I've got a 2001 E-350 w/7.3. Does anyone know how much vacuum the pump puts out. The reason I'm asking is the brakes are hard to stop the vehicle. I replaced the booster and that helped with the hardness of the pedal but it didn't take care of the stopping. I still have to stand really hard on the pedal to get it to stop.

 

Our trucks don't use vacuum to boost the brakes, it gets its boost from the powersteering pump. Be sure to use ATF in the powersteering pump, not powersteering fluid.

 

I tried to find the vacuum specs on my Ford dvd manual, but I didn't. It's been quite a while since I worked on a 7.3 with the mechanical vacuum pump. I want to say less than 15 inches of vacuum will give you hard pedal problems. Have you installed a vacuum gauge to the pump and checked it yet? You could attach a hose to the pump's connection and draw on it to see if the diaphragm is ruptured. Are the HVAC vents functioning normally?

 

Roland, how does vacuum effect the brake pedal?

 

Rick,
He has an E-series van. Different animal. They have the vacuum assist brakes on the E-150 thru 350. E-450 has hydroboost.

 

lol, OK. I was wondering what the heck was going on. Didn't dought you, just wondering what I was missing.

 

Yeah it's been awhile since I've had to work on one of these as well. I do know that the vacuum I'm putting out definately isn't enough to get everything working the way it should as I only have 5 lbs. vacuum. But I do know that when I replaced the brake booster the pedal became softer. That is the reason for my question.

 

Sounds like the vacuum pump is next on the list.

 

Yup sure does. It's gotta be that as everything else is working. When I get it swapped out will let you all know what the vacuum is

 

Cool! It's been over 10 yrs since I replaced one and I didn't bother to check the vacuum reading then. It will be some good info for the memory banks. We have a few vans, that we contract on, at our company. I can pass on the info to the mobile mechanics who work on them. I work on them, occasionally, when they come into our shop for service.

 

Well the answer to my question is... New vacuum pump will put out between 25 - 27 in. vacuum. It was definately the vacuum pump. Thanks everyone

 

Glad to hear that fixed your problem.

 

I have 2001 7.3 liter turbo diesel E-350. I have replaced the vacuum pump 4 times over the last four years. What causes the pump to fail?

 

What did fail?

 

pump starts to make a lot of noise. Lose pressure on brake pedal. The first press on the pedal has some pressure. The second has almost none. I have had it replaced at two different dealers hips and two different independent shops.