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Vacuum Pump, PS Pump, & Steering Gear

5K views 31 replies 6 participants last post by  GAmes 
#1 ·
Yesterday I started taking the truck apart to have my steering gear rebuilt by Blue Top and to rebuild the vacuum pump and PS pump on my own. I have no shop and not even any trees so I'm not even a shade tree mechanic. Most of the time that's fine in West Tx other than when it's over 100*. Before I started the project I checked the weather forecast and saw no chance of rain for 10 days and no fluctuations in the weather, highs @ upper 90's, lows @ mid 70's, & wind @ 5-15mph.

Working on and off I had everything removed by this afternoon and had the 3 parts in the title laying out on cardboard and stripped apart cleaning them. At about 3:15 skies are nice and clear it's hot and I'm thirsty so I go inside to get some water and cool off for a few minutes. At 3:45 I heard thunder and looked out the window and saw dark skies. By the time I got my boots on and ran way out to the truck the skies had been just dumping rain; 3/4" in 15 minutes. Once I got outside I put up the most important stuff first (basically slamming the hood and throwing all the expensive tools in and under the truck) and then moved my parts. Parts were rained on hard for about 7-8 minutes.

As mentioned earlier I'm sending the steering gear to Blue Top for rebuilding, do I need to completely strip everything apart on it and check for rust and whatnot before I send it or am I fine as it is?

As for the vacuum pump & PS pump I'm taking them all apart anyways for all new seals and bushings. I'm not as concerned about the vacuum pump as the PS pump because of all the small springs and other fine ancillaries.

Most of this post was for me to think out loud and type this all out to calm down because I was extremely angry earlier. Thoughts, inputs, suggestions?

P.S. The 2 fittings hanging on the side of the PS pump (lots of P's & S's around here lol) are slightly bent from me trying to pull the hoses off before I realized the rubber has been melted to the fittings since 1998. Does this call for a new reservoir or can they current ones be bent back or new ones installed? I know nothing about hydraulics and pumps so maybe this endeavor was a foolish idea but nonetheless I've been wanting to rebuild the pumps and learn something new along the way while also saving money.

P.P.S. It's now sunny outside without the slightest hint that there was a torrential downpour earlier.
 
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#2 ·
I doubt if water would have gotten inside but if it did there should have been enough oil to keep them from rusting that fast.

If the small return tubes are bent closed they won't straighten back out without cracking the tubes trying to round them back out.
 
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#3 ·
For the rebuild of the vacuum pump/PS assembly, it's worth the time and money while it's off to get the dual lip seal kit from Geno's which is from Gould Gear and Electrical. The kit has the tools to do it right, and the seal is better than the single lip original which is a fail point.

Rebuilding mine this weekend. Link to video here and kit is inexpensive and superior.



https://www.genosgarage.com/product/gould-vprk-9602/engine-rebuild-kits-2
 
#4 ·
#5 ·
Cummins has a single lip seal, not dual and rides a different and often worn location on the shaft. Is that a superseded Cummins seal? Not everyone has moths eating their wallets and time to play lego assembler and guess which sizes work for this. Whats the time worth to go gather dimensions? To each his own.
 
#10 ·
I took this picture and posted it YEARS ago when the same misinformation was posted on a forum. If your pump has a single lip seal inside it is not from Dodge or Cummins.



At that time a kit was about $11, so it hasn't gone up in price very much. The wallet angle is definitely in favor of the Cummins kit. No one with a brain spends $60 for a $15 kit with $2 worth of PVC when they are aware of a better alternative.
 
#6 ·
Is a common for the vacuum pump to dump oil? Mine started puking oil on the ground. It's clean on the bottom so it's pretty clear it's got a good leak.

It's always had some residual oil on it.
 
#7 ·
I've planned on using the Cummins 4089742 seal because it's half the price, made by Cummins, I have a low budget and haven't seen any meritable evidence through searching the forums and scouring the internet. Not worth the extra $16 in my mind. That being said if someone insists on me using it then pm me and I'll send you a shipping address.

I have come across that video elsewhere but it's still useful on this thread for the lurkers out there.
@alanack6795 IIRC the vacuum pump is a notorious "oil letter" just like the valve cover gaskets, the rear main, the oil pan, etc... (are there actually any seals that provide a dry sealing edge on these motors?)

The return tubes aren't bent fully shut but it isn't a small bend either. I'll try returning them to normal, if not then I'll either find a reservoir with good ones or talk to the hydraulic shop making my hoses and see what they say.
 
#8 ·
On the topic of hoses is there something I can do to keep the rubber from melting onto the lines? Even if I run a PS cooler that only cools the fluid and not the hose. I just don't like the idea of the rubber hoses being melting like heat shrink tubing to the lines. I work for a gutter business so I have access to lots of aluminum and metal brakes and fabbing up a heat shield is no problem if someone thinks it might be worth it.
 
#12 ·
Only if you knew of the Cummins kit in advance.
 
#15 ·
GAmes it's the instructions that cost so much, pvc pipe is cheap but his kit comes with 2 sets of instructions, written and dvd.
Got to be the instructions! :hehe:
Sure glad my truck doesn't have one of those pesky vacuum pumps, hydra-boost brakes and a electric vacuum pump for the HVAC. :thumbup:
It's so much more fun working on a air compressor than to replace a simple seal in a vacuum pump. :banghead:
 
#21 ·
GAmes it's the instructions that cost so much, pvc pipe is cheap but his kit comes with 2 sets of instructions, written and dvd.
Got to be the instructions! :hehe:
The Cummins kit has written instruction so I sure hope the DVD isn't the same as the FREE video posted, IOW more complete. For instance, there is no mention of removing the engine oil pressure sender as a precaution from breaking it when the two pumps are slid back out of the gear housing. There wasn't the hint to remove the pressure valve on the PS pump while it is on the bench and cleaning the screen. For $45 it ought to be a lot better than the on line video or the written instructions that come with the Cummins kit. I did like the part at the end about removing the seal housing if you forget the star wheel. I've done that, but managed to overcome the problem by a different method. (Luck played a huge hand there)

I do have to give thanks to thor363 for helping me zero in on an oil leak that has been getting steadily worse over the last 3000 miles or so.
 
#16 ·
I don't know why you would need a engine driven air compressor unless you had air ride or air brakes.

With the 88-96 trucks excluded. The gear driven vacuum pump is completely overkill for trucks without vacuum brakes.
 
#17 ·
Came with the engine, mounted a couple of semi air tanks to the truck, I can run air tools, clean parts, and air up tires out in the field. Pumps a lot more air than a 12 volt electric pump, doesn't take up space like a portable with a gas engine



I like the idea of adding air ride some day.
 
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#19 ·
Pretty common on MD trucks and buses, mine's air cooled but they also come water cooled, trick is finding the proper size PS pump to work with your truck. My engine came out of a bus and the 10 gpm PS pump that came on the engine flowed more than my F-450's hydra-boost could handle, luckily I already had a 6 gpm pump from the original conversion.
Also they will not work with the pump mounted throttle linkage Dodge uses, notice my throttle cable just behind the FSS mounting bracket.

 
#20 ·
I must say I do like the sand colored engine.

So to confirm, that’s an air compressor in lieu of the vacuum pump or on top of a small vacuum pump? And what’s its capacity?

Someday when I get around to putting throwing a Cummins behind a Ford I’ll be sure to do this.
 
#22 ·
That's Cummins Beige, Cummins used that color until the late 80's, around the time Dodge started putting them in pickups.
My compressor is around 10 cfm, they make a twin cylinder 15 cfm unit that fits these engines but it's longer and interfere's with a pickup's side motor mounts, for a pickup install with engine mounts on the side of the block only a single cylinder compressor will work.
The compressor bolts on in place of the vacuum pump, for apps with vacuum power brakes you'll need the vacuum pump.
Ford super duty's with hydra-boost brakes have a small electric vacuum pump to operate the HVAC and don't need the engine mounted vacuum pump.

During the original conversion we direct mounted the ps pump and eliminated the vacuum pump, when I got the replacement engine to build the air compressor came with it, having driven semi's for 30 years I was used to having an onboard air supply, figured I may as well put it to use on my F-450.
 
#23 ·
My oil pressure sensor has intermittently worked the last 3 years and now would be the time to replace it since everything is out of the way. I’m reluctant to actually replace it though because I know it doesn’t actually provide an accurate reading. Is it worth replacing it or not? If I did I would go with Cummins brand but I don’t want to spend the money now and have the same thing happen again in 6 months.

Besides the oil pressure sensor is there anything else I should do while the area is clear?
 
#25 ·
You need something for monitoring oil pressure. if you don't trust a Cummins sender to last for more than 6 months now would be an easy time to plumb it for a mechanical gauge. In my case, the sender has worked well for several hundred thousand miles but I do have an electrical sender in the top of the oil filter housing that is wired to a toggle switch that is also wired to my fuel pressure sender. My fuel pressure gauge is an oil pressure gauge at the flip of a switch. The thing is, the pressure at the filter housing is significantly higher than the pressure at the port in the oil galley. When the engine is cold the pressure pegs the 100 psi electrical gauge, so I seldom have it switched to the oil position.
 
#26 ·
Thanks for the help with these questions.

Is my doubt of the Cummins sensor functioning probably in the near future too picky?

I’m inclined to leave it as is because I t’s worked fine the last 4 months but there’s also times where it bounces all over gauge with little rhyme or reason to the pattern. This has gone on for the last 35,000 miles over a couple years.
 
#27 ·
One other thing you can do, that I mentioned previously, is clean the screen in your power steering pump.



 
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#29 ·
I ended up having to buy a parts store pump for just the reservoir. I went and checked the local junkyard and couldn't find a single Saginaw pump that had dual return barbs and the guys behind the counter looked at me like a cow staring at a new gate. Scoured the internet and went to every parts store in town but nobody sells just the reservoir.

Anyways, after some research on the forums I decided that I would rob the housing and rebuild my PS pump due to the 4-5 "free" replacements (my time isn't free & neither is the fluid even if the pump is) and I'm sure glad. After tearing there's down I saw why they all leak. The machined surfaces were gouged and not flat, the o-rings and seals were much thinner than my Gates #350590 rebuild kit contained and the parts store pump used only rounded o-rings instead of the squared ones in the rebuild kit and old pump. The parts store pump also looked like the flow and pressure mods were already done only they added shims to the flow piston which would jack pump pressure too high. The bushing and shaft seal were actually new in the pump (they're not always replaced) but they were both pressed in WAY TOO tight. And to top it all off the parts store pump had something reminescent of DOT 3 inside of it. It certainly wasn't PS fluid and it wasn't quite ATF. It was clear and had little lubricity to it. Seemed like a 50/50 mix of DOT 3 and acetone...

I did rob all the internals off the parts store pump and sent back my old reservoir and internal pump housing:grin2:

The rebuild on my new pump went smoothly (my first time doing such). There's not much of a guide on the forums but on Youtube there's a couple videos that show the basic premise. I might add that the snap ring that keeps the rotor seated on the end of the shaft was difficult to remove. I had a snap ring removal tool but it wasnt narrow enough. I had to take some very small needle nose to separate the ring some and then I used a 1/16" flathead to pry the ring off. The rebuild kit did not contain replacement snap rings for the large or small ones so be careful not to lose or damage them.
 
#30 ·
In the middle of doing the vacuum pump right now and I have a question. The Cummins kit instructions say to grease the seal before putting it in the housing but the Gould guy says to install it dry as does the Thoroughbred diesel guide.

Opinions?
 
#31 ·
For seals in general you aren't supposed to touch or apply anything to the inside of the seal.

You can probably grease or lube the outside to aid in pressing it in, just keep the seal surface dry.
 
#32 ·
I lube mine, never had a problem. It isn't a teflon seal like the front crank seal.
 
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