Vacuum Pump Life Span? Years or Miles

[Matt42]

My 1996 has 77,000 miles on it. But it sits out baking in the Arizona sun. At what point should I begin to worry about the vacuum pump? The last time I drove it, the brake pedal was surprisingly hard in an emergency stop. And now the heater/AC control on the dashboard has gone bad.

 

[fest3er]

Check the soft 'elbow' between the pump and the hard vacuum line. They're known to disintegrate over time.

My vacuum pump lasted around 22 years and 325k miles. Or was it the P/S pump (drive gear) that failed and it was recommended that the vacuum pump be replaced at the same time? (I sure got an upper-body workout driving the truck with P/S, and a lower-body workout braking without the hydro-boost.)

 

[Timd32]

Check out OTC 5613 Vacuum Gauge set, they are under $30. And are really nice, on a budget do the free rental with deposit at the parts store for one.

Should be 8.5" to 25" in of vacuum at different speeds. Pop the hose off and inspect and test it out.

If you have a small vacuum pump you could test the check valve.

There are some tees and hard lines down by the driver's side that pass thru the firewall check that area out.

Under the dash there are some various known issues on the blend door controls or lack of vacuum from the pump. You could try with a helper to use the vacuum pump to test that from the engine bay possibly. Never tried that.

Mines on defrost only, been broke since I had the truck. One day maybe I will try this out.

Low vacuum to the booster should cause a Brake light, you can test that switch with the vacuum pump, should only take like 20" vac light should go off if thats your only Brake issue causing the light if you have one.

Rubber hoses could have issues for sure.

If you have brakes, and blend door issues common to both are the pump and lines.

I rebuilt my vacuum pump at 205k as I had a bad oil leak and it was coming off already. There is a video for the rebuild, pretty decent.

Genos carries the kit.

Good luck on your repairs.

 

[Matt42]

Check out OTC 5613 Vacuum Gauge set, they are under $30. And are really nice, on a budget do the free rental with deposit at the parts store for one.

Should be 8.5" to 25" in of vacuum at different speeds. Pop the hose off and inspect and test it out.

If you have a small vacuum pump you could test the check valve.

There are some tees and hard lines down by the driver's side that pass thru the firewall check that area out.

Under the dash there are some various known issues on the blend door controls or lack of vacuum from the pump. You could try with a helper to use the vacuum pump to test that from the engine bay possibly. Never tried that.

Mines on defrost only, been broke since I had the truck. One day maybe I will try this out.

Low vacuum to the booster should cause a Brake light, you can test that switch with the vacuum pump, should only take like 20" vac light should go off if thats your only Brake issue causing the light if you have one.

Rubber hoses could have issues for sure.

If you have brakes, and blend door issues common to both are the pump and lines.

I rebuilt my vacuum pump at 205k as I had a bad oil leak and it was coming off already. There is a video for the rebuild, pretty decent.

Genos carries the kit.

Good luck on your repairs.

Thanks. I'm going to go thru the diagnostic once I can reassemble the truck's falling-apart dashboard frame. The immediate problem is a stripped knob. But the dashboard structural parts are turning to powder.

 

[GrantP]

Definitely check the elbow as mentioned, especially if you've done any work under the hood lately. Follow the line from the pump up to the connection at the firewall, I've knocked it loose before.

My 97 made it on the original pump to nearly 200k baking in the same AZ sun, I wouldn't worry about it. The only damage the sun did was destroy my paint and turned my dash and dash frame to garbage. That was a fun job.

 

[JeepBuilder]

Sounds like you have low vacuum from a leak. I am rebuilding my vacuum pump right now in the shop. Along with a few other things too. Vane style vacuum pumps rarely go bad unless there are excess hours or miles in our case. Or they eat a foreign object. Like dirt or shavings. You will most likely loose the seal between the Power Steering and vacuum pump and it will drip oil. I used to rebuild two stage vacuum pumps and water ring pumps for the microelectronic's industry. It takes a lot to kill one. The vanes and seal kit can be purchased from Genos. They are Pete Gould parts. Gould gear and electric fixinrams.com I just spoke with Pete two days ago. I needed a drive coupling. The vacuum pump side of the coupler. Pete says they all fail right around 177-180K. The ears shear off making you loose assist to the brakes and steering. Mine were worn and needing replacement. See the pictures in my Dead pedal thread. Pete has the drive couplings made for 61 bucks. They are pressed on as tight as can be and let go with a bang. I had to machine the parts to press it apart. His videos are very informative and even Pete says the vacuum pumps are simple and pretty reliable. It is most likely a leak and for checking that you would check vacuum first at the pump. Then move down stream in the lines. At 77K you are good for quite a while on the pump itself. Get the vacuum gauge and start at the pump. Let us know...

 

[BigPapa]

My vacuum pump AND P/S pump have over 550K on them and all I’ve ever done to either of them was to replace the seal between them as others have mentioned and flush and refill the P/S system with BG synthetic fluid. As JB said, they’re hard to kill.

It’s much more likely you have a broken line or deteriorated rubber fitting. The plastic lines get VERY brittle and will break if you look at them hard. I’ve replaced most of my plastic lines with nylon air tubing and vacuum hose.

 

[Matt42]

Definitely check the elbow as mentioned, especially if you've done any work under the hood lately. Follow the line from the pump up to the connection at the firewall, I've knocked it loose before.

My 97 made it on the original pump to nearly 200k baking in the same AZ sun, I wouldn't worry about it. The only damage the sun did was destroy my paint and turned my dash and dash frame to garbage. That was a fun job.

I may be getting in touch with you. Did you rebuild the dash frame with plumbing cement & ABS strips (as I am doing now) or did you find a new/used one? And where? Mine is turning into powder.

 

[GrantP]

I may be getting in touch with you. Did you rebuild the dash frame with plumbing cement & ABS strips (as I am doing now) or did you find a new/used one? And where? Mine is turning into powder.

I used your approach for the frame, AFAIK new ones are not available and any used ones are more than likely broken too. I was able to get a new replacement dash (not a cover) from Geno's. Not sure if they still sell them. I also replaced the heater core since I had it torn down that far, it had a slight weep.

 

[GAmes]

Somewhere around a million miles I was ordering some stuff from Genos and, on a whim, ordered the vacuum pump vane set. When the seal needed a replacement I found the original vanes were only a fraction smaller than the new ones. The new ones are now residing in a box on a shelf.

 

[Iron Duke II]

Anyone recall if there is a mfg torque spec for the oil feed line between the vacuum pump and engine block?

 

[BigPapa]

60 in/lb or 5 ft/lb.

 

[Iron Duke II]

60 in/lb or 5 ft/lb.

Thanks!

 

[Vaughn MacKenzie]

I have never touched the vacuum or PS pump on my 1996 Ram. Nor my AC. 494,000 miles & all working fine.

 

[NIsaacs]

Somewhere around a million miles I was ordering some stuff from Genos and, on a whim, ordered the vacuum pump vane set. When the seal needed a replacement I found the original vanes were only a fraction smaller than the new ones. The new ones are now residing in a box on a shelf.

Humm...that is like saving a new spare tire, rotate it in and save a used tire. Or not using your headlights on a dark cloudy day, save them suckers

 

[Joe Mc]

Could be wrong as yours is a 96 an mine is a 99, but thought brakes are "hydo-boost" and not vacuum? To your original question, my vacuum pump is original and truck has 255k never had issues

 

[Iron Duke II]

My '96 brakes are vacuum pump assisted.

 

[Joe Mc]

My '96 brakes are vacuum pump assisted.

Sorry, will have to keep that in mind. When did they go to hydro-boost with 98.5 24v?

 

[Iron Duke II]

Sorry, will have to keep that in mind. When did they go to hydro-boost with 98.5 24v?

2nd gen '97 and newer I believe.