Just bought a 94 Aerostar w/ 42000 mi. My brother & I split the cost on it & we both love it! So much so, that we fight over who gets to drive it. The worst part is that we both own Porsches! Go figure.

Anyway the problem is that the other day, i had just started it up & pulled out of my driveway & had to really stand on the brakes. They seemed not to grab at all, immediately after they seemed fine. What should I look for? Vacuum? Master Cylinder?

Any help would be appreciated

Thanks

 

Congratulations on discovering the joy of driving an Aerostar. If you ever want to get rid of your Porsche, just send it to me.

Regarding your brakes, did the pedal feel soft or go to the floor, or did it feel firm but just didn't grab? From your description, I'm guessing the latter. How much time between starting it up and applying the brakes? For starters, I would check the vacuum lines, including the check valve. Also, make sure the booster can hold a vacuum.

 

[updated:LAST EDITED ON 17-Sep-02 AT 11:08 PM (EST)]Thanks for the reply, I would say less than 15 secs from starting engine to stop. Probably closer to 10. Can't recall firmness, but if the pedal had sunk to the floor, I'm sure I would remeber that. However, they definetly did not grab. Where is the booster? On a Chevy van I had (Piece of Crap) it was on the underside of the hood.
What would be the best way to check for good vacuum?

P.S. My company has 5 vans all are Fords (4- E150's 1-E250). Miles range from 55,000 to 285,000 and Love them all! Last summer I took the oldest 1 (it was the only one with crusie control) a '95 260,000mi (at the time) 4.9 6cyl owned since 20,000 (the engine has never been opened up) on a 2500 mi round trip to Chicago to pick up some old furniture. It ran like a top! That's why we went with the Aerostar.

 

Sorry I didn't get back sooner, I've been having trouble trying to post to this message from my home computer. I tried to "reply with quote" and every time, the computer got hung up. Finally tried just "reply" and it worked.

Anyway, the booster is located between the firewall and the master cylinder. To test it, you would need at least a vacuum gage and a way to tee into the vacuum lines. Then you could start the engine and let the engine vacuum empty out the booster. Turn it off and see if you lose vacuum. If you do, you'd have to isolate portions of the vacuum side of the brakes to see where the leak is.

A simple test would be to pump the brakes with the engine off. You should feel the pedal gettting harder as the vacuum gets dumped. Pump until you notice no change in the pedal feel. Then push the pedal down and hold it down. If the pedal sinks to the floor, then you have a hydraulic problem. If not, start the engine and see if the pedal gets lower with the same pedal force. If not, then you have a vacuum problem. From there, you can troubleshoot the appropriate part of the system.

I would also check the rear brake adjustment. I've noticed on my van that the adjusters don't work and I have to get in there and adjust them regularly. I've replaced the adjusters but they still don't work well. Grrr, I have better things to do with my time.

 

The pedal drops to the floor. well then you have vaccum, you have a leak or a bad master cyl. Since Rear drums control the pedal height, I would start there.