Bosch 044 Install With Custom 5/16th Fitting, Drops In, New Option


Well-Known Member
Dec 15, 2002
Well, this wasn't that hard and I'm not sure why in 2010 we finally have this awesome option. One $35 SS fitting later and we're running with the best bang for the buck pump out there.

I'd like to get petty and thank Walbro for inspiring me to pull this off so less of us run their pumps.

Here is what you need, aside from Bosch 044 of course.

1) Custom 12mm x 1.5 to 5/16ths fitting. A touch over 1/2 long tube. (I will have for sale in Parts Section)
2) M6 x 1.0 and M5 x .8 nuts (10 and 8mm wrenches)
3) 1/4 Ring Terminal for Positive Post (if using Racetronix Denso harness the neg post terminal is the same at M5)
4) Two Stainless hose clamps and a 3.5" Clamp for Bosch to Return Tube. (found it at Pep Boys, Ideal brand)
5) Metal Cutters (for return tube base hoop and lip of gas tank)
6) Hose cutter
7) 3/8 or 5/16th hose (get extra just in case you need to recut due to angle needed)
8) Hacksaw (for Rheostat nub removal)

Ok here is an overview.

Use the brass washer that comes with the Bosch 044 fitting.

Use a deep 17mm to tighten the fitting into the Bosch.

Connect your ring terminals to the 5mm neg post and 6mm pos post.

Make sure you cut the hose on an angle, this is needed because the pump is fatter than the Walbro or Denso so the outlet fitting is a bit off centered. I believe the size is 1 5/8 and angle it up to around the 1 1/2 mark. This will allow you to have hosing completely around the fitting for clamping.

You need to cut off the return tubes base hoop, it will not allow the Bosch to rest flat against the tube, thus making it get into the tank impossible.

Clamp the SS 3.5" clamp with the nut end just behind the float arm, this will hide it from the gas tanks lip and make it easier to get into the tank.


I tried to estimate where the old pump and strainer where sitting depth wise and tied up the Bosch to around that depth. This way you are guaranteed that the pump has access to fuel and not right above the stock tanks sump.

When putting the hose on, make sure you spray it up so you can get it as high as possible on the outlet tube. Then I attached it to the fitting and THEN attached the pump to the return tube. If you attach it to the return tube first, the angle on the hose makes it difficult to get it flush with the fitting for a 360 of hosing around the base of the fitting.

This part a lot of you might not like, but, you have to cut off the Rheostats nub and cut an opening in the tanks lip and seal for the O Ring.

Simply just take a hacksaw and cut the nub off the Rheostat.

Then I cut smaller chunks of the tank and then pried them back with pliers.

When the pump is in the tank about half way, then bend these pieces back so the O Ring has a place to rest again. If you don't bend these pieces back to the proper height, it will make it harder to get the ring to seat around the Sender for tightening it down.

BTW, you don't need the strainer or pump sock, the pump has one already built in. This is how I knew we'd be able to pull this off since I also knew the Bosch had a HUGE fitting that came with it, something like 2 1/2 long if I remember correctly. Also, the Bosch has a check valve as part of that huge fitting, this means your fuel pressure will not drop quicker after you shut off the car. No biggie since we have a 3 second prime, fired up the same as the Denso all night long tonight.

Well, there it is. Fired right up after 4 on offs to get it to prime.

I hope a vendor will sell this pump for us, but for now, I got it at Titan Motorsport for $175.

I will have the fitting for sale for those of you who want to move up to the keg can of fuel pumps for $35. I can see what an aluminum one will cost for those of you not running E85.


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I forgot to take a pic of me bending the tank lip back for the Senders O Ring to sit around it. You do this when the pumps 1/2 in the tank.


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Do you use any type of filter sock with this set up? im definently interested in a fitting.
have you tried to fill the tank yet?i would think it would leak.

Nice job and very descriptive post but, I don't know about cutting the o-ring seat. I'm thinking that will leak. I hope you keep a close eye on that.
You don't need the filter sock, it has an internal strainer. If you've seen those who use it as in inline, they generally don't have a post filter due to this reason.

Concerning the lip and leaking, I mentioned how you bend the lip back into the stock location and then the O Ring goes back around it to seal it.
Concerning the lip and leaking, I mentioned how you bend the lip back into the stock location and then the O Ring goes back around it to seal it.

Even after you bend all those cut tabs back down, and lay the O ring down, there's still the cuts under the O ring. How can it seal those? They run all the way under the O ring.
Ok I'll let the paranoia experiment end.

I had an 1/8th tank, then filled it up 18 gallons until the nozzle clicked off, needle is BURIED past Full.


There's still a huge o-ring sealing the sender with pressure from the locking ring above.
I think part of the reason to have the strainer is to keep the pumps inlet wet when the gasoline sloshes back and forth in the tank.

Could be wrong.. :confused:
If there was a way to mount the Fuel Level sender somewhere other than the fuel pickup. Maybe a plate with a tube or rod welded to it with the fuel level sender mounted to it. The plate then mount it to the top of the tank next to the pump access. You would only need 3 or 4 bolt holes in the top of the tank to mount this assembly. It shouldn't be too hard to seal the bolt holes. You could drop this assembly into the tank and bolt it up, then connect some longer wires from the Fuel level sender to the regular connections on the fuel pump support. And then without the fuel level sender on the pump support you could drop in the fuel pump without the cutting up the o-ring sealing surface.

Also isn't the reason for the fuel pump strainer to give you more surface area for filtering the fuel so you don't plug up the strainer in the pump so quickly.

I'm sure you can fit the strainer that sells since there is still some hosing you can make a tad shorter. But I think it would be a close call with the dog dish and strainer, aside from it costing $50.

I ran the car with it on close to E initially, did a few 10psi pulls to make sure pressure was 1:1 and to see how it would respond with a low tank, all good. Then poured in 5 galls to get me a tad over 1/8th and drove around for another 20-30 miles, needed to find some E85. Then topped it off to see if it would leak, nothing there too.

So far, so good and I won't be returning to the past 24 years of intank fuel pump limitations. ;)
This would be cool. I tinkered with it couple years ago and could not see how it would fit in the tank with the plastic baffeling surrounding the stock pump.
More pictures of how you "mounted it" would be great.