Jump to content

EFI petrol pumps and pipe unions . . .


fisha

Recommended Posts

OK folks,

Can any of you decribe what like the pipe unions are on an EFI style petrol tank from a late classic or P38 RR.

One of my unions has decided to blow and its literally Mildly miffed about 1/3 of tank out onto the road on the way home.

You now how they joke that you can see the fuel guage needle move towards empty when you drive a V8 . . . well you literally could in this case :o

I only noticed when the low fuel light came on and when I stopped, there was a pool of petrol oozin out from the tank area. :blink:

sooo, on the P38, the petrol pump is not accessible from a hole through the boot floor. You have to drop the tank. So in advance, can some of you tell me the types of unions and pipes that mate onto the top of a typical EFI pump.

cheers,

Donald

Link to comment
Share on other sites

Thanks for the offer. I was underneath it tonight having a look see at the setup.

It appears as though there is a couple of pre-shaped pipes which run from the pump to the edge of the tank where they then join onto the pipes that run the rest of the way forward to the engine.

I tried to undo the unions that I could see and was at the point of breaking them. So iwent no further.

Plan now is to source these 2 pipes new ( shouldn't be to hard ), drop the tank, replace them, replace the tank.

I think while the tank is out, I'm going to cut an access hatch in the boot floor so I can gain top down access like in the RRC. Should be a very simple job with the tank out.

Link to comment
Share on other sites

You may find that one of the two bent pipes coming out of the fuel pump has fractured. This is a common failure and means a new pump :( .

These pipes connect to a flexi pipe by compression fittings. The flexis then join rigid pipes on the RH chassis rail. (3.9EFI classic)

Hope this helps.

Link to comment
Share on other sites

mutter mutter - i hope not ! :(

i'll tackle taking the tank out on thursday

Hmm, I had a high volume leak from my P38a that was due to a fractured pipe where it comes out of the pump. Both pipes had severe corrosion and I had to replace the pump.

The steel pipes between the pump and the unions at the filter in front of the tank were in much better condition but had some corrosion. I chose to replace them with flexible fuel hose.

Dropping the tank is straightforward enough, but you need loads of ground clearance. If I remember correctly I needed all four corners on axle stands at full extension. If only it had an access hatch in the floor like late classics did.

Link to comment
Share on other sites

well, problem found.

Bishbosh wins the prize by saying the pipes coming out the top of the tank may be fractured. Only in this case, the return pipe was literally non-existant.

So, new pump time, and new pipe time. The pipe unions are not your average affair by the looks of it. They are not standard flare or double flare.

ho hum..... :rolleyes:

Link to comment
Share on other sites

So, new pump time, and new pipe time. The pipe unions are not your average affair by the looks of it. They are not standard flare or double flare.

ho hum..... :rolleyes:

Indeed, I believe they are compression joints with an olive. I replaced that lot with fuel hose and stainless hose clips. Come to think of it, I've got about 20m of fuel hose in the garage ...

Link to comment
Share on other sites

how did you mate the fuel hose to the fuel filter thats just in front of the tank? as far as I can see the filter itself needs the fancy union

did you cut down the existing pipe at the end that joins the filter and then stick the fuel hose onto it?

Link to comment
Share on other sites

did you cut down the existing pipe at the end that joins the filter and then stick the fuel hose onto it?

Aye. I used a standard plumber's pipe cutter to get a nice clean-cut end, leaving about 4in of pipe attached to the filter union. Push hose over pipe, another stainless hose clip and Bob's your Auntie.

Link to comment
Share on other sites

Earlier EFi Classics (up to about 91 when the 3.9 arrived) had rubber hoses with screw hose clips both at the tank and at the filter, from then on they were compression fittings on all connections.

The original pipes with the rubber hoses had a swage 'bulge' about 8mm from the end of the pipe to prevent the hose slipping off if the clip loosened or failed. I would recommend doing something similar if you put hoses on as a long term solution. One way is to crimp a compression olive in the same place, do not be tempted to flare the end of the pipe as that will cut into the inner pretty quick.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy