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Engine/Transmission (1998.5 - 2002) Mechanical Lift Pump?

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I had a RASP(DTT used to sell it years ago) belt driven mechanical pump and had no problems with it at all. It had a good 100k on it no belts broke no leaks etc. There is a fair amount of plumbing involved. The only reason I dont still use it is I put in a cam that had a lift pump lobe on it which allowed to me to use the mechanical lift pump out of a 12 valve truck which got rid of all that extra plumbing. I am guessing here but one of those setups is going to cost somewhere in the neighboorhood of $600 maybe a bit more. You can pick up a cam for 600ish and if you can install it yourself a 12v lift pump for another 100. Otherwise you have to pay for cam install which would probably more than double the price and take it to 1200-1300.
 
Hi,

my truck is got a cobbled system on it now (1 carter on the frame rail and factory in-tank) so want to strat from scratch so to speak

I went and order a system so hoping to get it by this weekend as need to get the truck back on the road

Thanks for the idea and feedback, I really have not found any bad write ups on a mechanical system yet vs. the tons of postings for electric ones

I will hopefully be glad I won't have to constantly stare at the fuel PSI gage and wonder if it is all ok

Will let you all know how it goes,
 
The ultimate lift pump fix! It's been around for a while and has always been my favorite fix, but it's only for those willing to do some engine wrenching to fix the problem. If I recall, you have to make sure you use the correct 12V pump. If I recall further, it was a piston pump design but the pressure wasn't the same as a typical 94-98 pump. You want the one with the lower pressure, as the typical pump puts out way too much. Remember the Cummins part# for the correct pump BarryG? I don't believe the diaphram pump for 1st gens produces enough volume to work... which is why the piston design was favored in a low pressure version.



I also used to like the idea because there wasn't any pressure-up until the engine started cranking. And you get the hand prime pump. Which some consider a hassle, but I consider gold when you have a 24V VP44 that's cranky about electric pump priming. Mine was.
 
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Sounds like a neat fix though I really dont want to get into swapping out cams etc, the fuel system is bad enough, going with a GDP system so hoping this is the last time I will need to start any post regarding lift pumps if you know what I mean

Thanks again,
 
NCostello:
I just used the lift pump from a 98 if I recall. It does put out way too much pressure for the vp. However since i had a RASP system on previously I already had a regulator as the RASP and I suspect any of the mechanical belt driven ones do as well for this application. I had a pressure problem once and while narrowing down the issue I took the regulator out temporarily (like for 5 minutes) it pegged my pressure gauge at 40psi and caused my stock fuel filter assembly to leak a bit at that pressure. I quickly decided my pressure problem was with the regulator and rebuilt it and no problems since. It had a god 100k on it and it just didn't seal well or open and close properly so I bought new guts to it.

Jmos
I have not heard anything bad about the GDP fuel boss. The design is very similar to the RASP. As I mentioned your plumbing will increase. Now the RASP unit I bought 10ish years ago if not the first one of the first of its kind in this application. I had to replace the front seal a couple times one you need to be careful not to have the belt too tight it is actually quite loose with the proper tension but I am sure GDP will give you the proper amount of deflection to look for on the belt. On the RASP anyway the front seal was totally exposed to road grime and dirt. Once I figured out it was just dirt getting into the seal ( $2 part and 15 minutes to replace) from the outside I just got the smallest, fattest rubber oring I could get on the shaft and pushed it up all the way to the front seal of the pump and I never had a seal go out again. It acted as a first line of defense for dirt etc getting to the seal and probably sealed much tighter than the actual seal did but then again the shaft didn't have to spin inside of it either the oring just spun with the shaft. In any case I was going through a seal about every 25k after my little oring mod I had another 75k on it when I took it off with no leaks.

The rasp install looked daunting and it was a bit time consuming iirc approx 4 hours but it is relatively easy.
 
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