Fuel return Chcke valve

rev10eight

I was changing/checking some fuel lines today and this snapped off. One line of the mechanical pump goes to the carb. the other side goes to this valve and then back to the tank.

Is this anything special or will any old check valve work?

MazdaMitch

Can you provide an under hood, pic of the area?

rev10eight

MazdaMitch
Does the fuel pump already have a built in check valve?

MazdaMitch

Someone added that, and it's a terrible attempt at a fuel filter.
Let me get a pic.

Cusser

That inexpensive filter is on the VENT line from the fuel pump, not needed there !

What's wrong with the factory fuel filter set up? Even I retain that and also have an inline metal filter after that to catch any little particles from getting into my Weber idle jets. Since 99% will get captured by the stock-type filter, I have yet to change the second filter in a decade or more.

rev10eight

No, that was in the return line already going back to the tank.

This originally had the in tank fuel pump for the automatic
that I removed and added the mechanical fuel pump.

There use to be a fitting where the mechanical pump is now.
A fuel line went into that tee'd. At the tee, one line went to the carburetor,
the bottom of the tee went to this thing and back to the tank.
Ill put it back together miniaturized and take a picture so you can see.

rev10eight

ah, ok. If its not needed, Ill delete.
I figured it was a check valve to prevent back flow and prevent over pressure.
If to much pressure was ever going to the carburetor, it allowed it to go back.

MazdaMitch

rev10eight that's what the return is for.
Get rid of the hokey auto split thing setup and just run a straight hose from pump to carb.

MazdaMitch

A proper fuel filter.

Only use OEM pump and these are the designations.

rev10eight

Yes, thank you much Mitch,

You are correct on the way a filter is supposed to be, and that is the way I have mine.
No dispute.
This was a check valve on the return line to the tank.

MazdaMitch

rev10eight I know...and it's not on any unmolested Mazda I've ever seen. Someone put this on there and it's unnecessary.

You want unrestricted flow BACK to the tank.

rev10eight

MazdaMitch
Thank you for your assist and patience. Sometimes its hard to get on the same page when were posting.
I think we were all posting and responding at the same time..
There was no argument from me, just trying to explain what I had going on.

Didn't know it had been changed. It had been hookd up like that for
the 12 plus years I've had it. looked factory before I dug into it.
Ill take it completely out of the system.

MazdaMitch

rev10eight Mazda did a bunch of unnecessary mess with the autos and there was no reason too.

The fuel filter by the tank
The fuel check valve on the return line
The Tee
The electric fuel pump in the tank

Crazy stuff.

Axel-Breaker-Earl

The original Mazda check valve was a metal unit.......here is one on a auto trans truck that I put a Weber on for a friend of mine. I eventually went back and re-routed the fuel hoses differently......I had to get the truck back to him ASAP after the carb swap.

We left the in-tank fuel pump also, so that is why I left all of the fuel hoses as they were initially.

rev10eight

Yes.. that was it exactly!
I forgot about the double connector where the mechanical fuel pump now is.

It then went to that hokee looking tee before the carb. The only difference was- mine, (when I got the truck) had the plastic check valve.

My mistake was thinking I needed to put the check valve back in. Don't need it now that I went with a mechanical fuel pump. Pulled the old electric out of the tank.