Vacuum pump noise, stiff brake peddle, hard shft

[84diesel6.9nonturbo]

I have a 1984 f250 xlt super cab 6.9 non turbo i recently purchased it for $2500. It has 148k miles. Its very clean. The vac pump kinda chuggs loudly and the c6 is shifting rough at low rpm. At high rpm it shifts smooth. I already replaced the transmission modulator... it did not improve the hard shift. I also have a stiff brake peddle. The booster makes a brief hiss noise, like its releasing pressure shortly after shuting the engine off. I believe the vac pump going out. Maybe my booster too. Any thoughts? Also my starter has just started grinding yay!

 

[no mufflers]

I just replied in your other thread but here it is anyway. yes, the brakes are powered by vacuum and the transmission needs vacuum to shift.

 

[OLDBULL8]

Most likely the Vac pump is causing most of your troubles. Don't just go throwing parts at it.

You need a Vacuum gauge.

At idle the Vac pump (VP) has to pull 22 inches of Vac. minimum. A new VP will pull 28 to 29 inches.

Don't mess with the VRV (Vacuum Regulator Valve) on the IP until you have a Vac gauge.