I had posted this on &quot;the other site&quot; but wanted to put it here. There was a comment that this would only work if the filter screen was clogged. I'm thinking that there's more to these lift pumps losing pressure than that. I'm thinking that the rubber gasket that holds the steel cap that holds the pump vanes in place is compressing and allowing the vanes to ride out of their run. The quick solution is to turn the rubber gasket over on the pump cover. Anyway, decide for yourself. My opinion is, if the pump is spinning and there is no noticeable wear inside, then pressure loss is a result of longitudinal movement of the veins.<br><br>I'm looking for some input in exchange for some good information. <br><br>First, the information. <br><br>I stopped by my local Turbo and Diesel Electrical Repair place today. It's where I get most of my work done and I buy parts there as well. The owner is one of the most knowledgeable guys I know when it comes to pumps, turbos and diesel engines in general. He owns a 98 24V 3500 and has always given me good advice. That's my disclaimer. <br><br>Today's discussion with him centered around the VP44 and lift pumps. I told him I had changed mine last year and he asked if I kept the old one. I had in case of emergency. He told me to take off the top cover, held on by the three studs. He warned me the studs would be loose. They were. He said that's the major problem with these pumps and why the pressure at WOT goes low on them after a few weeks/months. He has seen &quot;failures&quot; (low pressure) two weeks after installing a new lift pump. <br><br>One of his technicians tried something on a low pressure pump that brought the pump back to life with the correct/normal operating pressure. I was doubtful, but I did it. What I want from you guys is to try this on pumps you have removed and see how they work. <br><br>Here it is: <br><br>1. Remove the cover by backing out the three studs. It took a flat scraper to get mine to break loose. <br><br>2. The gasket along with the steel plate that holds the vane pump section in will come out all stuck together. Keep track of which side of the steel plate is to the vanes for reassembly. If you lose it, the side against the vains will have a circular mark about 3/16 in diameter where the vane holder has been running. <br><br>3. Remove the filter screen. If it's dirty, clean it. Try not to bend it from it's circular set or it will be hard to hold in on reassembly. <br><br>4. Remove the vanes and holder. Be carful not to drop or lose the vanes. You don't want them scarred or scratched on the rounded edges. If the rounded edge has become flat, flip the vane on reassembly to get a round edge against the inside of the run. <br><br>5. With a pair of needle nose pliers, gentle turn the shaft of the pump. It's the flat thing you see after removing the vane holder. It should turn freely. <br><br>6. Reinstall the vane holder and then slide the vanes into the holder. <br>7. Install the flat circular steal piece over the vanes and reinstall the filter screen making sure it's all the way in. <br><br>6. Flip the gasket over. Reinstall the gasket flipped over from the way it came out. Its easy to see how it goes. There is a curved indention in the gasket from pressed into the pump body. That will go up or against the cover plate on installation. <br><br>7. Reinstall the studs. Don't overtighten but they need to be snug. Mine were loose when I removed them. <br><br>Total time was 15 minutes and mine was finished. <br><br>Now the request: <br>What I want to know from you guys is whether this works or not. My friend at the turbo shop says it has worked on everyone they've done this way. I believe him. What I want to do is whether or not this is a good &quot;do it yourself&quot; project or if it takes a special talent to make it work. I don't have time to try it on my truck or I'd give you the results today. It's definitely something that may get you home in an emergency.<br><br>

 

Smoke Dog<br><br>Thanks a lot, I have printed this for future reference if I should have a lift pump problem. So far I do not.<br><br>Dan<br><br>

 

Smoke Dog,<br><br>If you look back a bit (page 2 on &quot;Help&quot; I believe) you'll see that I just put a new lift pump on my '99 CTD. (Mr45 from Bend, Oregon came down and helped me do the swap). <br><br>I read your post and tried that on my old (stock) pump, and it works fine now. I suppose that I have a good spare now. Too bad that I had to pay for a new one and install it, but I suppose I learned a lot about my truck's fuel system and met some neat folks here to walk me through it too. Based on what you wrote, and I tried: I could have done this &quot;roadside&quot; and been alright! Good info...<br><br>I hope you get the word out about this, it's a really easy fix, for the ones that the actual electric motor is still good in. Heck, there wasn't even any particles on my screen, the pump just stopped pumping. <br><br>Good read, and well written by you too! <br><br>Cheers, <br><br>Pete

 

McGyver, What I'm interested in finding out from those that try it is if the pump pressure comes back. Did it make sense what I am suggesting about why the pump is losing pressure now that you saw how the gasket might be compressing? You can't buy a rebuild kit for these things. I would like to find a good gasket material that seals and holds that plate at the right tension against the vane pump. <br><br>Thanks for letting me know the instructions worked.

 

Smoke Dog- If you could supply a drawing of the desired seal, I could look into it. One of the biggest automotive supply injection moulding companys is my customer. Another customer is a company that makes small series and sigle peaces of special hydraulic seals for the prototypes... Maybe they have something on the shelve. ( Or can fab it up cheaply.)<br><br>AlpineRAM

 

OK. I'll give it a try. I don't have a digital camera, so I'll have to figure out how to get it to you.

 

SmokeDog,<br><br>Carter makes a bazillion of these pumps. You can buy them for your RV for about $68 (goodie guy price) BUT, they are not a &quot;banjo bold face&quot; with 10mm x 1.50 threads. A guy could technically cut the Dodge ends off of your fuel line and push them onto the flanges and use a hose clamp to save money and get past Cummin's $$ pumps. <br><br>NOTE:I have a call into the Tech guy at Carter to see If he will sell the &quot;Cummin's&quot; pump with Banjo bolts, to the public through NAPA. The part # for the fuel pump that matches exactly (but the threads) is P4601HP. It's the EXACT pump with the exception of the &quot;Banjo&quot; face. I'll let you know what I find out. <br><br>P.S. The Carter pump should offer a kit for rebuild of the seals and veins! I'll check on that too! <br><br>To answer your question, I flipped the rubber gasket and slightly rotated it, and I have good pressure, almost like new. It was indented, and my studs were loose, as your friend said...<br><br>Things that make you go: &quot;Hmmmmm?&quot;...<br><br>Cheers, <br><br>Pete

 

I have not had to deal with the lift pump yet, but I was wondering if it would be advisable to check the bolts on mine and see if they are tight.<br><br>Opinions please<br><br>Dan

 

Dan, The only way to do it is to take it off. I asked my buddy was it worth it. He said yes, that the gasket compresses and the bolts (studs) need to be snugged. He said to be sure and not overtighten or you will bind the vane holder. When he told me the success they were having doing this, I was a little doubtful. After taking the thing apart, I can see why this procedure probably works. He did tell me they had made a gasket and it worked fine and has been in service for the past six months with no degradation in pressure. He was going to check with the technician that made it and find what material he used. I'll let you know.

 

Thanks, Smoke Dog<br><br>Dan

 

Good thing I tightened my studs before I put my new lift on. The studs were loose on the old one which I still have. I gonna take it apart and do what you suggested and see what happens thanks for the tip.

 

Hey SmokeDog! I have lateset and greatest lift pump on my truck with only 8000 miles and 7 months, it died, pressure falling to near zero. I did the pump reworks as you suggested and it now produces 13 psi at and idle and around 8 WOT.<br><br><br>I was reading the factory sevice manual and it states that there is a valve on the return line fitting that opens at 14psi. This fitting is on the side of the VP44. I was curious about how much pressure our lift pumps can create. I filled a 3 gallon bucket full of fuel and rigged the pump up to a 12 volt source. I put a guage on the outlet of the pump so I could see how much pressure was created. I also had a &quot;tee&quot; in the outlet with a valve on it that bypassed the fuel back into the bucket. I could slowly increase the outlet resiction and read the gauge. I slowly turned the valve closed and found that the pump would only produce enough flow to create 14-15 psi of back pressure. At this point it is working very hard to achive this pressure. I could dead end the outlet and the pump is turning with about 15 psi. <br><br><br><br> My point is if the valve on the VP44 opens at 14 psi and our pumps only create 14-15 psi not much fuel is recerculating through the VP44 and they seem to be at their upper working limits all the time. <br><br><br> maybe I am way off base here but I thought that I would see what you all think.<br><br><br>Malcolm <br><br>

 

Thanks, Mac1. I appreciate the feedback. I have received a couple of private messages where it was suggested I might be full of it with the rebuild. I've done five so far and pressures are around 14-15 after doing this little number. As I suggest, it might not be a permanent fix, but it will get you going for a while if you need it. Although, I've got to say, my buddy at the pump/turbo shop has not had one come back to him in six months.<br><br>On your theory about recirculation.....the VP44 is only relieving overpressure. As a matter of procedure, guys adding two lift pumps in series can get into a situation where the truck might be hard to start because of overpressure. That valve has two purposes if it is the one I'm thinking of...first relieving overpressure and second to bleed off any air that may be in the lines as a result of changing the filter.<br><br>Again, thanks for the feedback, Mac1. I appreciate it, alot.

 

Gary, doesn't the VP44 rely on the LP to provide adequate fuel delivery for cooling and lubrication? I know they will run a long time with an inadequate LP but under hard loads I would think they would need them to ensure there's no starvation at the input.

On the starting problem I mentioned with dual, inline lift pumps, I would have to assume that the relief valve is not relieving enough pressure and that causes a delay in starting. I don't think it will totally prevent starting. I haven't experienced it myself, but I have been told of the problem of inline lift pumps causing starting problems by the guys at the Bosch shop. Maybe they are assuming the internal pump/relief valve is being overdriven by the high pressure from the dual configuration. I don't know enough about the internal VP44 to challenge their assumptions, but they really seem to know their stuff. Their recommendation is to setup the dual configuration so that the second pump doesn't come online until the engine has started.

Also, it is my understanding that the VP44 relief valve will release without the VP44 running as in the case of bleeding off trapped air between the filter and the 44. Isn't that the reason for running the lift pump multiple times after a filter change....to force that air through the relief valve and back to the tank before it goes through the pump to the injector lines?