Front calipers and rear wheel brake cylinders have been replaced: no change. If pedal is pressed very lightly and "idiot lights" don't come on, problem is greatly lessened. When pressed hard enough to light up anti-lock brake and brake idiot lights on dash, problem is more aggressive, the harder you push the pedal, the worse the problem. When left to sit for 1 hour, goes back to normal. Van has 17,000 miles, was a police surveillance vehicle, was very well maintained, saw very few miles, is in otherwise as new condition

Battery is brand new, cabls are clean and tight. It starts fine when cold. After a long trip it drags like it doesn't want to start. After it cools down it starts up fine.

I own a 1991 Ford E250 Cargo Van - The transmission will not engage in gear to go forward, reverse works fine, I've dropped the pan replaced the oil filter I've added Trans X and still will not engage in any of the gears to drive forward , only reverse works. is there any quick fix for this ? maybe a vacuum line or a possible linkage problem ?
The transmission started disengaging when I would come to a stop I would have to rev up the engine to engage the transmission , until one day it just stopped and would not engage. Thanks

tanks both front and back as the part is 300.00

it shakes hard and I want to know if its the fuel system or a blown head gasket

How does one repair this ? and How do you repair this ?

So my van was running, but real bad i checked spark plugs the gap was off alot i got new spark plugs and gapped them properly now my van wont start ?

This vehicle has had a steering problem ever since it was purchased new.
Numerous repairs have been made but it still requires a firm grip and concentration as it pulls from side to side. It IS controllable and does well in the event of a high speed blowout but is tiring to drive.
AS far as I can recall nothing has been done to the side arm.

The A/C needs recharging every year or two. Had it retrofitted but still seems to leak. Had Leak repaired - it still seems to leak.