finding out that that knob actually did something, I was not raising the RPMs to apply the park brake. All I was doing was pushing the brake pedal and switching the lever and I would feel pressure in the brake pedal as if the park brake was engaged.

[Redbear]

It looks like the same knob and cable used to adjust the gas/air mixture at altitude in a piston aircraft. If you twist the black knob surrounding the button, you should be able to make fine adjustments to the setting. Pushing the red button unlocks the vernier and lets you make major changes by pushing or pulling on the knob.

These controls have been used by others as a poor man's cruise control, holding the pedal to the metal on long stretches of interstate highway. It would especially be desirable with engines like a DT360 that barely maintains speed (if it can) at full throttle. Anyone trying this trick has got to train their mind to remember to smash the red button to the dash in a panic stop, as the engine is not going to drop to idle when you touch the brakes like a cruise control disengaging would.

I can't help you with the brakes.