Headed out to test the Vacuum. I'll let ya know what I find. Might be a couple hrs.

Again, thanks for the ideas and specs.


Jay

 

The verdict is in......7 in Hg is not enough vacuum to make anything work.


Jay

 

Put a vacuum pump on it tonight. Whooooore of a place, even with the airbox off, but its on, and works good. Power brakes are working again, as are the heater controls.

Thanks guys for all the help, support, ideas..

Jay

 

Glad to hear that, thanks for the update.

 

Hey just wondering, when you replaced the pump did you replace the vac diaphragm/pod that is mounted on the pump aswell?

I am working on a 97 f250 7.3L, same story, after a couple brake applications there is no assist, just a rock hard peddle.

With vac gauge on pump at idle only 7hg. diaphragm holds 20in with the vac pump on it. I have a spare pump that i saved when i changed the diaphragm on a e350 cube( only changed the pod because the pump was such a ***** to get off lol)

Both pumps feel the same when rolled over by hand tho and i dont see how the pump it self could actually fail since all the vacuum appears to be made in the pod.

Just trying to avoid doing this twice. Should i put the pump on or wait and get an entire unit with the pod?

Also with vac pump on booster it doesn't hold any vac, anyone else ever test one? On the e350 i fixed about 6months ago i think i remember it also not holding vac when pumped up. But after changing the vac pod on pump it worked fine.


THANKS in advanced everyone.

 

When the pump itself goes bad it's usually because of the front bearing. The rear bearing is a set of ball bearings that can be greased but the front is a set of non serviceable needle bearings.

I've replaced two vacuum pumps, one with a failed needle bearing and the other with a ruptured diaphragm.

 

Aparently the "Brake" idiot light is burnt out as well

 

You need a vacuum pump for sure. And tehy come with the diaphragm on the pump when you buy them. That or do a hydroboost conversion...

 

i figured i needed the pump. already got a new one on the shelf that i saved, but i used the diaphragm on a different one. my question is if the pump alone will fix this or if i need to buy another one with diaphragm

 

Yeah that's a crap shot. Typically the bearing goes out and then destroys the pump diaphragm.

 

Pump is on order. Will be installing tomorrow night

Can anybody tell me if the booster should hold vac when pumped up with a hand vac pump. This one wont hold vac at all, I tested on the booster on my gasser and it held 20hg.

 

no they dont . you can buy one that does though i think theyre called lossless boosters? just do the vac. pump first. im bettin that fixes your problem.

 

thanks Ken

 

zero loss booster

 

The idea of a no loss booster makes sense. Any idea what the advantage to a normal booster that wont hold vac would be? There must be some kind of reason they installed that kind at factory