Fuel sending unit

I currently have a fuel leak on the car. I brought the car to a local mechanic and after looking below the car, the guy said he couldn't find where the leak was coming from so he removed the back seat and removed the service plate; there's a lot of gas on the top of the tank. He said that the fuel sending unit on our cars in made of plastic and tend to crack over time, which explains the leak because of the pressure in the tank. Has anyone ever seen this? I've been quoted 185$ for part and 90 minutes for the labor. I've read a little bit on the internet and it seems like the sending unit cannot be replaced, it comes with the fuel pump. Am I correct? Any thoughts? Thanks

no, you only need the plastic housing/filter, under $50 and probably the rubber seal between it and the pump. The labor quoted is a fair price.
See:

http://www.mazdas247.com/forum/showthread.php?t=123726206

So if I understand correctly changing the sending unit will not resolve the issue right? Or are all these parts part of the sending unit and replacing the whole unit will do the trick but wouldn't be necessary?

The sending unit should normally be sold as a unique part, and it will in itself do nothing to stop the leak. The sending unit (with float etc.) gets removed from the old pump housing/filter and installed on the new one. It just clips on and you hook up 2 wires if I remember correctly.

Ok I see... well I was a bit worried that the guy didn't order the correct part so I called him and he told me that the part he ordered is the fuel pump body... I know I heard him saying he needed the sending unit not the pump when he called the Mazda dealer but he told me that this is what he ordered... so I guess I'll see on Saturday if he was right and if this will fix my issue. I will keep you updated... I don't know if it's because I'm in Canada but you said the parts should be around 50$ well I called a local Mazda dealer yesterday and gave him the part number for the fuel pump body, he confirmed that was it, for a protege 03 and everything and the price is CAN$237.00!!!! I was like WHAT?!?!? 237 bucks for a little piece of plastic and the guy replied laughing saying they were rare and expensive.... So I guess for 185$ it's not too bad considering I know the place and the guy told me he would sell it the price he pays for it which is why I have it for 50$ less than what the mazda guy told me yesterday

Update on the repair... The sending unit was OK. When I brought the car the guy unmounted the fuel pump assy and said : who ordered that sending unit?!?!? And told the guy he was stupid right in front of me lool. The mechanic took Epoxy and put a whole tube on the top of the pump assy, had 2 little cracks, once solid, the glue was as hard as plastic. Had to use a grinder to remove excess that would prevent the assy to stick in place with the ring that goes on the top of the tank! So instead of a 300$ fix, cost me 100$. All good now, 1 week and still fine

I am having the same issue, Gas leak, Tank re-placed (Part of my safety check) still leaking why? When they re-placed the tank they had to removed the sending unit. However when they re-placed the sending unit they did a very fast job and the gasket was not in place and they re-used the same rusted screws on it, So they applied silacone so it would not move. Well silacone and gas don't mix, Results? It leaked and filled up under the rear seat and started to leak under the car. I went to my mechanic and I was told 254.00 for the whole unit, Then he noticed that my unit was not cracked so he would just replace the "housing unit" and gasket and screws cost 54.00 plus labour. I bought the car from a dealer and they have a garage that does the safety checks I did not get to choose where and who that why this happened.

If you have the same problem as I had, remove the back seats ( just pull them they will remove easily ) and you should find a service plate right there. Remove the 4 bolts and you will be able to access the fuel pump that is on the top of the tank. If you see gas, your problem is probably like mine : the top of the fuel pump assy is made of plastic and has a metal plate to protect it. The plate tend to rust over time and punch little cracks in the plastic. With the pressure in the tank, the gas leaks from there.... take a look at it, it will take you 2 mins. If you see any gas on the top of the tank, don't look any further.

gas tank leak on top!!!!!!

ChaRLeS23 said:

Update on the repair... The sending unit was OK. When I brought the car the guy unmounted the fuel pump assy and said : who ordered that sending unit?!?!? And told the guy he was stupid right in front of me lool. The mechanic took Epoxy and put a whole tube on the top of the pump assy, had 2 little cracks, once solid, the glue was as hard as plastic. Had to use a grinder to remove excess that would prevent the assy to stick in place with the ring that goes on the top of the tank! So instead of a 300$ fix, cost me 100$. All good now, 1 week and still fine

Click to expand...

I have a leak on the top of my gas tank. Went thru the trouble of removing tank and checking for leak. Finally decided tank itself was OK and was looking for leaks in hoses. All looked good till we tried to start up the car while keeping eye on hose connections ..... then we noticed gas coming out on top of the plastic. Am looking to seal up the plastic with epoxy like you mention. Do I need to open up the top and epoxy the the inside ring too? Could you please give me a little more detain on how yours was fixed.
Thanks.
Rudy.

Rudy if you are planning to keep your car for some time I would recommend replacing your sending unit housing (plastic housing) rather then taking a chance with a backyard repair. To conferm your leak location use some brake cleaner and spray the area completely which will bring back the white finish of the plastic, then once cleaned and dry turn the key on but dont start the engine (no need) and while holding a flashlight look closely to see the area it is starting from. You will most likely see a hair line crack with a small valley beside it showing where the fuel has been leaking. If you must and the area of the crack is in the area away from the fittings for the lines then scuff the area and apply your epoxy. Remember this is a short term fix as the fuel will be working it's way around the epoxy again.

Here is what you will need for the repair:

Fuel Body GY01-13-ZE0 {Shown as (2) Fuel Filter (high pressure) in diagram}
Gasket B25D-42-166
Plate BJ0E-42-16XE
O-ring ZL01-13-ZE5
Washer FEH2-13-ZE4 (may not be necessary)

You will also need the 8 screws that hold the ring in place as they will be completely rusted when you try to remove them.

The float, low pressure filter, and pump switch over to the new fuel body. The washer and O-ring seal the pump in the new body.