Bad brake booster?

[thescot]

In a previous post I made mention of very weak brakes. Yesterday I noticed when I apply the brakes the rpm goes up about 300 rpm, not momentarily, but as long as I hold the pedal down. Guess Im goin deaf, but I dont hear any vac leaks or hissing like typically experienced on other vehicles Ive had. Sound like the culprit?

 

[tarry99]

In a previous post I made mention of very weak brakes. Yesterday I noticed when I apply the brakes the rpm goes up about 300 rpm, not momentarily, but as long as I hold the pedal down. Guess Im goin deaf, but I dont hear any vac leaks or hissing like typically experienced on other vehicles Ive had. Sound like the culprit?

As mentioned in that other post you need to check the booster, the line and fittings from wherever the vacuum source is coming from..............I would say you do have a vacuum leak somewhere associated with the Booster system.
Sometimes you can use a non flammable liquid and hit the area while running when the brakes are applied. Should not be that hard to find.