2nd Gen Non-Engine/Transmission Suddenly hard brake pedal

[milto]

Sur could use some suggestions. The following has happened about 3 times in the last year and a half.



Go to use the brakes and they feel fine, then go touse them quickly again and the pedal will feel real hard and very little brake, rather scarry!!!



Leave it sit or drive a little and everything will be back to normal. There doesn't seem to be any special set of actions that this will happen. It has happened twice pulling the 5th whheel and once when just normal driving.



Thanks for any help.



Milt

 

[bmoeller]

Sounds normal when pumping the brakes or a lot of use in a very short time, as when plowing snow in a parking lot. Basically, the vac. pump can't keep up with the demand.

 

[biggy238]

I agree on the lack of vacume from the pump. Check for leaks.

 

[JRichard]

Another idea

Dont discount the possibility that the master cylinder could cause this. Ive had that problem in chevies before but not in my dodge.



Jake

 

[Joe Mc]

If the vacuum pump can't keep up with the demand - is there some low-tech way to install a reserve tank maybe with an old 1/2 gallon juice can? I recall a neighbor of mine placed the paper cover from a V-8 juice can on the stock vacuum reservoir on his Town Car (back in the 70s). I had no idea what the can was for until I saw the V-8 juice label and asked, "what the heck is that for"?