Owner of 1981 F250 351W mileage 230,000.

Does anyone know exactly what the common failure is, when: applying the braking system in a 1981 F250 with a 351W - why does the engine stall when braking?

This has only happened twice, but it has scared the out of me.

The result is a loss of vacuum - to the vacuum booster - increasing the trucks braking time and distance necessary to come to a full stop.
In other words, (1) going through a stop sign, and (2) almost rearending a vehical stopped in front of me.

Recommendations that I have received are to (1) perform a fuel induction service, or (2)diagnos the carburater via a complete cleaning. I don't think that either one of these methods will find a solution.

How can I prevent this from ever happening again.


Please help!

Tom

 

[updated:LAST EDITED ON 09-Apr-02 AT 11:39 PM (EST)]I would start there due to how much that affects vacuum pressure in the motor which runs the booster as you know I would also check the intake manifold make saure all bolts are torqued down and all make sure no leaks and all looks good.
also forgot to mention check the rest of your vacuum lines make sure there in good shape and not dry rotted and all

Godbless you
Quads

 

I have an '86 F150 I6 300 automatic with the same problem (almost stalling while applying the brakes). With mine...the booster itself has a leak. The leak is inside the cab at the seal where the pedal meets the booster on the other side of the firewall. I found by spraying carb cleaner all around the area behind the brake pedal and sure enough, the idle increased.

So im gonna put in a new booster in about a week or so. I'll let you know how it turns out...GOOD LUCK

-Jack

 

Thanks Jack

I am getting the impression that everything plastic or rubber should be replaced that has anything to do with the F250's vaccuum.

Thanks

Tom

 

Didn't even think of the manifold. If that might be the case, could a leak in the catelitic converter or muffler create a leak in the vaccuum.

Thanks Quad

Tom