My 94 F250 has been in my shop all winter, up to now. I take it off the road when the salt comes, so no hurry. Well, except I'd like to get it the heck out of my shop and be sure it is ready to use come spring.
I did a LOT of work on it. I have been neglecting many things for years. This last fall, when it would barely steer when turning left, and the brake pedal was going to the floor - I finally put it into my shop.
So - my only problem now is the brake system. Note - all is new or rebuilt. Rebuilt calipers in front. New wheel cylinders in back. New master cylinder. Rebuilt brake vacuum booster. New vacuum pump.
I have not really driven it anywhere yet except up and down my driveway. Brakes work good when I first use them, but with repeated use - the pedal goes near to the floor and the brake warning light comes on.
Note - that unlike gas trucks - this has a low-vacuum sensing switch and turns on the brake warning light if vacuum gets too low. I have determined it IS low vacuum making the light come on. Why - I have no idea. I have vacuum-leak tested everything.
I think - but do not know for sure - that excess brake pedal travel is using more vacuum then the vacuum-pump can sustain? This is something I never had to think hard about before. I am wondering if it is possible if the brake shoes in back are not adjusted tight enough and excess travel can do this? I was pretty careful adjusting them (I think) and they are self-adjusting anyway if I drive it around a little.
The soft brake pedal has me perplexed. Absolutely no air in the system. Rock hard when I first stomp on it - but if I hold steady pressure on it - it slowly goes nearly all the way to the floor. It did this before with the old master cylinder. It now has a brand new one and is doing the same. I guess the new one could be defective, but I am doubtful. I just ordered another one to try anyway.
If anyone has any ideas - chime in. I am almost at the end of my rope with this one. Such problems are usually easy fixes.
By the way - I do not need one right now - but I was surprised to not be able to find a new low-vacuum sensor. Seems Ford used them as well as some Dodge-Cummins trucks (with vacuum boosters). Looks like the part is pretty much unavailable for either which is kind of surprising. Ford # E3TZ-12A182-H . Chrysler Part # 04428676.
I did a LOT of work on it. I have been neglecting many things for years. This last fall, when it would barely steer when turning left, and the brake pedal was going to the floor - I finally put it into my shop.
So - my only problem now is the brake system. Note - all is new or rebuilt. Rebuilt calipers in front. New wheel cylinders in back. New master cylinder. Rebuilt brake vacuum booster. New vacuum pump.
I have not really driven it anywhere yet except up and down my driveway. Brakes work good when I first use them, but with repeated use - the pedal goes near to the floor and the brake warning light comes on.
Note - that unlike gas trucks - this has a low-vacuum sensing switch and turns on the brake warning light if vacuum gets too low. I have determined it IS low vacuum making the light come on. Why - I have no idea. I have vacuum-leak tested everything.
I think - but do not know for sure - that excess brake pedal travel is using more vacuum then the vacuum-pump can sustain? This is something I never had to think hard about before. I am wondering if it is possible if the brake shoes in back are not adjusted tight enough and excess travel can do this? I was pretty careful adjusting them (I think) and they are self-adjusting anyway if I drive it around a little.
The soft brake pedal has me perplexed. Absolutely no air in the system. Rock hard when I first stomp on it - but if I hold steady pressure on it - it slowly goes nearly all the way to the floor. It did this before with the old master cylinder. It now has a brand new one and is doing the same. I guess the new one could be defective, but I am doubtful. I just ordered another one to try anyway.
If anyone has any ideas - chime in. I am almost at the end of my rope with this one. Such problems are usually easy fixes.
By the way - I do not need one right now - but I was surprised to not be able to find a new low-vacuum sensor. Seems Ford used them as well as some Dodge-Cummins trucks (with vacuum boosters). Looks like the part is pretty much unavailable for either which is kind of surprising. Ford # E3TZ-12A182-H . Chrysler Part # 04428676.