Jacobs vacuum pumps!

[jhenderson]

My vac pump quit yesterday. When I called Cummins I found out they are on national back-order. On top of that, they have gone up in price almost 100%. I researched prev. threads and found Delphi makes the vac. chamber, part # POD-4342. I went on their website and found they make the vac pump for 7. 3 Fords, and it uses the same vac chamber. I bought a reman vac pump for a 7. 3 from NAPA for $116, and swapped chambers with my pump, because this is almost always where the failure happens. This solved my immediate problem,but I wonder if someone sharper than me, might be able to find a source for the vac chamber alone. It would have to be FAR less costly than a complete rebuild.

 

[HBarlow]

Congratulations on a great solution when you couldn't easily and quickly buy a solution.

I remember several years ago someone posted the information about Delphi being the OEM but the only application mentioned at the time was a mid-80s GM diesel power booster, IIRC.

 

[abrankod]

Rock Auto has the pod sections available separately... I did this EXACT repair because there was no way I was paying more than necessary for the whole pump.

Did you change the oil in the little camshaft compartment? If so, what did you replace it with? I used a little non-detergent 30WT oil that we use for our power-washer pump.

-Dan

 

[jhenderson]

Where did you find the part number for the pod at Rock Auto? I have looked at their online catalog and couldn't find anything. As for oil, I transferred the oil from the rebuilt to my old housing.

 

[abrankod]

Strange, they have taken down the listings for the pods by themselves. I'll check exactly which number I have and I'll post some places to get it for under a hundred bucks tomorrow.

-Dan

 

[jelag]

I had a group of Fords with this set up on it... we found that most of the failures were from the reed valves not sealing and the pump wouldn't pump and hold... We decided to give the pump a shot of oil... a table spoon or so once a year at the same time we checked the anti-freeze for the winter... .

We'd pull a vacuum line from the power brake booster and give the line a a table spoon or two of light oil, usually a hydraulic oil... the pump would suck up the oil and it would spit out a great deal of dirt through the filter on the side. .

This didn't stop the failures but slowed them down... at the same time, we'd check the vacuum with a gauge and should expect to see 22-25" of vacuum for the brakes and chambers under the dash to work (heaters)

We did this at our own risk. . I know that we used to stock one spare pump...

Just my thoughts on this. .

 

[CKelley1]

as our pumps fail we change to the bd brake. no more vacuum pumps to fail and more breaking power

 

[jelag]

CKelly1

I've sold a lot of customers PacBrakes who have removed the Jacobs brake... I understand there is an option to having the existing Jacobs system... But a lot of these guys have bought the Jacobs unit in good faith, just like I owned all those Fords...

They are looking for a way to reduce cost, and maybe keep the system... I'm just trying to extend the life of what they own...

I personally found that this pump is a poor system at best, when I owned the Fords... .

 

[PintoHauler]

JHenderson,



The repair you speak of last October, swapping just the vacuum chamber from a reman part for the Ford, I have a question if you would be so kind. Can I just remove my vacuum chamber from my pump without removing my pump from my truck, of does this failure/repair necessitate removing the pump anf doing the swap on a bench? Any gotcha's, or is it pretty straightforward?



Many thanks in advance,

Dave

 

[mitchC]

Vacuum pump change

I changed one a while ago. I believe you would have a mess as the oil will run all over and be dam hard to get back in there and reasemble the vacuum chamber. 1/2 inch breaker to releive tension on serpentine and remove belt over the pulley and then get after that pump.

Good luck

mitch

 

[PintoHauler]

Mitch, you sound like a guy who has been there. I hate to appear ignorant, and I am a pretty good mechanic, but have never tackled that serpentine belt. I realize only loosening the tensioner would be necessary, not removing the belt, but I have not seen a diagram of exactly how that tensioner secures, loosens, etc. With the fan shroud in place, it is a bit hard to see enough under there. Is it easier to get to from the bottom? I haven't looked there yet. Do you know of a picture on this board that shows a diagram of the tensioner, or could you give me a few pointers as if I was looking at the tensioner from the front of the truck?

Did you put a whole new pump on or did you just replace the diaphragm? I see Geno's Garage has the replacement diaphragm as well as the suggestion about NAPA and the reman. Ford pump, but Geno's is out of stock on the new Gould pump with larger diameter pulley. For long term reliability, I think that is the route to go. I would also like to explore an electric vacuum pump. Don't know if one could be found that would produce enough vacuum, but this thing can't be that unique.

Any assistance is appreciated.



Dave

 

[mitchC]

Mine is an 06 but if you get on your back looking under the truck from front to rear its to your right of centerline of the crank pulley and up in there aways get a good light. You will see a square 1/2 indent in the tension pulley. place a long rachet or breaker bar in that square and pull it to the right side of the truck. Two hands can be helpful. I use a little comelong to hold the tensioner over but a rope would also do just fine. When your looking up there the square is on the engine side of the tensioner.



I just replaced the vacuum chamber. Ironically I just did it again today. The reman. didnt last. Maybe the new one is the way to go for reliability. It is also necessary to reposition the outlet pipe out of the chamber to match the port off the original.

If the one from Geno's is the direct replacement for the jacobs brake and new as apposed to rebuilt I would go that route.

good luck Mitch

 

[Okie-Go]

I posted in another thread not long ago about this fix. Parts man just changed the diaphram and the oil. working fine.

Okie