Vacuum pump leak .... Fixed
10-25-2006, 02:12 AM
#1
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Vacuum pump leak .... Fixed
Had a great knuckle scraping adventure this past weekend. I fixed the leaky seal in my vacuum pump. I had to do it twice. A little background on it ...
I had noticed that my truck had a lot of blowby. I learned that it could be caused by a bad seal in the vacuum pump. I had looked at the vacuum pump and saw that it was oily and wet on the underside of the pump. I decided to reseal the pump and purchased a reseal kit to do this job.
The leak occurs between the vacuum pump and power steering pump, where the two meet. Inbetween the two pumps is a seal retainer that has a single lipped rubber spring seal that prevents oil from leaking out from the vacuum pump. When this seal fails, the vacuum pump starts leaking oil and sucking in air at the same time. This extra air gets vented into the timing case (where the vacuum pump oil drain is) and causes more blowby. A really bad vacuum leak can cause the same symptom, but your vents and cruise control will likely not be working if this were the case.
The single lip seal normally wears a groove into the power steering pump shaft like this:
It eventually will start leaking more as the groove gets larger. The seal I used to replace the original is a double lipped vitton rubber seal. The double lip seal sits on both sides of the groove so that the groove is no longer an issue.
To get to the seal you need to pull the vacuum pump out of the truck. This is a very ackward pump to work on, since its location on the engine is difficult to get to. You can either pull the vacuum pump and power steering pump out together and then service it, or you can seperate the two in the engine compartment. I reccomend pulling the entire thing. You will lose some of the power steering fluid this way, but it gives you a chance to replenish the lost fluid with fresh fluid (always a good thing) and re-aligning the two pumps together is way easier out of the truck.
This following shot is the rear housing, where the vacuum pump shaft meets the power steering pump shaft. The round cylinder in the middle is the seal retainer, and the black ring inside the retainer is the seal that gets replaced.
If anyone would like more info about this or the process then please let me know. I did this twice this past weekend mainly because I dislodged the new seal when I re-aligned the pumps in the truck and made a bigger oil leak.
. When I did it the second time it went way smoother, and learned several shortcuts to doing it that I will gladly pass along if anyone is curious.
I had noticed that my truck had a lot of blowby. I learned that it could be caused by a bad seal in the vacuum pump. I had looked at the vacuum pump and saw that it was oily and wet on the underside of the pump. I decided to reseal the pump and purchased a reseal kit to do this job.
The leak occurs between the vacuum pump and power steering pump, where the two meet. Inbetween the two pumps is a seal retainer that has a single lipped rubber spring seal that prevents oil from leaking out from the vacuum pump. When this seal fails, the vacuum pump starts leaking oil and sucking in air at the same time. This extra air gets vented into the timing case (where the vacuum pump oil drain is) and causes more blowby. A really bad vacuum leak can cause the same symptom, but your vents and cruise control will likely not be working if this were the case.
The single lip seal normally wears a groove into the power steering pump shaft like this:
It eventually will start leaking more as the groove gets larger. The seal I used to replace the original is a double lipped vitton rubber seal. The double lip seal sits on both sides of the groove so that the groove is no longer an issue.
To get to the seal you need to pull the vacuum pump out of the truck. This is a very ackward pump to work on, since its location on the engine is difficult to get to. You can either pull the vacuum pump and power steering pump out together and then service it, or you can seperate the two in the engine compartment. I reccomend pulling the entire thing. You will lose some of the power steering fluid this way, but it gives you a chance to replenish the lost fluid with fresh fluid (always a good thing) and re-aligning the two pumps together is way easier out of the truck.
This following shot is the rear housing, where the vacuum pump shaft meets the power steering pump shaft. The round cylinder in the middle is the seal retainer, and the black ring inside the retainer is the seal that gets replaced.
If anyone would like more info about this or the process then please let me know. I did this twice this past weekend mainly because I dislodged the new seal when I re-aligned the pumps in the truck and made a bigger oil leak.
. When I did it the second time it went way smoother, and learned several shortcuts to doing it that I will gladly pass along if anyone is curious.
10-25-2006, 06:26 AM
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dont feel bad J.R. i also did it two times, for the same reason you stated.
i didnt take out the power steering and wish i would have, it was way to tight of a space(i had tranny lines right in the way), but sucked out the old ps fluid with a pump.
the hardest part for me was getting it in and out.
i didnt have much blow by, but i had oil leaking, when the engine would come up to operating temp.
glad you got it done.
dieselfan
i didnt take out the power steering and wish i would have, it was way to tight of a space(i had tranny lines right in the way), but sucked out the old ps fluid with a pump.
the hardest part for me was getting it in and out.
i didnt have much blow by, but i had oil leaking, when the engine would come up to operating temp.
glad you got it done.
dieselfan
10-25-2006, 08:09 AM
#4
....another "helper" in this process. I have two studs with a slot cut in the top of them. I screw these studs into the timing case and it aids in holding the vac/pwr str pump assy and gasket in place while I align it. After it "falls" into place I can use a screw driver to remove the studs one at a time and install the original bolts.
10-25-2006, 09:29 AM
#5
Yeah I did mine a couple years ago in a parking lot................ Not a very fun thing to get off or on that pump!
Jr Did you just replace the seal on the shaft??
I bought a seal kit from Dodge (came in a Cummins parts bag) came with the seal, gaskets and Orings for the whole deal. It was around $30
Good job. Thanks for the pics, I'm sure those will be helpful.
Jr Did you just replace the seal on the shaft??
I bought a seal kit from Dodge (came in a Cummins parts bag) came with the seal, gaskets and Orings for the whole deal. It was around $30
Good job. Thanks for the pics, I'm sure those will be helpful.
10-25-2006, 09:38 PM
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i noticed a little more smoke than usual and an slowly doing some maintenance!
might be a nice weekend proect to do.. ( trying to save money)
tool: any chance on a cummins part number for the rebuild kit?
might be a nice weekend proect to do.. ( trying to save money)
tool: any chance on a cummins part number for the rebuild kit?
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10-25-2006, 11:28 PM
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10-26-2006, 03:03 AM
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Yeah I did mine a couple years ago in a parking lot................ Not a very fun thing to get off or on that pump!
Jr Did you just replace the seal on the shaft??
I bought a seal kit from Dodge (came in a Cummins parts bag) came with the seal, gaskets and Orings for the whole deal. It was around $30
Good job. Thanks for the pics, I'm sure those will be helpful.
Jr Did you just replace the seal on the shaft??
I bought a seal kit from Dodge (came in a Cummins parts bag) came with the seal, gaskets and Orings for the whole deal. It was around $30
Good job. Thanks for the pics, I'm sure those will be helpful.
When I did it the second time I had figured out exactly which nuts and bolts you have to take out and which bolts you don't need to remove until the unit is out of the truck. There are two bolts that hold the entire assembly to the timing case. Those need to come out. There is a secondary nut that holds a wiring harness on place on the stud holding the PS and VP together on the upper outboard side. There is a nut on the lower inboard (towards the engine) stud holding the rear portion of the pump to a support bracket on the block. That nut has to come off too. The PS lines need to come off, there are only three. The oil feed line on the vacuum pump needs to come off too, there is no drain line to worry about. Oh and disconnect the vacuum line too. That is all to be removed. Then grab both the VP and PS pumps and pull straight back. It will pop right out. If anyone wants pictures showings where all of these bolts are I will be more than happy to take some shots.
10-26-2006, 09:35 AM
#11
Thanks JohnH.......
Sadly I know longer have the part number.
I had kept the bag the new kit came in and put the old seals and gaskets in the bag. Unfortunately the toolbox I put the bag in was stolen out of the back of my truck while at a motel last summer....
I was able to walk in and pick it up from my friendly Dodge dealer for about $30 Cdn.
Sadly I know longer have the part number.
I had kept the bag the new kit came in and put the old seals and gaskets in the bag. Unfortunately the toolbox I put the bag in was stolen out of the back of my truck while at a motel last summer....
I was able to walk in and pick it up from my friendly Dodge dealer for about $30 Cdn.
10-26-2006, 11:38 AM
#12
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Tool, you are lucky, my friendly neighbourhood Dodge dealer wanted $85.72 for that same seal kit. You gotta love no competition.
So, I picked up the kit through the local cummins dealer for $14.63 plus tax.
I find they aren't that bad to do, but I never look forward to doing them either. Too many other things to be done, on customer stuff.
Anyway, Excellent write up on the procedure JR, keep up the good work
So, I picked up the kit through the local cummins dealer for $14.63 plus tax.
I find they aren't that bad to do, but I never look forward to doing them either. Too many other things to be done, on customer stuff.
Anyway, Excellent write up on the procedure JR, keep up the good work
10-26-2006, 04:29 PM
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Thanks.
Would be cool to see a full how to, and any tips on getting to toughs hard to get bolts in/out, and torqued down ….
Two week-ends ago, I replaced my PS pump, thought I’d be smart and just pull the pump Hours later, after about 20 ins and outs I finally got that dang coupling to line up … I’ll never do that again. 
Would be cool to see a full how to, and any tips on getting to toughs hard to get bolts in/out, and torqued down ….
Two week-ends ago, I replaced my PS pump, thought I’d be smart and just pull the pump
Hours later, after about 20 ins and outs I finally got that dang coupling to line up … I’ll never do that again.
)
10-26-2006, 09:23 PM
#15
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You might be on to something there... " Its the Shipping"
Sure it is, I could pay the 14 bucks and change from cummins in hongcouver, air freight it up here, and it would still only be 54 bucks. Soooooo, freight is out the window. Any other ideas
Anyway, doesn't matter where its cummin from, its all in the same bag, albeit with dodge parts stickers on it. but that is ok by me, everyone has to make a dollar somewhere.
Sure it is, I could pay the 14 bucks and change from cummins in hongcouver, air freight it up here, and it would still only be 54 bucks. Soooooo, freight is out the window. Any other ideas
Anyway, doesn't matter where its cummin from, its all in the same bag, albeit with dodge parts stickers on it. but that is ok by me, everyone has to make a dollar somewhere.