Fuel Pump Check Valve Alternatives

[Captain Obvious]

The original Bosch fuel pump check valve is NLA and I've been messing around with alternatives. The original check valve has a 10mm x 1.0 threaded inlet and a barbed outlet to accept an 8mm hose. Can't get it anymore... There are other Bosch check valves available with a 10mm x 1.0 threaded inlet, but the outlet styles are different. Not a problem!

Here's the first alternative I've worked through. This one uses a 14mm thread taper seat style outlet.

Bosch part number 1 587 010 539

Here's a pic of the stock check valve on top and the 539 on the bottom. Note that the pump end threaded portion of the alternate is longer than the original valve. It is so long, in fact, that it will hit the armature inside the fuel pump if inserted all the way:

First, you have to deal with the longer threaded portion before you can screw the valve into the pump. If you don't you'll mess up the insides of your pump. I cut off a couple threads to shorten it. I used my lathe (because I have one), but you could just as easily use a hacksaw or file. Just make sure you pack the hole with some paper towel or something so you don't get metal chips inside the valve. If you can't deal with making it shorter, then you could just stack up a couple extra copper washers to take up the difference. Here's a shot of the valve after I shortened the pump end threaded portion:

Now about the outlet end. Here's a shot where you can see the tapered seat on the outlet end:

How do we deal with the outlet end? Easy... Just grab a fuel rail hose off a junked Audi. I didn't get the year or style, but they were easy to come by. I think a couple Audi models (and maybe even VW) used the same hose. Here's the alternative valve installed in the pump and the Audi fuel hose laying next to the pump:

You can get the hoses with the end attached with a clamp, or permanently crimped on like I did. Here's the conical seat on the fuel hose that mates with the check valve:

Here's another shot showing the printing on the side of the hose.

Attach the hose to the valve and then loop the hose around and clamp it to the inlet of the dampener. Done. Cheap and still available. And easier to change in the future if necessary in the event that it goes bad:

Only other complication was that the original hold down clamp for the original steel loop was too small to fit the Audi rubber hose through. I just used an appropriately sized cable clamp instead.

When I get another chance, I'll talk some about a banjo style as an alternative. I got one of those as well.

Edited May 6, 2014 by Mike
Modified per Cap O request.

[FastWoman]

Very nice, Captain!

[rcb280z]

Can't wait to hear results. I have had no luck with the ones I tried. However, mine were placed closer to the engine, on the return line. Held for about 2 hrs and bled off.

[Captain Obvious]

I already know the results... It works great. I actually put it on my car for the first time near the end of last summer, but was in too much of a hurry to take pics then. I knew I would be back in there again this off-season, so I saved the formal documentation until now.

So if you're waiting for testimonials about performance, then I've got that too.

On edit - About the pressure bleed... Even with the new valve my fuel pressure bleeds off in a couple hours as well, but it's not the check valve. Mine is either the fuel pressure regulator or an injector. Small enough bleed that I've still got fuel pressure even after I've crested the heat soak of a hot start, so I'm not too worried about it. It's lower priority now.

Edited March 24, 2014 by Captain Obvious

[EuroDat]

Looking good Captain. How did you go with the o-rings or did a miss a post?

Chas

[Captain Obvious]

Chas, I got the O-rings and the install went fine. I'm kinda flitting around between eight different projects and it slipped my mind. I was also thinking that I wouldn't post much about it until I had put fuel back into the pump and made sure that everything worked as intended with no leaks and such. So at this time, the O-rings are in, but untested. I know... What could possibly go wrong.

go wrong.

go wrong.

[Captain Obvious]

Flare style check valve not your thing? Here's a banjo style alternative I've worked through. This one uses a 12mm banjo style outlet.

Bosch part number 1 587 010 536

Bosch part number 1 587 010 537

And along with either of the above, you'll also need a 12mm x 1.5 sealing cap nut:

Bosch part number 2 915 142 018

or Mercedes part number 1239900053

Here's a pic with the original valve up top and banjo style on bottom. Again, notice that the alternate is too long on the fuel pump inlet side:

Give the pump inlet end the same cut off treatment:

Again the trick is the different style outlet end. For this one, grab a 12mm banjo style hose off a junker. I grabbed one off a Honda Civic since just about half the cars at my local yard are Civics. Here's the pump with the check valve installed and the Civic fuel hose laying next to it:

Cut the banjo fuel hose off at the appropriate length:

And put it in place. There might be other hoses that fit more natural than the Civic, but it failing other options, the Civic hose works. If you find something better, please post it up:

The other trick with the banjo style is that you have to cap the end of the valve. Bosch uses 12mm x 1.50 threads, so buy an appropriate cap (or find one on a Mercedes in the junkyard). Unfortunately Honda uses a 12mm x 1.25 threaded cap so the Honda caps won't work:

Here's the parts you'll need for the banjo alternative:

[EuroDat]

Nice work. Great research your doing. Both very good alternatives to a leaking check valve. I like the banjo version myself and Mercedes are easy to find here;)

You should write this up in the Tech section once your done testing. A lot of people go for a new aftermarket pump, but I prefer trying to keep the original and the work you have done here will help a lot of people do just that.

If your handy with silver solder, you could heat the banjo, remove the hose and solder your original piping in the banjo. You would need to re-bend it to match the new angle.

Chas

[mjr45]

Cap'n, just as an FYI that Bosch sealing cap for a banjo style line is NLA, so it'd have to be obtained from a bone yard.

[txvepr]

Your other option if you do not want to mess with your fuel pump is to go with an inline fuel check valve, say after the fuel filter in your engine bay. I did this to good effect until I'm ready to completely replace my fuel pump, which still puts out good pressure...

You can try AZ or CarQuest...

[Captain Obvious]

Cap'n, just as an FYI that Bosch sealing cap for a banjo style line is NLA, so it'd have to be obtained from a bone yard.

Hmmm... To be completely honest (and a little embarrassed)... I did not actually purchase one of those sealing caps for the banjo style. The cap shown in my pic is actually a Honda cap with the wrong thread pitch. I figured out the part number and verified that they were seemingly available on both RockAuto and ebay and called it a day. I figured that I had already spent extra money on several different check valve styles and for something as simple as that cap, I didn't need to buy one just to prove that I could.

So if you go to Rock Auto's site and hit the part number search tab at the top, that cap comes up for $2.40. Did you try them? It appears they have them?

If not RockAuto, they're on ebay. More money, but I'm sure they're available.

[Captain Obvious]

txvepr, For performance reasons, the best functional place for the check valve is back by the pump where it is on the stock system. But I agree that it would sure be convenient to have it up front.

With that in mind, I've identified and purchased a fuel filter that fits the stock mount and accepts an alternate check valve to be screwed directly into the filter. However, I haven't yet worked out how to easily connect to the other end of that check valve and that's why I haven't talked about that option.