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  #1  
Old 09-12-2010, 06:47 PM
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eliminating primer pump

I am chasing down an air leak and I think the source of it is the primer pump. It is the upgraded black body pump I put in 2 years ago but I think it's junk being $10. I want to eliminate it altogether and just use a mighty vac to prime when needed. The primer pump sucks anyway because you have to pump it 150 times for it to do anything and that is ridiculous. Do I just plug the hole up vacated by the primer pump? Has anyone done that?

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  #2  
Old 09-12-2010, 06:56 PM
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If that what I thought here is what I would do

It's real easy - just plug it with JB Weld. Well, maybe better stay with a plug with the correct thread in case you want to reverse your plan in the future.
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1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
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  #3  
Old 09-12-2010, 07:03 PM
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Quote:
Originally Posted by funola View Post
I am chasing down an air leak and I think the source of it is the primer pump. It is the upgraded black body pump I put in 2 years ago but I think it's junk being $10. I want to eliminate it altogether and just use a mighty vac to prime when needed. The primer pump sucks anyway because you have to pump it 150 times for it to do anything and that is ridiculous. Do I just plug the hole up vacated by the primer pump? Has anyone done that?
I am going to remove mine for the same reason. I will be adding a electric boost pump back at the tank to raise the primary fuel pressure and help feed the lift pump.

I considered putting a ball valve between the primer and the lift pump to isolate the primer, but that would be bulky and not at all sightly.

I am going to make a plug that screws in the primer hole and extends down into the piston return spring cavity because I do not want air to be trapped in the top the threaded primer cavity. I have an old lift pump to design from and need to refresh my recollection of what it should look like, but I think if you just screw a regular plug in the threads, you will get air trapped under the plug.
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  #4  
Old 09-12-2010, 08:07 PM
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Quote:
Originally Posted by funola View Post
I am chasing down an air leak and I think the source of it is the primer pump.
Is fuel leaking from the hand pump? If you don't have any external leaks, I would look for internal leaks, like at the lift pump, that are sucking air in from the fuel tank via the return line. I just had that very issue. Turned out that the discharge valve in the lift pump wasn't closing.

Last edited by qwerty; 09-12-2010 at 09:25 PM.
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  #5  
Old 09-12-2010, 08:40 PM
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Some Members have siad that the Hand Primer copies that are not made by Bosch do not hold up.
Bosch claims to have Viton Seals inside.
http://www.boschautoparts.com/DieselParts/Pages/HandPrimers.aspx
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Last edited by Diesel911; 09-13-2010 at 12:00 PM.
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  #6  
Old 09-12-2010, 08:47 PM
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The 60X motors dont have hand pumps & dont have problems so it should work.
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  #7  
Old 09-12-2010, 09:44 PM
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Quote:
Originally Posted by OM616 View Post
I am going to remove mine for the same reason. I will be adding a electric boost pump back at the tank to raise the primary fuel pressure and help feed the lift pump.

I considered putting a ball valve between the primer and the lift pump to isolate the primer, but that would be bulky and not at all sightly.

I am going to make a plug that screws in the primer hole and extends down into the piston return spring cavity because I do not want air to be trapped in the top the threaded primer cavity. I have an old lift pump to design from and need to refresh my recollection of what it should look like, but I think if you just screw a regular plug in the threads, you will get air trapped under the plug.
I found the perfect plug! I saved the old white bodied hand pump and cut it apart. Here are a few shots of it cut apart. It is made of the best materials, aluminum and nylon and some kind of rubber seals.

Which electric lift pump are you adding and why are you adding it?

The plunger is threaded nylon (piece on right) which threads into the base. C.W. is the stow position and seals the lift pump hole.


Both pieces threaded together


There is a cavity about 1/4" diameter 1/2" deep which can trap air but I will fill it with JB Weld.
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  #8  
Old 09-12-2010, 09:48 PM
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Quote:
Originally Posted by qwerty View Post
Is fuel leaking from the hand pump? If you don't have any external leaks, I would look for internal leaks, like at the lift pump, that are sucking air in from the fuel tank via the return line. I just had that very issue. Turned out that the discharge valve in the lift pump wasn't closing.
There is some wetness at the hand pump that's why it's suspect. I hated that thing everytime I used it so it's going away.
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85 300D turbo pristine w 157k when purchased 161K now
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  #9  
Old 09-12-2010, 10:48 PM
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An outboard fuel line prime pump works great on my 603. May be suitable replacement for your pump.
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  #10  
Old 09-13-2010, 01:15 AM
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Details!

Quote:
Originally Posted by NJ300sdl View Post
An outboard fuel line prime pump works great on my 603. May be suitable replacement for your pump.
Would you please supply details on your outboard fuel line pump... where did you get it, where did you install it in the lines, etc?

Thanks,

Kurt
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  #11  
Old 09-13-2010, 02:48 AM
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Arrow

Quote:
Originally Posted by gastropodus View Post
Would you please supply details on your outboard fuel line pump... where did you get it, where did you install it in the lines, etc?

Thanks,

Kurt
Pretty sure he means something like this the attached picture. It goes in the supply line just like a pre filter does.
Attached Thumbnails
eliminating primer pump-stccombulbpump.jpg  
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  #12  
Old 09-13-2010, 03:18 AM
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Quote:
Originally Posted by funola View Post
Which electric lift pump are you adding and why are you adding it?
I picked up a twin fuel pump setup off of a 420SEL. I am only going to use one of the pumps for a "boost pump".

With out going into detail, I am building a Super MW IP and want the supply fuel pressure to be around 60PSI.

I changed the lift pump spring and am running 30-35 PSI now. The regulated Boost Pump Pressure will act like an additional spring and increase the out put pressure capability of the lift pump. It will also help supply the lift pump, as pumps in general do not pull fuel very well.

Quote:
Originally Posted by funola View Post
There is a cavity about 1/4" diameter 1/2" deep which can trap air but I will fill it with JB Weld.
Personally, I have used JB Weld for emergency fixes, but I would let some of it set in fuel for some time to see if it starts to dissolve or do something undesirable before I put it in the IP fuel system. Just my 2 cents.
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  #13  
Old 09-13-2010, 09:53 AM
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JB Weld is just a very good epoxy, epoxy will hold up to diesel fuel. I have tested it and no problems in 5 years.

Are you putting the electric pump in series, before the mechanical piston lift pump? The mech lift pump pumps increasing volumes of fuel with increasing RPM, being a positive displacement type pump. Have you verified the gasser electric pump can keep up with the volume demands of the mech pump and not starve it at the higher RPMs?

Quote:
Originally Posted by OM616 View Post
I picked up a twin fuel pump setup off of a 420SEL. I am only going to use one of the pumps for a "boost pump".

With out going into detail, I am building a Super MW IP and want the supply fuel pressure to be around 60PSI.

I changed the lift pump spring and am running 30-35 PSI now. The regulated Boost Pump Pressure will act like an additional spring and increase the out put pressure capability of the lift pump. It will also help supply the lift pump, as pumps in general do not pull fuel very well.



Personally, I have used JB Weld for emergency fixes, but I would let some of it set in fuel for some time to see if it starts to dissolve or do something undesirable before I put it in the IP fuel system. Just my 2 cents.
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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked
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  #14  
Old 09-13-2010, 11:33 AM
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Quote:
Originally Posted by funola View Post
Are you putting the electric pump in series, before the mechanical piston lift pump? The mech lift pump pumps increasing volumes of fuel with increasing RPM, being a positive displacement type pump. Have you verified the gasser electric pump can keep up with the volume demands of the mech pump and not starve it at the higher RPMs?
Pumps will be in series. As for my desired pressure @ volume, all is good.

I think I saw some ware that some one was going to eliminate the lift pump all together and just use one of these pumps with a voltage regulator to regulate pressure.
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  #15  
Old 09-13-2010, 11:41 AM
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JB Weld holds up well

Some years ago while hunting in SD, I opened one fuel tank, (gas) on my Ford Van driving over a large rock in a field. I repaired it with JB Weld. When I sold the van a couple of years later, the JB Weld was holding the gas in very well, and it was a big crack. It was a plastic tank, but I have no doubt that it would work as well on steel or aluminum.

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Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!
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