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Wayne, Journeyman
Category: Heavy Equipment
Satisfied Customers: 8277
Experience:  34 years experiance as engine rebuild and problems.Thermo-King repair and trouble shooting.
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2001 International 4700 T444E Hydraulic brakes. When stopped

Resolved Question:

2001 International 4700 T444E Hydraulic brakes. When stopped and holding the brake pedal down after about 30 seconds the brake pressure light will come on and not go off unless the engine is shut down and restarted. Occasionally the light will come on while cruising down the highway. Again an engine stop and restart is required to turn off the warning. The pedal is holding fine and I have no problem stopping. Any ideas would be greatly appreciated.
Submitted: 6 years ago.
Category: Heavy Equipment
Expert:  Wayne replied 6 years ago.
Hi I'm Wayne,
I will try to help you with this,
I would start by checking the vacuum pump, on the fire wall, Driver side, all connections,
But I think you are going to find that the pump is bad, and gets re energized when with key off, and restart. You will still have a good brake, reason being, tank is holding vacuum, next time this does this, pull over and pump brake, and see if pedal gets soft.

Get back to me. Cool
Customer: replied 6 years ago.
I won't be in the truck again until tomorrow. I will give you more info tomorrow afternoon.

[email protected]
Expert:  Wayne replied 6 years ago.
OK, Hank,

Thank You

Customer: replied 6 years ago.
When using the brakes the pedal travels about a third of the way and is solid. Pumping the brakes seems to have no effect pedal stays solid same travel length. I also detected the sound of air escaping. Is the vacuum pump the round item under the master cylinder? If so the only connection I could see was the electrical on the top and the two bolts connecting it to the Master cylinder. enclosing photo.

Expert:  Wayne replied 6 years ago.

Yes the round item under the master cyl. is the pump, ,,But something That I have over looked, now that you sent a picture, replace that switch on the side of the master cyl. and the switch that connects to that rubber hose before you do any thing else.

Thanks, Wayne Cool

PS, Great picture, picture is worth a thousand words

Edited by wayne on 1/21/2010 at 4:28 PM EST
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